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The rope pump

1. Pumping head m 30 m 20m 10m Value Life Value Life Value Life Rope 1 10 Piston 0 80 20 Paint 3 00 24 Guide 2 50 48 Bearings 1 00 48 Outlet spouts 2 23 48 Raising main 5 23 Axle with pulley and pulley wheel handie 20 00 48 Manniy toa Smo re fie oe 186 Appendix Table A 3 Technified pump daily Pumping 1 5 m3 Pumping head m 30 m 20 m 10 m Value Life Value Life Value Life Rope Piston Paint Guide Bearings Outlet spouts Raising main Axle with pulley and pulley wheel handle 20 00 Rope Piston Paint Guide Outlet spouts Raising main Axle with pulley and pulley wheel handle 2 50 24 Monthly total mo 0 57 A Calculating maintenance costs 187 Table A 5 Technified pump daily pumping 1 5 m3 Pumping drop m 20m 10m Value Life Value Life Rope Piston Paint Guide Outlet spouts Raising main Axle with pulley and pulley wheel handie 2 50 Monthly total mo 0 48 188 Appendix Appendix B Materials tools gauges and molds in this appendix we present all the materials tools and molds needed for the production of the technified and user built rope pumps We also give approximate values for machinery as well as the tools required for making the molds We refer to tables A 1 and A 2 respectively Table A 6 Materials tools gauges and molds needed forthe construction a
2. 1 5 MEI 7 Fey oe IDS oe a 4 tn Fherope pump The challenge of popular technology Lat 7 RA re i re Ea u ma ai ion Se La oh y n N RGI Bernard van Hemert Osmundo Solis Orozco Jan Haemhouts 3 F Orlando Amador Galiz n ee a E e Rope Pump 1 The rope pump The challenge of popular technology Errata Unfortunately in the english edition of the book some problems occured in the lay out especially in relation to the mathematical symbols and the indices If you are just interested in the plain text you should not encounter mayor problems However if you are interested en the details of the calculations and formulas you will have to use this errata list For the apendix F Calculating pulley wheel and raising main diameters and the list of symbols the corrections needed were so numerous that decided to present these paragraphs integrally As mentiones in the book we remain interested in hearing any comments on the book as well as your experiences with the rope pump Arnhem december 1992 Bernard van Hemert Oude Velperweg 50 6824 HE Arnhem Nehterlands tel 085 649744 fax 085 644909 2 ERRA v Page 48 first paragraph line 2 3 and of greater depth should read even at greater depths v Page 99 first paragraph line 5 photo should read photo 16 v Page 110 and following the terms stabiliz
3. ed a lt y Aa e r pA Ai ce i i cate A ata Ni N ili DS SA eg Re Figure 6 1 Complete pump Chapter 6 Description of the pump 87 Chapter 6 Description of the pump In this second part which is directed towards the technicians who will design and build the pump we explain its construction and design in detail Following a more detailed genera description of the pump than in section 6 1 we have analyzed the different parts slab pulley wheel pistons rope and raising main guide and stabilizing stone discharge spouts We use the pump that DAR PRegion V is installing in the com munity wells as an example but always present other alterna tives We compare the alternatives in tables in which the option of DAR Region V is always in the first column and highlighted Where possible the characteristics are quantified but in some cases we give a relative comparative rating that varies between very bad and very good and Not all of the char acteristics are mentioned only those that demonstrate a differ ence between the alternatives lf we are aware of alternatives but do not have hands on expe nence with them we simply mention them in a footnote 6 1 General Description Figure 6 1 demonstrates a rope pump such as one installed in DAR Region V The visible part is made up of a pulley wheel handle which activates a pulley wheel which is connecte
4. the whiner for the sound produced by the wood materials This pump consisted in a series of recipients put around a wheel figure 1 3 which can be considered a compound of a series of levers distributed over a singie axle The lower part is submerged in water The wheel turns so that the recipients leave the water upright staying full until they reach the top As 10 First part The challenge of popular technology Figure 1 3 Figure 1 4 Norlia with chain Chain pump they go down the water falls out into a receiving canal Com pared with the earlier system the noria has the great advantage of allowing continuous movement with no dead time Just like the shaduf the noria continues to be a common mode of water extraction for many communities in particular combined with the tradition of animal traction The constructive logic is perfected with a variant of the same noria In which the wheel functions as a pulley which moves the recipients on a chain figure 1 4 Given that the height of the pumping no longer depends on the wheel s diame ter but rather onthe length of the chain the wheel s design is re duced to a pulley wheel which sustains the chain and transfers the motor force This implies a major reduction in its diameter and the necessary materials and increases the possibility of Chapter 1 A developing technology 11 Figure 1 6 Rope pump The next step pumping from narrower and deeper wells As the wheel
5. The second influencing factor is the diameter of the pulley wheel The combination of the crank handle and the pulley wheel acts like a lever if the pulley wheel is smaller the force felt on the crank handle is also less but in turning the crank the rope will also nse more slowly Less force needs to be generated but the volume of water lifted is also less If on the other hand the pullay wheel has a bigger diameter the force felt on the crank is also greater and the rope will rise faster with more valume As we will see in section 7 3 for greatest efficiency it is best to try to use the biggest possible pulley wheel In general we recommend the measurements shown in Table 1 The measurements are general recommendations and may vary according to the specific situation and needs of the users Chapter 7 Mechanical and Hydraulic Characteristics 121 Table 7 1 Recommended pulley wheel and raising pipe diameters onnaa fos vo wa wa ow Pulley wheel tire 20 20 20 Raising main 11 2 41 3 4 Effective pulley wheel diameter Opol mm 540mm 540mm 540mm 540mm 350mm Raising main diameter Otub mm 44 5 mm 30 4 mm 23 3 mm 17 8 mm 17 8 mm The shadowed ranges are the most common The calculations are noted in Appendix F We know that there are two factors that we can vary in order to optimize the system the diameter of the pulley wheel and the di ameter of the raising main As is seen in Table 7 2
6. is the gap between the piston and the ralsing main called b Chapter 7 Mechanical and Hydraulic Characteristics 125 As is seen in figure 7 1 hydraulic efficiency depends primarily on this gap the downward curves are steeper than in the other graphics Each tenth of a millimeter is important We also see that the efficiency of a wider diameter tube is better than that of a narrower tube This can be explained by the ratio of the sur face of the ring through which water escapes to the total surface of the tube This surface ratio for a gap of any given measure ment is always greater in narrower tubes than in wider ones Our experience is that the minimum possible gap difference in diameter between the raising main and a piston is 0 2 mm Such a smail gap can be successfully used only when the tub ing is of good quality and is installed with great precision Good quality tubing is judged by the uniformity of its interior di ameter see figure 6 6 its roundness and the absence of irreg ularities such as for example constrictions at the base of the flare The installers must work with great precision So that the pistons don t stick They must also be able to detect the inevita ble problems that arise with such little play We discuss this aspect more fully in Part 3 In less deep wells in particular it may be much better to allow for more play for ex ample a gap of 0 6 0 8 mm 126 Second part Construction Hyd
7. tub 2 rope 2 g Hhead 1 handle This formula can be simplified by introducing two combined vari ables C a constant N m Ltr and VOL rev Volume per revolution Ltr C 7 7 N m Ltr 2 rope handle VOL rev po1 1 4 tub2 rope2 10 6 itr 3 206 Appendix We note that the volume per revolution VOLrev combines the only two variable parameters that define the force over the lev er tub and pul In other words the volume per revolution is a measure of the forces acting on the lever Now we must take into consideration that the speed of the pis ton influences the hydraulic efficiency see appendix G The rotating frequency of the pulley wheel handie f assumed as opti mum for the user in the range of 0 7 1 s 1 defines Vpis speed of the piston varying between 1 and 1 5 m s while the optimum speed is estimated at 1 5 to 2 m s It thus implies at tempting to maintain pul maximum 540 mm which corre sponds to a rim of 20 and varying the diameter of the raising main tub Let s return to the calculations Introducing C and VOLrev equations 2 and 3 in equation 1 gives us Fhandle VOLrev C Hhead N 4 and also Pin Fhandle handle f W 5 With these formulas 4 and 5 we can calculate with ease the force on the pulley wheel handle and the input power required in the different cases Figure A 8 gives the force on the pulley wheel han
8. 14 Spoke 15 Strut 16 Feet 17 Base 18 Diagonal 19 Tube guide 20 Brake lever 21 Brake absorption 22 Brake support 23 Brake security 24 Brake bushing OOnN Ooh WN Material Tube Tube Tube 1 2 Tube Tube lron 1 4 5 16 1 x 1 4 strip sheet metal Iron Tire Iron 1 4 Iron Iron 1 4 Iron 1 4 Iron Iron 1 4 Iron 1 4 Iron 1 4 Iron Hose Iron Iron 1 4 Tube 1 2 Appendix quant MPOANNMANN A a 0 o O ae i i AQ A A Dal C Materials for the pulley wheel in hand dug wells Section A A 4 yia ihan dar i i Rope pump Be Raglen ee aring N SCALE ne i EEE xipusddy C Materials for the pulley wheel in hand dug wells 193 with hose Blocking system CALE 12 I sa o o ee a ss en e aa ae a ee oe eee a ZA rh OE a AAOOB DO Materials Total Matenal 340 ale pa Figure A 4 Gauges for Injected pistons D Specifications of the P E and PP injected pistons 195 Appendix D Specifications of the PE and PP injected pistons in this appendix we make some observations about the produc tion of PE and PP injected pistons the focus is on the molds and the injector machine Mold Figure A 4 represents the simplest form for a steel or bronze mold to inject the pistons All that is required for its fabrication is a simple lathe We do not give m
9. Frandie X Onandio X J X E W 5 With these formulas 4 and 5 we can calculate with ease the torque on the pump handle and the input power required in the different cases Figure A 8 not included in this errata see book gives the force on the pump handle as a function of the pumping head for a i peat w r Rope Pum range of five volumes per revolution used by the Region V DAR as reflected in Table A 3 Table A 3 Recommended diameters of the pulley and raising main depending on the pumping head The ranges In bold are the most common Tue tor pulley 7 Raging man 7 Pulley dtameler Qpul mm Rasing man diameter Otub mm Volume per revolution VOLtes Ltr As we have defined VOL we can take advantage of this entity to easily calculate the flow Qrea Qreal lya X VOL x f Lir s 6 With the calculation method presented in this appendix the force on the pump handle Fhandie and the entry power Pn can be easily calculated and thus the optimum values for the raising main w and the pulley diameter pu May also be determined We can also see how to calculate the pump flow Qtea w me m Advice printing and distribution Editorial enlace ok Translation Amy Banks Patricia O Kane Carrie Parker Donna Vukelich First English edition Janauary 1992 1 500 copies The production of this book was made possible thanks to financing from the Netherlands Development Organization SNV A
10. Use the system shown here t used since 2 years and has not given problems Strengthen the pumpstructure legs where it alii the forces see illustration Eventually use bars of 1 2 instead of 3 8 in case of community pumps deep wells 5 PISTONS AND ROPE The pumps installed 2 3 years ago often have original pistons mounted every 1 5 2m The efficiency has decreased Reasons In practice people change the rope when it is worn out starts breaking and leave the worn pistons This causes lawer efficiency The pumping time is longer to get the same amount of water This causes extra wear out of pistons and rope Suggestions e Put the pistons with less distance 0 5 1 m Though the investment at the beginning is higher in the long run it is cheaper because the pump is more efficient and the rope and pistons last longer Fastening the pistons with knots seems the easiest 6 Annex 1 The wear out of the PVC tube appears to be little Of all pumps installed in Nicaragua about 2000 in the last 3 years only some 20 are known where it was neccesary to change the tubes about 70 is installed on private wells 6 THE GUIDE page 201 203 The guides as demostrated have several problems like breaking especially the hollow type defects in the glazing or breaking during instalation or maintenance Also these types of guides are relatively complicated in production and distribution Suggest
11. ask the poor First part The challenge of popular technology RT SS SSS SATS S SSN TRIS SUNS SST Oe 2 _ tan n arenes ermerernes ereetrnw oe ANTANN 2 X Figure 1 0 Global sketch of the rope pump Chapter 1 A developing technology When discussing possible solutions to the problem of underde velopment through cooperation programs the deceptive image continues that these solutions can only be found in following the example and imitating the history of industrialized countries based on the transfer of technology The effects of implementation of technology however coincide with what those who develop the technology seek but do not necessarily equally benefit the others In certain cases the implementation of an outside technology can negatively affect the development of communities who have not participated in the formulation of that technology We have worked in Nicaragua based on these beliefs develop ing and implementing the rope pump that we will now describe Before describing the pump s implementation approaches in sections 1 2 to 1 4 we present in section 1 1 a concrete de scription of the pump 1 1 General description The rope pump is inexpensive efficient and simple Figure 1 1 demonstrates the pump set up The heart of the pump is a nev er ending rope with pistons This rope is raised through a raising main passes through a pulley wheel and falls free into the well Under the water
12. plex Only part of the problem has been Solved and it is still necessary to find a considerable variety of rawmaterial PE or PP six types of steel welding paint PE fiber for the rope tub ing clay and glaze A major part of the machinery is under utilized except for the welding equipment The experience and specific Knowledge existing in the special ized workshops is not utilized This form of production is not based on the existing small in dustry and this weakens the society s assimilation of the tech nology as discussed in sections 2 7 and 2 8 We recommend the organization of production based on a net work of existing small and micro businesses In order to achieve this it is necessary to support and control each of these mi cro businesses in the following aspects It is very important that the craftspeople understand how the rope pump works why it was designed etc through practice We have had very good results with this strategy as regards mo tivation as well as generating useful ideas regarding how to pro duce or adapt sub products Look for ways of payment that help the micro businesses to in vest and grow for example through payment in imported ma chinery 78 First part The challenge of popular technology ee le oes iy a ode i i Photo 12 Injection machine before starting on an order for 6 000 pistons The lever on the left feeds the raw material The polyethylen
13. creating the form first firing glazing and second firing We do this for both the solid and hollow models We consider some basic equipment and significant expe rience with ceramics to be essential if you do not have this it is better to choose another type of guide Given what has been stated above in this appendix we will use fairly technical language without attempting to explain to lay people all the different terms relating to ceramics Solid Guides High temperature with a vitrification point of 1 250 to 1 300 de grees stoneware clay should be used with little water absorp tion Capacity and maximum shrinkage of 14 Creating the Form Dry the clay breek and grind it mix it with water and strain with a sieve of 80 holes per inch 120 is better Extract the water from the clay slip until the mass reaches the nght consistency 198 Appendix Photo 35 Cinva ram with mold for a guide Within the cinva ram there can be distinguished three slabs which form the rear and the sides of the mold In the upper section shown by one of the cooperative members can be clearly distinguished the parts sticking out which will form the trough for the tube and the opening through which the pistons will pass There are two options for shaping it A mold with a cinva ram 15 machine While the clay is leather hard one has to cut the orifice that the piston travels through See photo 35 It m
14. general indications but always take into account that at the be ginning of the pumping all the water that is in the tubing must accelerate causing initial water wastage Chapter 12 Post mounted rope pump 173 Table 12 1 Choosing the diameter of outlet tubing for rope pumps on posts Available Diameter of outlet piping drop m 3 4 1 11 4 11 2 i 2 3 4 5 6 7 8 9 The table gives horizontal distances m over which water can be pumped depending on the diameter of the tubing and the available drop m It assumes a discharge of 1 1 liters second 12 2 Installation As with pumps for hand dug wells two half days are needed one for embedding the posts and the other for installation Before beginning it is important to think about the possibility of the type of outlet tubing to avoid having to make corrections from the top of the post 174 CASE 1 The supply tank is lo cated very close to the well and the outlet spout can go directly to it by air This situa tion is infrequent Fourth part Special Models VAEREEELLRED EEE os i j 3 4 A A H 4 4 J A 1 4 A rd A 9 3 A The destination of the water is far away and the entire pumping head is needed The depth of the well is less than the height of the post This is the least recommended option given the rela tive complexity of the tubing The depth of the well is much greater than the h
15. it may be easier to pass the rope through the individual tubes before join ing them together The rope can also be passed through the tubing all at once but this requires a huge length of thick iron wire 12 If the well is com pletely lined with PVC tubing the rope can belet down loose If the lining is made of iron or is only par tial the rope should be lowered through a protector tube for the entire depth of the well in order to avoid rub ure No 11 Stabilizi rock for bing wear and tied wells ii contamination This protector tube has the same diameter as the outlet spout and is joined to the guide in the same way as the raising main After having secured the guide joined the tubing and tightened the clamp attached to the cover the whole thing is lowered into the well Since the diameter of the pulley wheel is larger than that of the lining tube the rope will not simply lower into the well it must pass through the upper guide the same as with the 170 lower guide The upper guide is fas tened with rubber to the protector tube and or to a device welded to the wheel support or to the cover The rest of the in stallation is exactly the same as with an ordinary installation Extra materials needed in addition to those needed for a normal pump an upper guide the lower guide should be the type with two grooves for the two tubes protector tubing for the total pumping head
16. pipe cutting saw PVC glue hammer measuring tape pole to lift the slab thick fastening wire longer than the total depth of the well at least 7 meters are needed to fasten a tube cigarette lighter to burn the ends of the rope Optional materials two buckets bricklayer s trowel pipette for measuring the bleach Step by step Instructions Secure the pistons on the rope using a strand about 25 mm long braiding the rope and burning the ends See fig ure 8 4 A strand goes both above and below the piston The pistons should be se cured about 2 meters apart Make sure all the pistons are facing the same direction This task takes a long time Children can easily partici Figure No 8 4 How to attach pate the piston to the rope Chapter 6 Description of the pump 103 Piston Washer Downwatd Goward a e ie oe oe cee friction farces gt driving force between tube and pston washer from Tope on piston washer Figure 6 5 Forces acting on pistons vs washers The hydraulic pressure is not shown to avoid complicating the figure Notice that in the case of the piston the friction forces apply below the point of application of the force of the rope In the case of the washer the opposite occurs which provokes a lot of friction given the instability of the system rope comes out is as small as possible to minimize leakage and so that the tightness of the rope can di
17. signs exist that range from only wooden structures to turned ax les with ball bearings etc All of these are valid and depend on the creativity of the builder and the materials at their disposition However it is important to always understand the background behind the construction alternatives to be able to design correct ly under different conditions It is also important to monitor inno vations during a sufficient time period before implementing them on a large scale Alternative constructions We present here construction alternatives for three parts that have been discussed continually in Nicaragua in the last few years the blockage system the location of the pulley wheel the suspension of the axle and the pulley wheel protector Types of bearings Traditionally the rope pumps in Nicaragua have as bearings simply a fixed piece of tube within which an axle of 1 2 turns This construction does not permit the changing of pieces if a saw and welding is not used Particularly when the pump is em bedded in concrete it is extremely important to be able to take out the moving parts for any repair or change This is why we have designed split bearings cut from a GI pipe 4 We have tried a moving support structure attaching with an chor bolts embedded in the well slab similar to the system used with the Dempster pump but the screws suffered heavy corrosion f ae 98 Second part Construction Table 6 2 Adv
18. 8 years The maximum force on the bearings is at the same time a Measure according to the maximum load of the axle It is ex pressed as a factor of the static force of the weight of the water column which is assigned the value of 1 For the two models the same distance between the raising main and the wall of the well is assumed The distance between the pulley wheel and the manhole see figure 6 1 should be minimal to facilitate the dismantling installation of the tube of the raising main Second part Construction Photo 13 Blocking system system in the DAR Region V This system has the characteris The rod allows the pins welded to tics of a party nolse maker It is the pulley to pass in one direction strong but requires a lot of work but not in reverse and materials El Papayal Table 6 4 Advantages and disadvantages of two blockage systems No of stops per turn Maximum free angle Kinetic energy to absorb Arm mm Energy arm J m Shock absorption possibilities Ease of production and price Years of field experience 1 Chapter 6 Description of the pump 101 Note A blockage system design exists that consists of three teeth on the axle which although it does have enough strength is well distributed We mention this case because it is shown in various photos Location of the pulley wheel While the model described here has a pulley wheel outside the support the majority of the pumps in Nicaragu
19. Chapter 2 Basic rope pump concepts 35 However definitions of the concept vary so much that we prefer not to dwell on this term Many central elements in definitions of appropriate technology are the same as those described in this chapter We can confirm that the rope pump technology is an appropriate technology We now discuss each of the concepts that form the base of the rope pump as it has been developed and promoted in Nicara gua 2 1 A felt need by the beneficiaries One fundamental concept in all development activity and there fore in all drinking water supply projects is that it should begin from the interests and reality of those benefitting We must then first define who are the beneficiaries and the users of drinking water wells The digging and cleaning of a well is considered man s work Wehave experiences in which women participated actively in digging and masonry work but they are exceptions In this sense it appears logical to organize construction of new water works with the men However women are the most involved in everything which refers to the supply and management of drinking water in the house In this sense they are the primary beneficiaries In terms of pumping water the situation is more diverse We can make a general observation that throughout Nicaragua in the case of communal pumps women and children are usually the ones who gather the water On the contrary in the case of individual family
20. Component of ioss flow due to dragging of piston m3 s Loss flow Qpres Q drag Component of loss flow due to pressure m3 s Real flow m3 s Theoretical flow m3 s Piston speed Ltr Theoretical volume per revolution mm Play between piston and tube tub pis 0 2 1 Pump total efficiency hyd rope Hydraulic efficiency Qreal Qteor 80 95 Mechanical efficiency defined as lossfactor due to fric tion Fhandle teor Fhandle 80 90 Pi 3 1416 kg m3 Specific weight of water 1 000 m2 3 Kinematic viscosity of water 1 1C 6 218 Appendix List of abbreviations VLOM Village Level Operation and Management CITA INRA Appropriate Technology Research Center Nicaraguan Agrarian Reform Institute COOPINIC Nicaraguan Innovators Cooperative CEPAD Ecumenical Pro Development Committee DAR Rural Water Institute INAA Nicaraguan Water Utility PAHO Panamerican Health Organization PE Pulyethylene PP Pulypropylene UNI National Engineering University Consulted bibliography Ariosoroff S et al Community water supply The option of manual pumps The World Bank Washington DC 1988 Bailesteros Perez Miguel Angel Proyecto de mejoramiento de la bomba de mecate UNI Tecnologia de la industria Ma nagua Nicaragua 1991 Bargmann Dorie Presupuesto para bombas de mecate de madera Informe no publicadao Puente de Paz Managua Nic aragua 1991 Besselink J e a Behaviour of deepwell handp
21. Conditions a flat place near the well where the slab can be poured a paved space is ideal but not necessary the possibility of building a fire in the same place if this is not possible the flare can be made before going out to the well at least two people one of which should have experience in masonry availability of water to make the mix and to clean the tools previously determined diameters for the raising main and the pulley wheel Necessary tools a machete to clean the pouring area if necessary a pick to level the pouring area if necessary Chalk to draw on the pavement if there is a paved area for pouring a 2 meter x 2 meter sheet of plastic to cover the ground a strip of sheet metal tin 75 mm x 4 meters to make the out side slab mold 2 shovels for mixing the concrete mix 1 or 2 buckets 1 or 2 masonry trowels 1 or 2 pliers to twist the fastening wire a metal cutting saw a wood cutting saw 134 Third part Installation operation and management a rasp a hammer a plumb bob a 3 meter measuring tape a knife a bottle with a neck of less than 18 mm diameter Optional tools Carpenter square a 1 meter long board for evening out the surface a fine screen sieve to strain sand Materials 3 20 liter buckets of gravel 4 20 liter buckets of sand 100 lbs of cement 24 meters of iron rod 10
22. Local innovation The experience and creativity of artisans are essential to the ad aptation and development of the rope pump Their experience gives them a very different and many times more innovative vi sion than that of professionals Adaptation to local conditions When the artisan produces and installs the pumps and under stands the technology he can then adapt the design to changes in production conditions for example availability of materials introduction of new tools etc User maker relationship Local production guarantees a certain closeness between the maker and the user which facilitates spare parts supplies re pairs adaptations and even the development of special models adapted to the specific user s situation This closeness is a guarantee of quality since the maker is continually subject to quality control in practice by the users An extreme case of local production is user built as it was de scribed in section 1 4 In that case the future owner makes her own pump The great advantage is that the owner understands the technology and at any moment is able to repair it adapt it and change it Chapter 2 Basic rope pump concepts 45 2 7 Technology transfer A technology which sets out to be popular and democratic must be understood as much as possible both by the makers and the users This is necessary to guarantee adequate opera tion and maintenance but even more it is the greatest fruit for the us
23. Mount a PVC tube instead of a steel tube if cut lengthwise it can be changed PVC PIPE 9 MOUNTING OF THE PUMP TUBE rising main In many pumps installed in Nueva Guinea the PVC tubes are not mounted straight in the cover of the well causing wearing out of rope and tubes e j photo 22 The mounting demonstrated on page 109 and 136 functions well if made in this way but many of the pumps are installed with other materials Reasons e Lack of adequate materials and knowledge techniccal contro during installation Suggestions Line out correctly the discharge and return tube using a plummet and use the materials as indicated e Assemble a support in the structure of pump so that the pump tube is centralized automatically see illustration at number 5 4 Rope Pump 9 Tube 2 is 2x diam of tube 1 e g 1 1 and 2 2 Tube 3 is of same size as tube 2 Tube 4 is 1 size bigger as tube 1 e g 1 1 4 1 25 min In drilled wells it is better to use a return tube in handmade well less necesary itis likely that a small booklet will be made by COSUDE Bombas de Mecate S A about production instalation and maintainance of the recent Rope and Washer pump Appendix 227 We wrote it several Address Name Description Contact Address times but received no response Jiron Bolognesi 165 Puno Peru Loughborough University of Technol ogy Dep of Civil Engineering The
24. a guide assures the smooth en trance of the rope and the pistons into the raising main Turning the pulley wheel makes the rope move The pistons give minimum play in the raising main and suction the water up You could say that the whole raising main serves as a long cyl inder in which the pistons only move in one direction When it gets to the top the pumped water is diverted to the user s buck et 8 First part The challenge of popular technology The basic principle of the rope pump is that simple In chapter 6 we describe the pump with all its details The rope pump is highly efficient and pumps great quantities from 2 liters per second at a depth of 5 meters to 0 3 liters per second at a depth of 40 meters The pump is appropriate for in tensive use it has pumped up to 32 barrels daily 8 m Even more important than this data is the fact that the pump is easy to build operate and maintain The pump can be adapted to different conditions in the fourth part we describe special models for drilled wells to pump water above ground level pump on a post for pumping large quanti ties irrigation and run by a motor or a simple windmill Now that we know more or less what a rope pump is and what it can do we present a brief historical review and describe differ ent implementation approachies currently in Nicaragua 1 2 Some notes on the history of pumping technology This book does not aim to present the rope pump te
25. a right to participate Concepci n Sure there are a lot of differences and there exists more acceptance on the part of women think that part of this stems from the fact that generally the women participate more in dealing with water it is the woman who uses the water for all the domestic chores to drink to wash dishes to bathe the children All of this re sponsibility falls on the woman and it is also the woman that is going to be drawing the water And so she also uses the pump within the communities and tres to make a decision Hey this ts the pump that s right for a woman s strength because it is easier to turn the pul ley wheel more water comes out my container fills up more quickly and am going to be able to manage more water more efficiently So the women can make decisions regarding the type of pump be cause in making the comparison with another type of pump they feel that it is more complete In addition there are women who havepar ticipated in the installation and it is they who have had the responsi bility of repairing the rope pump because it is easier the accessories weigh less and everything is easier than the other types of pumps Concepcion It is popular because in the first place it is made from our own materials It isn t necessary to bring in parts from some where else and its cost is within reach of people with few economic resources It is democratic because practically everyone has th
26. and since it doesn t draw water that way there is less effort in pulling Who else participates or do you make the pumps by yourself explain to the pump owners that it is important that they pay attention when install the pump But there are those that must go off to work leaving behind only the women to help And the women are the more interested perhaps because they have had to haul buckets with thousands of problems So the womefri are the ones who are more interested Considering these materials only the ropes should give you trouble What about the guides They function but it is not the same because went about for three years working with that same foot valve which was already too worn out t isn t the same as with that ceramic isolator You can make them of laurel which ts a fine wood always looking out for wood that lasts long under Chapter 1 A developing technology i 21 water And explain to themhow it s made in terms of cost if the person is poor we help them If they have family members explain to them too If not put t together for free Do you think that someone with little knowledge yet familiar with agriculture and cattle ralsing could construct and Install a pump simply by observing your pump Many have brought pumps here but they couldn t install them have been installing the pumps for them They use 9mbaro wood for the guide and many have used the lever from a plow guide they tie up
27. decided to come up with better molds and designs We did a Structural analysis of the equipment in order to balance time and materials For example in welding during fabrication and assuring the proper balance of the pulley wheel we are now welding the pulley wheel and the handle at the same time Another example is using designs that cut back the need for materials In this way we save on production costs and then the prices are lower How do you make improvements on the pumps When we go into the countryside we like to see how they work What we do is get feedback from the installers for example the client doesn t like the Sound of the brake We have very good communication in this re spect We have improved many details such as the welded joints the parts subjected to the most stress In addition we maintain our own stan dards What are the future possibilitles for the rope pump The outlook Is good for the rope pump in the coming years It has quite a prosperous future among the poor Even if all the rural communities obtain electrical power there are not going to be the economic conditions which would allow every one to buy electric pumps The rope pump has been constructed with this in mind and as long as there exists poor peo ple we will need to keep pace with the demand in addition to training our personnel to face this challenge 76 First part The challenge of popular technology Photo 11 Mass production of p
28. drainage trough slab and to install a pump which facilitates withdrawing water and protects the well Since there are many wells there is a need for many pumps therefore the pump should be inexpensive and since there are few users for each pump it doesn t need to 38 First part The challenge of popular technology be made so strong Many wells are private and so a sales pol icy must be developed to impact these families whether with subsidies or not which once again implies an inexpensive pump both in construction and in maintenance The rope pump fulfills these requirements of price and simplici ty and is an ideal pump for such situations 2 2 Health Impacts There can be objections to the above approach by arguing that a drinking water source should guarantee 100 pure water the PAHO philosophy and that this cannot be achieved by improv ing existing wells with their faulty construction and poor loca tions Various studies have demonstrated that the quantity of water available has more effects on health than its quality An abundance of water stimulates its use to wash hands food dia pers the bathroom to clean the house etc Apparently these are more important sources of contamination than a certain de gree of contaminated water being consumed We don t want to say that one doesn t have to worry about drinking water quality but you do have to take into account that the quantity is more important The same studies
29. embedded in the slab The manhole serves to install and take apart the pump and to clean and deepen the well if necessary It should be located very close to the support to facilitate installation and taking apart the pump Its rim as well as the cover should be of concrete or iron iron is more expensive but more hermetic and given the greater heat also serves to repel insects etc The raising main with the rope inside comes out of the well through the anchor tube The rope crosses over the well slab going inside the well through the protection tube Both are made of PVC embed ded in the concrete slab The use of these tubes together with the rim of the manhole keeps contaminated water that falls on the well slab from entering the well The location of these two tubes should be precise in order to avoid the rope rubbing against the openings of the tubes The use and location of the base of the discharge spout are obvious Section 8 1explains the construction of the well slab Alternative constructions Although the model in this book has a concrete well slab as is common in rural water supply and sanitation projects the most common practice in Nicaragua is to leave the well exposed and to attach the pump to two wooden beams It is also common to have a well slab of planks The charactenstics of each option are demonstrated in table 6 1 Chapter 6 Description of the pump 91 Table 6 1 Advantages and disadvantages of three types
30. has yielded positive results We show samples to the people explaining the ad vantages and disadvantages We show them samples of wood and we provide other easier alternatives for making the guides and let them decide The rope pump is a technology developed here in Nicaragua Dem ster another type of hand pump comes from the U S and with the embargo who could find replacement parts during the war Yet al though there is no longer an embargo in effect it is difficult and ex pensive and access to parts can t be guaranteed in the countryside maybe in the city they are but not in the countryside Those that do the construction are the people the users with our help They support these rope pump projects because they are more accessible and less expensive According to our experience they have worked out well so far No one has come to us with complaints Instead they help us out and come to us for help in the construction of their own pumps 116 Second part Construction Chapter 7 Mechanical and hydraulic characteristics For easy and efficient operation it s important that the pump be designed according to the size of the user so that the hu man part of the task is easier This means that the physical strength of the user must be taken into account when calculat ing the relationship between the size of the pulley wheel crank and the force and power needed to operate the pump The study of this relationship
31. here in Nicaragua And as Nicaragua is a poor country the communities have few resources to be going about importing this or that part from abroad in order to keep the pump functioning The people say that this type of metal pump made from galvanized pipe draws up awful tasting water in the morning with foul sediment It takes about half an hour of pumping to clear the water that had remained in the tube while with the rope pump it even comes out colder Chapter 3 Rope pump characteristics 23 There is more acceptance of the rope pump seeing as how it is eas ier simpler and the accessories are well known It is so simple that it gets their attention and interests them because they see that they can do the installation and repiars and the costs aren t very high None of the community members or ranchers have requested those kinds of monstrous pumps They have shown a great interest in the rope pump and we have had a big demand for that type of pump not only from private individuals but from the communities with wells They haverejected the Indian or Demster type of pump because they have heard about the experiences of other communities with that kind of pump In order to not tell them what kind of system they should install we give them the various options but everyone has opted for the rope pump because they say that operating the pump is easier How well is the rope pump accepted by the users Concepci n There is a sayi
32. in the interior part of the mold is noticed After several hours the mold may be opened Leave them to dry several days before putting them into the kiln to fire As the walls are less thick the drying and the es cape of moisture is not as critical as in the case of the solid guides One alternative that could prove interesting but which we have not tested is that of using the same molds but leaving them solid instead of emptying them out E Specifications of the glazed ceramic guides am p rp Cut away area to protect the rubber inner tube from wear caused by the rope aes annn WI 7 SS 7 Z A Yi Yj Y Z Li a ndix Y RNN NNN Aaaa N Section A A _ 202 Solid guide for drilled well 203 E Specifications of the glazed ceramic guides Section B B Section A A l ooo i BALALBEE 7 SSS a d jd LY X 2 Q o 204 Appendix Appendix F Calculating pulley wheel and raising main diameters In section 7 2 we discussed the selection of the pulley wheel and raising main diameters so that the demand of force and power be adjusted to the optimal offer medium defined by the ergonomic parameters of the users In this appendix we deep en the discussion of the calculations regarding this topic Four categories of parameters enter into play in these calcula tion
33. in the successful transfer of technology is that which takes into account the subjects of development providing for their collective participation and unlimited creativity 18 First part The challenge of popular technology The introduction of glazed ceramic isolators in the wood guide was one Of the most important results of this first phase of con struction This allows the least wear on the rope and the pis tons overcoming the pump s most obvious weakness After about a year of pumping experience with various models and in novations the userinnovators decided that the rope pump is the most economical way to get water out of a well cheap er even than taking out water with rope and bucket Although not all changes in the pump s construction by the peasants were improvements it was very important to let the process develop at the community level The usefulness of the pump was proved by the way in which the communities appro priated the technology and slowly initiated the transfer to wards a large part of northwestern Nicaragua inciuding the ur ban area This experience generated enough confidence at the institution al level to program a directed and massive transfer supporting the community organization and education processes promot ing latent creativity and intellectual potential around a huge problem water The first step was to produce a community onrented flyer Oroz co E 1984 as well as to organi
34. is called ergonomics In this chapter we will first define the relevant ergonomic param eters then we will show how to choose the size of the wheel and raising main according to the depth of the well and finally we will see how these factors influence the efficiency of the pump In the text we will limit ourselves to presenting the mini mum amount of information necessary to understand these phe nomena and we give general instructions For the complete calculations we refer to Appendixes F and G 7 1 Ergonomic factors Below we explain the most relevant ergonomic factors We give estimated values according to practical experience and the available literature The determining factor in manua pumping is the available hu man power that is the force with which the user turns the pul ley wheel crank During a period of 1 to 5 minutes a child can generate approximately 40 watts while an aduit man can ee l Photo 18 so high In determining the proper height one must keep in mind not only the average height of the users but the height of the littlest as well El Pochote generate up to 150 watts Let s visualize these values a child who generates a force of 40 watts pumping a well that is 10 me ters deep will take a little longer than one minute to fill a 20 liter bucket An adult man who generates 150 watts can do the same in 20 seconds If on the other hand the well is 40 meters deep the child will have to pum
35. more strength was required and in the 20 meter deep well it was hard to turn The rope wasn t the problem the rope worked fine Of course the rope with that kind of pipe doesn t last as long be cause it has to work harder there s more tension When saw that the pulley wheel was ruined and had a serious problem brought someone to help Now with this 3 4 tube it works fine It would be good toput it in all the wells or in any well that has a lot of water We will discuss first the influence of the diameter of the raising main The force on the pulley wheel crank depends on the weight of the water column lifted by the rope It is as if the rope was lifting a very narrow and tall bucket the width of the raising main 120 Second part Construction and the length of the pumping head If the well is deep the force required to turn the crank is greater If the diameter of the raising main is large the force required is also greater This means that for a shallow well a bigger diameter raising main can be used for a deep well a smaller diameter tube is prefera ble A raising main with bigger diameter requires more effort but it yields a greater flow of water as well It is important to remember that by choosing a tube with a diameter for example fwo times greater the volume of water and therefore the effort as well increases by two multiplied by two or four times This is illus trated in the following graphic
36. ten years see figure 1 10 technified mode ae user built model a ow a gt T CL D 2 E m n en 3 3 a Figure 1 10 Rope pumps installed in Nicaragua Chapter 1 A developing technology 25 1 4 Implementation approaches After this short historical review we now analyze three proto types of rope pump implementation methodology with which we have experience in Nicaragua user building sales and institu tional water supply projects These prototypes are clearly rudi mentary and each initiative contains elements of all three Even so they are useful to analyze the achievements and limi tations of the different possibilities for technology implementa tion In each one we refer to the fundamentals that we detail in chapter 2 User built pumps The idea of user bduilt pumps is that the beneficiaries them selves build their own pump with available resources in some cases with institutional support This approach responds to the reality of many peasants who are not only farmers but are also carpenters masons etc In addition in the countryside there is often not cash available to buy a pump yet tools construction matenals Knowledge and time are available Wilian a promoter of user built pumps comments The most necessary tools for pump construction are a hammer a saw a square a ma chete is very important a hand drill to make some holes and a rasp The leather punch is nec
37. the tube and through if passes the rope and they don t put on any weights So there are problems Someone who had read Enlace installed a pump but then came later to ask me questions suppose he got it installed because he said that if he couldn t do t he would come get me but he never came What can be sald of the companies that Install great numbers of pumps For me it is very nice It s good for people who have cattle to have access to water But do ask myself f these people are training the users of these pumps in case they get damaged explain to the people as am installing This goes here and this goes there You ll put it together like this when it gets damaged Who knows if they are explaining to the user so that the pumps won t break down Do your procedures work have had no rejections of my methods nota one What happens Is one has to control the little ones who might want to fool around with the equipment So tell the children No no children This is not here to be fooled with Based on your experience what are the merits of the other pumps don t like them have seen the kind they use to fill the water troughs for cattle All of the system located down below ts difficult to take out and the water has a bad smell The rope pumps are more hygienic ard there s nothing to rust With the rope pump all you need is to have its rope and pistons ready while with the other one always has t
38. those who transmit that experience are the community and us And it is as a result of all these experiences direct or indirect that all the improvements are made in order to better the technology So feel that we are in fact in midst of the development of this new technology Chapter 3 Rope pump characteristics 57 3 2 Reliability In order to elaborate on the subject of reliability we will begin with its definition The definition of the reliability of equipment used most frequently is the Mean Time Before Failure MTBF However this definition does not take into account the time necessary for repairing the equipment and consequently it s inadequate for disperse potable water systems In this case corrective maintenance is a senous problem both in financial terms as well as time A different definition is used by Arlosoroff e a 1988 defining a pump s reliability in the following manner Reliability is what me chanical engineers call availability the probability that the equipment will be functioning on any given day calculating the functioning time as a percentage of the total time Functioning Time Reliability X 100 Total Time In this book we use the second definition The two definitions are illustrated in figure 31 Although pump B has a tendency to fail more frequently than pump A its reliability according to our definition is greater because repairs c
39. to show how easy it is to make the slab and in stall the pump Many of the activities described below can be done at the same time Clean the place where the slab will be pour it should be flat and preferably level Lay out the plastic Join the strip of sheet metal in a circle according to the diame ter of the well placing it on top of the plastic with the stakes or 136 Third part installation operation and management 137 Chapter 8 Installation in hand dug wells Well slab reinforcement 138 Third part Installation operation and management rocks inside Be careful not to cut your hands on the sheet met al Determine the position of the pump the outlet spout and the manhole see figures 8 1 and 8 2 Make the frame for the manhole nailing three 1 x 1 s ina U shape leaving the fourth side free to make it easier to lift the mold Make the rim frame for the manhole and the frame for the base of the outlet spout Make a flare on the protector tube a similar flare will also be made on the lower tube this is a more delicate task The flare is made by heating the end of the tube over fire and inserting the bottleneck It is important not to heat too much of the tube just the end or else the tube will get deformed and there will be a constriction see figure 8 3 that will interfere with the movement of the pistons You can avoid heating too much of Weill made flare Poorly m
40. tube cracking it as it went in and all of a sudden the tube split and the rope broke Test to see if the pistons pass through the guide and easily en ter through the flare into the raising pipe Temporarily tie the ends of the rope so they don t get lost in the tube Tie the stabilizing rock to the guide with galvanized wire Take the mold off the slab and place it on the rim of the well Be careful of your fingers Make sure the delivery tube sticks out 30 mm above the slab If it sticks out more cut it Roughen the inside top part where the wedge will go With an extra piece of raising main tube make a wedge as Chapter 8 Installation in hand dug wells 149 Photo 24 Poorly placed bearings The wide wing of the upper bearing half is incorrectly com pressed between the support and the ring welded to the axle Thus the lower bearing half has too much play and is coming loose We hope to have overcome this problem with the new de sign presented in Table 6 2 El Pochote shown in figure 8 6 Lower the combination of the stabilizing rock guide raising main and rope through the manhole making sure the raising main is correctly positioned and constantly checking that the rope is in the right place the raising main next to the delivery tube the rope loose and next to the protector tube If the well is deep or has a lot of water this positioning cannot be controlled or corrected once the tubing is lowered
41. user bullt rope pump Material Tool Mold amp Tools for Needs _Gauge Needs _ Needs Molds amp Slab Construction Carpentry Wood Tools 30 Wheel Wood 1 2 Carpentry GI tube Tools 30 Guide Fine wood Carpentry Tools 30 Old tires Knife fire Steel mold for Simple each piston metal lathe Tubing PVC Multiple Multiple complex Advanced extruders molds lathes and machines milling B Materials tools gauges and molds 189 Table A 1 Materials tools gauges and molds needed for the construction of a technifled rope pump Part Material Tool Needs Mold amp Gauge Tools for molds Needs Well Concrete Zinc for the outer mold 1 Carpentry and wood for construction toolsmanhole 3 Wheel Welded Wheel gauge 15 Electric Iron frame gauge 3 Welder optional both 110 V50A of welded iron Guide Glazed 1 3009 oven Carpentry Ceramic 3 500 tools cinvaram kneader110V 2 500 not essential ceramic tools PE PP in One mold of steel Simple lathe granules extruder110V jor bronze metal 60 Tubing PVC Multiple Multiple complex Advanced extruders molds lathes and milling machines 190 Appendix C Materials for the pulley wheel in hand dug wells Part Wheel handle Bushing Axle Superior beanng Inferior bearing Bearing block pin security bolt U support f bearing Protection 10 Support f protection 11 Pulley 12 Pulley support 13 Brake pin
42. water between the rope and the pulley wheel the guide and the water and in the bearings By maintaining the bearings well greased there s not much that can be done to improve this aspect these frictions are low and inevitable It is difficult to accurately measure mechanical effi ciency but on the basis of practical experience we estimate it at 80 90 Hydraulic efficiency consists of the water leakage from the Narrow gap that inevitably exists between the piston and the wall of the raising main In other words it is the difference be tween the speed of the water column and the speed of the rope and pistons This efficiency level is easy to measure and prac tical tests demonstrate that it varies between 80 and 95 Hy draulic efficiency depends on varous production fac tors especially the play of the pistons and their speed To understand more about the influence of each factor the DAR Region V developed a theoretical model that was tested in 53 practical tests See annex G The influence of the different fac tors on hydraulic efficiency is reflected in figures 7 1 7 3 Next we introduce the factors that have a bearing on hydraulic efficiency in descending order of importance the gap between the pistons and the raising main tube the speed of the pistons the distance between pistons and lastly the diameter of the raising main tube The most important factor and the most difficult to optimize
43. we prefer to vary the diameter of the raising main tube leaving the pulley wheel the same The other option would be to vary the pulley wheel leaving the tube diameter the same We don t have much expenence with this alternative mainly for fear of wearing out both the rope and the pulley whee due to the great concen tration of stresses that would be required However this option could be advantageous when the variations in the pumping head are relatively small 122 Second part Construction Table 7 2 Advantages and disadvantages of varying the diameter of the raising maln vs the diameter of the pulley wheel Vary raising main tube diameter maintain pulley whee diameter fixed Standardization of wheels 1 range of pipes and pistons Implies greater initial investment molds for pistons and greater diversification of PVC accesories and pistons 15 accesories Relatively low costs for deep wells due to small diameter tubing Maximum piston assures high efficiency speed Force exerted on blocking system tension on rope and intensity of friction between rope and pulley wheel do not significantly vary with well depth Maintain ralsing main tube diameter Vary pulley wheel diameter Standardization of PVC accesories and pistons 6 accesories range of 5 wheels Getting enough tires of different sizes may be difficult Costs go up according to well depth Slower piston speed at great depth i
44. what is allowable see annex F for calculations This implies that spe cial pistons have to be made along with a guide and extra large stabilizing rock Since this model has no blocking system the construction of the wheel is very simple the pulley runs be tween two bearings of the normal design Nevertheless the force is greater and we reccomend the use of 3 4 iron for the feet 3 8 for the spokes with an axle 3 4 13 The literature for example Lambert et al 1990 mentions models with raising mains up to 3 or 4 It also indicates the pos sibility of installing an inclined pump to pump from lagoons and Canals 178 Fourth part Special Models scope of model The limitations are due to the power that the operators are able to achieve pumping a well dry with two teams of two men each we have reached volumes of 2 L s at 10 meters of pumping head but at lower heads higher volumes are sustainable for a long time In principle there are no limits on maximum depth always assuming that the optimal raising main diameter is cho sen according to available power Experiences and development There are now various years of experience with these models and since the differences with the normal pump are minimal we do not feel that there is any limitation in terms of their large scale implementation Neither do we consider it necessary to go into greater depth concerning their construction and installa tion Chapter 14
45. years the intensive use of the pump can weak en and even break the welding of the spokes The rope along with the effect of the sun will eventually damage the rubber of 156 Third part Installation operation and management the pulley wheel Materials needed new wheel a small amount of grease fixed or adjustable wrench In this chapter we discussed maintenance planning and the nec essary tasks to keep the pump in good working order In the next chapter we will analyze some of the most common prob lems and their solutions troubleshooting Chapter 10 Troubleshooting 157 Chapter 10 Troubleshooting In the last chapter of this section we will look at some of the most common problems that occur during installation operation and maintenance We ll describe the symptoms the possible causes and possible solutions Both the problems and their possible causes are listed in descending order of probability g a ro a he one rt ms OE ee z EES 3 ae ae P a Fa E dean T S a IOT stet AT p F PEE 1 4m Ee Se Fr TA 35 ta pe pj neat t rmt E RE E awar tl j A Ai Photo 25 Broken water raising main in the foreground ot this photo is clearly seen the stabilizing stone fastened by a rubber tire to the glazed ceramic guide The upper tube is the protection tube the lower tube which is the water rais ing main has moved downward and the rope has cracked it The pistons catch within the
46. 00 v al sur Managua Henk Holtslag 505 2 74952 Name Description Address Name Description Contact Address Tel Fax Name Description Contact Address Tel Fax Jose Evaristo Talavera Micro workshop of PE and PP injected pistons Frente al antiguo Mercado Periferico Managua Palo de Hule Foundation of social projects in the town of Nueva Guinea founded in 1990 Car ries out minisocial projects and own a shop of sanitation and other materials to improve wells including rope pumps Donald Rios Frente a la alcaldia municipal Nueva Guinea via DAR Region V 505 81 351 740 via DAR Region V 505 81 369 505 2 763205 Puente de Paz US solidarity organization Finances and executes small development projects Works with rope pumps at the level of lo cal construction William Torrez promoter Dorie Barg mann adviser Colonla Centroamerica 441 Managua 505 2 7 350 via CEPAD 505 2 664236 224 Name Description Address Name Description Contact Address Tel Appendix Rafael Castilla Castro Metailurgic workshop with 3 workers who have been involved in the development of appropriate technology projects since 1984 Produce wheels for rope pumps of different types Del INAA 1 2 c al sur 1 2 c dragiba Juigalpa Society for the selling and Installation of rope pumps Founded in mid 1990 thi
47. 1 Rope pump in drilled wells Issues involved Although the majority of wells used for drinking water are hand dug machine and hand drilled wells are also frequently found In the context of this book the only difference between the two is depth hand drilled wells are generally less than 20 meters deep while machine dnilled wells are usually over 60 meters In order to not complicate the terminology too much we use the term drilled wells since most of what we describe can be ap plied to both machine and hand dnilled wells It is easy to adapt a rope pump for use in a drilled well It is also possible to eventually run the pump using an electric or combus tion motor to pump very deep water Scope of Model Rope pumps are currently being used in drilled wells with a minimum diameter of 4 with pumping heads of some 40 me ters It seems that even greater depths are feasible although they haven t been tested The model described here with two handles supplies 8 cubic meters of water per day Experiences and perspectives In various places pumps have been used on drilled wells with out serious problems The reason that this model pump is not more widely known than the four or five models that are current ly in operation is simply a lack of demand The model described in the study of Pochote has worked well under severe conditions for 9 months without major problems The DAR Region V is 166 Fourth part Spe
48. 1 Reliability of two pumps 58 Figure 3 2 Pumping discharge rates 60 Figure 3 3 Hydraulic efficiency 63 Figure 3 4 Well contamination 64 Figure 3 5 Price structures 67 Figure 3 6 Prices of different pumps 70 Figure 6 1 Figure 6 2 Figure 6 3 Figure 6 4 Figure 6 5 Figure 6 6 Figure 6 7 Figure 6 8 Figure 7 1 Figure 7 2 Figure 7 3 Figure 8 1 Figure 8 2 Figure 8 3 Figure 8 4 Figure 8 5 Figure 8 6 Figure 8 7 Figure 8 8 Figure 11 1 Complete pump Concrete well siab The iron wheel How to cut an old tire Forces acting on pistons vs washers Vanation of tube diameters Creation of the vacuum Conjunction of guide for hand drilled wells Hydraulic efficiency as a function of gap Hydraulic efficiency as a function of piston velocity Hydraulic efficiency Slab measurements Frame slab Restriction in the flare How to secure the piston to the rope Conjunction of guide for hand dug wells How to make the wedge Outlet spout Bearing conjunction Stabilizing stone for a drilled well Figure 12 2 Outlet tubing options for pump on a post Figure A 1 Figure A 2 Figure A 3 Figure A 4 Figure A 5 Figure A 6 Figure A 7 Figure A 8 Figure A 9 Technical drawing pulley wheel Technical drawing bearings Technical drawing blocking system Gauges for injected pistons Technical drawing solid guide for hand dug wells Technical drawing solid gu
49. 6 First part The challenge of popular technology This pump is installed over a drilled well with a 35 meter pumping head It yields 32 barrels 8 cubic meters a day El Pochote possible long term transfer and development leaving the initia tive to those who knew the area best the local population In less than a month spontaneous self construction and innova tion projects began in the community CITA s participation con sisted of promoting the organization of the community into two collectives in order to satisfy the need for pumps in the commu nity and to enrich the innovation process encouraging interac tion and solidarity among the peasant inventors There was also institutional support with the supply at cost of PVC tubes the experimental distribution of prefabricated rubber pistons and the training of peasant inventors in theoretical aspects of technology Chapter 1 A developing technology 17 Nemesio Porras Mendieta What In your opinion might be the rope pump s formula for success In analyzing its objectives the uses it fulfills and its implications for the rural sector there are direct and indirect benefits As of now the opinions regarding this point vary in the extreme either over wheiming enthusiasm or attributing its achievements to the devil The enthusiasts are clear about its popular nature its revolutionary undertones as a result of the organization it requires its promoting the participati
50. 7 2 we discussed the selection of the pulley and raising main diameters so that the demand of force and power be adjusted to the optical offer medium defined by the ergonomic parameters of the users In this appendix we deepen the discussion of the calculations regarding this topic Four categories of parameters enter into play in these calculations the ergonomic parameters the invariable parameters the variable factor that we cannot influence the pumping head and thus the two variable parameters that we have at our disposition for optimizing the system the pulley and raising main diameters The ergonomic parameters are fixed ranges that we cannot influence They are the following kr r Rope Pump _ _ SSS o 9 hana Pump wheel handle diameter 500 mm Fhante Force on the pump handle between 50 N and 120 N Pin Input power developed by user varies from 40 W to 150 W f Frequency of axis revolution of the pump handle with a range of 0 7 1 revolution per second The invariable parameters that influence the calculation of forces are g Acceleration of gravity 9 81 m s2 moc Mechanical efficiency estimated at 0 8 O wpe Rope diameter 5 mm HI 3 1416 O Specific weight of water 1 000 kg m3 The variable factor that we cannot influence but which does guide we selection of the diameters is Hneas Pumping head m The two parameters that we can vary tooptimize the system are Dou Eff
51. 9 mm should read uo 71 mm D ps 69 mm Page 225 paragraph 2 line 6 Oude Velperweg 506824 HE Arnhem should read Oude Veiperweg 50 6824 HE Arnhem List of Symbols page 217 f S 11 F handie N Frandio texr N g ms Hneaa M Hos m O mm Dandie MM Diope mm mm mm mm Pa W Pa W m s ms m s m s Qter m s Vos m s g mm Qiss Qrea Frecuency of axis revolutions 0 6 1 Real force on pump handle Fhandie teor mec Force on pump handle if there were no friction Gravity acceleration Pumping head Distance between pistons Diameter Pump handle diameter 500 Rope diameter 5 Piston diameter 18 44 Pulley diameter 350 540 Raising main diameter 18 2 44 5 Input power developed by user 30 150 Output power resulting in pumped water Component of loss flow due to drag by piston Loss flow Qros Q drag Component of loss flow due to pressure Real flow Theoretical flow Piston speed Theoretical volume per rotation Play between piston and tube Q w oe 9 81 2 4 0 2 1 4 ERRATA n Pump total efficiency nya Mmec Nhya Hydraulic efficiency Q rea Q tor 80 95 Nmoc Mechanical efficiency defined as loss factor due to friction F handle toor F handie 80 90 Il Pi 3 1416 O Kg m Specific weight of water 1 000 v ms Kinematic viscosity of water 1 10 Appendix F Calculating pulley and raising main diameters page 204 In paragraph
52. Although the great majority of the discharge spouts are made of PVC there are some made of galvanized Iron 7 In Guatemala the discharge spout has been replaced in some experiments with a cement chamber called a flare It seems to work well but as all other forms it requires a PVC raising main We do not see much advantage in using this other construction method with a great work investment for a piece that can be made with the same standard PVC tubing Chapter 6 Description of the pump 113 Table 6 9 Advantages and disadvantages of the PVC and GI discharge spouts Resistance to vandalism Installation ease Life duration 4 years 15 years Price of a 1 pipe 1 20 8 40 Price of a 1 1 2 pipe 2 40 12 50 Production level National National Years of field experience 8 years 3 years Note that this is more than the useful life that we attribute to the support structure 10 years Alternative 2 The use of galvanized iron pipes in the discharge spouts to guarantee greater protection against vandalism is on lyvalid when the rope also is well protected given that this is the piece most vulnerable to vandalism lts installation requires plumbing tools pipe cutters adjustable wrenches for pipes in this chapter we have discussed the different construction al ternatives for all of the elements of the pump the well slab pul ley wheel pistons rope tubing and guide In the following chapter we will se
53. E AXLE p 92 In Nueva Guinea we have the experience that the axle regurarly breaks where it is bended Reasons Small radius Bad quality of the bendings see photo 23 Suggestions e Make the bends with bigger radius e Make the bends of 120 instead of 90 degrees 120 this is easier if pulley wheel is mounted between supports e Bend the pipe with adequate tools for instance a tool like in the illustration Pumps made like this 3 years ago and bend with this tool had no problems Diameter of pipe 1 mn length of half Plpediameter 2mm Plate of 3 16 gt with radius of 2 THE BEARINGS p 147 149 60 mm Of the mayority of the pumps of this design the bearings are getting loose for example like on page 149 or the bearings got lost causing worn out and breaking axles Reasons e Some pumps were installed with a pin instead of a safety bolt e The safety bolt got lost or got removed and a small pin was placed In this way the upper bearing gets loose and after that the lower bearing RATA Rope Pump 3 e incorrectly installed bearings see p 149 e Lack of knowledge maintenance and back up of the water committees and the users Suggestions If design of page 147 is used weld the lower bearings with some points if it is felt neccesary that axle and pulley wheel should be removable the experience is that the bearings and the axle hardly wear out when th
54. Keep a certain tension on the loose rope so it doesn t get tangled with the guide or the Stabilizing rock Cut plane and glue the two outlet spout tubes the elbow con nector the T connector and the tube reducer See figure 8 7 Untie the temporary knot pass the rope through the delivery 150 Third part Installation operation and management tube and the protector tube using wire and through the outlet spout Make another temporary knot Insert the raising main into the protector tube and cut it at least 30 mm above the tube s end Be careful not to cut the rope Inside the well the raising main should be straight and vertical not sagging or warped but the stabilizing rock should rest at the bottom Plane the end of the tube and roughen the part that will be pressed tight by the wedge See figures 8 6 and 8 7 It is important that the wedge be made in Such a way so that it will exert even pressure on the raising main See chapter 10 problem 1 Secure the raising main tube to the delivery tube inserting the wedge Gently hammer the wedge Join the outlet spout tube reducer to the raising main tube and bend the anchors to secure the outlet spout It is very important to not use glue on the wedge or on the joint between the raising main and the outlet spout as this will make it impossible to take the pump apart Make a good knot without tensing the rope but leaving 100 200 mm play Cut the rope leavi
55. Motor driven rope pumps Issues Involved We have mentioned several times the greatest restriction in the application of special models the limited human power and en ergy available The motorized rope pump overcomes this limita tion which in principle expands its application to irrigation pumping wells dry fill tanks on platforms pump water from great depths etc This broader application significantly increas s the possibilities of what the rope pump can cover Description of the model A combustion or electric motor works with a small pulley wheel of 12 through a reducer a v belt with a small pulley of 12 and a large 20 pulley The greater rotating speeds of the axes im pede the use of the simple bearings described in this book we reccomend wooden bronze or ball bearings Scope of model There is not sufficient experience to define with precision the scope of this model pumping can be done with a 2 5 kw motor for example 12 m3 hour from a depth of 12 meters or 4 5 m3 hour from a depth of 40 meters Experlences and development No pump of this model has been functioning for more than sev eral months and thus we cannot say much about its behavior in the medium and long term nor about possible construction problems related with phenomena such as fatigue etc To date 180 Fourth part Special Models we do not have experiences with more than 2 5 kw of power but nothing indicates that a more powerful mo
56. Qloss Q pres Qdrag m3 s 3 F Calculating hydraulic efficiency 211 In order to calcu late Qloss we de fine three pres sure factors PO P1 and p2 See figure A 9 The PO fall in pressure PO P1 is due to friction losses on the ring while the p drop in pressure P1 P2 is pro voked by exit losses The mod al analyzes each Figure A 10 Principal parameters that Influence A ee e B piston as if it Were lihe calculation model for hydraulic etficiency of independent that the rope pump is they all demon Strate the same loss It also does not take into account en trance and exit effects Thus PO P2 corresponds to the pressure on the water column between two pistons 14 WHI VOOM ww DE P1 SY Ws WY en A PO P2 PO P1 P1 P2 9 gHpis N m2 4 Now that we have defined the pressure that is exercised on dif ferent parts Note that the value of P1 is unknown we can give the formulas to calculate the two flows Qdrag and Qpres with out entering into flow study theory 14 Not taken into account are the dynamic effect of water flow such as the acceleration of water and the friction between the water and the tube This is acceptable because it represents less than 1 in our conditions 212 Appendix 2 Bois 2 2n Po Pi Dnb y Smart i Ga Qaan a tub Ors Qurag 2 Din Ds m3 s 6 The remaining component is that of the exit l
57. a ram with gauge for the guide Introduction This book just like the rope pump is imperfect And just like the rope pump it is too important to wait for its perfection We have just left the decade which took on the challenge to re solve at the very least the problem of water for human con sumption supposedly combining efforts of all the nations of the world with their technologies But despite good intentions and million dollar investments the majority of the world s population continues to face an infant mortality rate and a senes of illness es which if it had sufficient water available would not exist in such quantities Even more in absolute numbers there are more people who do not have access to basic water and sanita tion services than at the beginning of the decade The search for appropriate technologies continues to be an urgent chal lenge available to all inexpensive but efficient easily built op erated and maintained Many individual and institutional initiatives over the last eight years have developed and promoted the rope pump in Nicara gua under different concepts designs and implementation ap proaches as one alternative technology Development has been primarily directed towards the drinking water supply from hand dug wells from 5 to 20 meters The pump has been so successful at the national level that we believe the moment has arrived to put the Nicaraguan experiences in writing The initia tive an
58. a tional water utility INAA in Region V With its 60 employees it is dedicated to rural water supply and sanitation pro grams and education It began using the rope pump in 1988 and has worked in its development particularly in terms of the design of the wheel and in rope pumps used with drilled wells It took the initia tive to make thispublication a reality Osmundo Solis Orozco head of commu nity participation Contiguo al BND Juigalpa Apartado Postal 24 Juigalpa 505 81 351 740 505 81 369 505 2 763205 Name Description Contact Address Tel Name Description Contact Address Name Description Contact Address Tel Appendix Guadalupe Carney Cooperative Women s cooperative producing among other things molded glazed ceramic guides Ervin Torrez manager Ron Rivera ad viser De la Normal 200 m al Norte Estell Ron Rivera 505 2 73807 HUTECNIC Rubber PP PE PVC etc injection workshop Has worked making pistons since 1985 Celimo Morales Novoa owner manager Puente Larreynaga 2 c abajo 25 v al norte Managua Ignacio Lopez Workshop Private metallurgic workshop that has produced wheels for different models since 1990 Working on developing a motorized rope pump as well as a rope pump that works with a windmill ignacio Lopez and Reynaldo Erlach partners Henk Holtsiag windmill development De los semaforos Repuestos La 15 1
59. a have a pulley wheel between the two bearings Although this construction is not bad in itself we think that it does not present any advantage over the design presented in this book See table 6 4 In alternative 2 the bearing of the pulley wheel handle is the only one that is rigid in the direction of the axle Protection for the pulley wheel To protect the rope and the pulley wheel from the sun dirty hands and possible flies various alternatives exist Until now none could be implemented on a large scale mostly because the users do not give them priority Table 6 5 Advantages and disadvantages of four types of protection systems _ pe Fores Water Protection Protection against vandalism Protection of rope Protection against insect nests Esthetics Acceptance by users Price Level of production Years of field experience The first price takes into account the purchase of wood at market price the second does not take into account the value of the wood 102 Second part Construction 6 4 Pistons rope and raising main The rope within the pistons is 3 to 6 mm in diameter generally 5 independent of the raising main s diameter and the depth at least up to 40 meters It is made of PE fibers and with three strands It is a very common rope and can easily be made by any artisan although good quality guarantees a longer useful life The rope is the piece of the pump that wears out the most see se
60. ade flare Figure 8 3 Restriction In the flare Chapter 8 Installation in hand dug wells 139 the tube by wrapping the tube in wet rags or newspapers leav ing only the end for the flare exposed Roughen the outside lower 100 mm of the protector tube and of the PVC delivery tube that will be embedded in the concrete The protector tube goes with the flare facing up so that the rope and pistons can enter easily Cut the iron rod and brace the frame The distance between rods should be 150 200 mm See figure 8 2 Position the pump support placing it in such a way so that the iron rods don t interfere with the correct positioning of the delivery tube and pro tector tube lt is important to position these two tubes exactly underneath the pulley wheel using the plumb bob If they are not positioned Y Tria af iha moie Sia oe Photo 22 Incorrect placement of the pretection tube This protection tube has no flare and is badly placed the rope and in particular the knots and pistons rub against the tube and in a few months will be worn out 140 Third part Installation operation and management correctly or if they are not exactly vertical the rope will rub against the tubes and will wear out very quickly see photo When they are correctly positioned fasten the support to the frame and the tubes to their respective guides in the wheel and if possible to the frame as well Cut positio
61. ake any sense to install a pump that hermetically seals such wells Finally many rope pumps in Nicaragua are installed in wells without a slab or a wooden cover Although it is true that in these cases the well s protection is not as good as with a con crete slab even in these cases the pump s installation means a substantial improvement in the hygenic conditions of the benefi cianles because the ease with which users can take out water encourages them to use greater quantities See paragrah 2 2 Impacting health Chapter 3 Rope pump characteristics 67 3 5 Costs The rope pump is very inexpensive the price of the technified model varies between 43 to 47 according to depth while the user built pump costs about 13 This price does not include the cost of the wooden wheel The market price of this wood would be between 8 to 10 but practice demonstrates that old pieces of wood are almost always used a es a Technified model _ User bunlt model 47 438 455 30 m NANNY MOO Price 20 m 10 m Pumping head m Figure 3 5 Price Structure The price structure of the technified rope pump and of the user built according to the pumping head Source author and Barg mann D 1991 For an investment program for rural water supply and sanitation projects this data is not significant the pump s cost is a mini mum percentage of the total project cost The other characteris tics of t
62. al There is also a limit ed network of pump parts sales Even with these conditions the majority of the pumps are in good condition illustrating that the rope pump can be maintained perfectly well by the users as long as they have been given adequate training Chapter 2 Basic rope pump concepts 43 2 6 Local manufacture Literature mentions advantages of local production of hand pumps which include saving money greater probability of parts availability knowledge to make repairs and finally stimulation of local industry Disadvantages mentioned in these studies are design limitations because of low technological lev eis and problems of quality control Clearly the rope pump concept is one of local pro duction as much as possible The arguments are generally the same as those mentioned above but it is worth go ing Into detail in some areas Selft sufficiency In order to reach Photo 9 Local production the above The iron worker Rafael Castilla with a sup mentioned goal of ply of structural supports in his workshop self sufficiency where he makes among other things pulley a heels for the ro mps Juigalpa existing local pro wheels for the rope pumps Juigalpa 44 First part The challenge of popular technology duction structures should be involved This small local industry can be supported in its growth by introducing new techniques and tools this is part of the development process
63. alls and emphasis is put on the pump s force rather than on its cost Water quality protection is also prioritized Within this approachy impacts on health local operation and maintenance and national production are prioritized It is warth referring to a combination of institutional projects with private sales the DAR Region V initiative offers the sale of con struction matenals rope pumps technical assistance and sani tary education at a reasonable price This initiative was de scribed in the above paragraph and in the interview with Alfonso Arag n One of the advantages of this method is the greater possibility of impacting the living conditions of the community because of the Integration of the activities There are usually resources and willingness to contribute to the study of the pump and the production of information and documentation The greatest danger is that of working too schematically and not responding to the specific needs of the beneficiaries which results in lack of interest on their part Another limitation is that these projects are limited to specific areas and many times to specific groups within those areas Up to here we have the description of the three most developed implementation approaches in Nicaragua As can be observed each one has strong and weak points and the reader will have to decide which is most convenient for each situation and objec tive In chapter 2 we pull from these practical experien
64. an be made more rap idly itis not necessary to bring tools parts or technicians from a long distance and all repairs can be made locally The rope pump is a typical example of pump type B itis not very rugged but repairs are easy and fast The only aspect to worry about Is the transference of technology to users and the distribution of parts 58 First part The challenge of popular technology Pump A Pump B MTBF 9 monthe Figure 3 1 Reliability of two pumps A ficticious chronogram of the functioning of the two pumps Given the definition used_in this book pump B is more reliable than pump A The rope pump is a typical example of pump B Reliability within the definition used here 1s not just a technical matter socio economic and cultural factors also come into play for example motivation of users to take action to repair the pump the possibility of taking water out of the well even if the pump Is broken l availability and quality of alternative water sources complexity of repairs costs and availability of necessary parts level of training and self confidence of users Here tt will be demonstrated whether or not training was effective for the prin cipal users women to maintain the pump or if it was only effec tive for those who dug the well men Chapter 3 Rope pump characteristics 59 All of these factors are important points that should be consid ered in institutional rural water su
65. antages and disadvantages of three types of bearings 1 3 Split Fixed bearings i bearings welded Fig A 2 Ease of replacing axle bearings Ease of construction Initial price of bearing conjunction Price to change bearing Years of field experience Alternative 2 We have confirmed that the users have difficulty mounting these bearings A lot of attention must be paid to this during training This is why we began to design bearings of type 1 As the promoter Humberto comments regarding the bearings With these 12 pumps one was damaged by the bearings The kids lose them because the bearings are a little mobile and so this has meant that they get lost The pump con tinues to turn but the pulley wheel handles gets worn out Chapter 6 Description of the pump 99 Blockage system Only in the case of shallow wells or of adult or experienced us ers can the discarding of the blockage system be contemplated In all the other cases it must be considered as an important se curity system A type of construction that can compete with the design in this book is the pawl shown in the photo See table Table 6 3 Advantages and Table ga Advantages and disadvantagos of the two Table ga Advantages and disadvantagos wheel locations Rigidity of the support Maximum force on the bearing of the pulley wheel 3 3 Maximum force on the bearings of the handle 4 3 Ease for installing the pump Years of field experience
66. be made in many ways and with many materi als 5 according to the necessity for high efficiency and the possibilities of production We present here the most common alternatives with their appraisal if this data exists Table 6 7 Advantages and disadvantages of four _ of pon PE o or PP Soft PVC Wood Rubber cut injected Optimumform Precision minimal play Resistance to wear Maximum depth Proven m 40 m Unit Price 0 77 Production level regional Years field experience 6 yrs 2 yrs Alternative 1 The technical specifications of these pistons are given in Appendix D Alternative 2 In reality we have not had significant field experi ence with these pistons Alternative 3 These pistons can be made with a simple wood 5 There Is little difference in the mechanical characteristics between these two materials both serve as material for the pistons 108 Second part Construction lathe The wood should be hard fine and water resistant Preferably it should have resin to serve as a lubricant 6 Some types ust in Nicaragua are in descending order ambara Granadilla Algergia Retusa Cortez Tabebuia Guyacan Gua pinol Hymenaea Courbaril Coyote Loncho Cartus Latifolius Alternative 4 Rubber from an old tire can be used preferably between 8 12 mm thickness or from a bought rubber sheet The punch should have its point of machibed steel with an in terior diameter that mea
67. between the piston and the raising main 1 2 tube 2m distance between pistons Source Heuthorst 1991 When referring to the pump s efficiency rate the subject of er gonomics must be mentioned the ease of movement or the user efficiency ft is known that an easy movement to drive the pump permits the user to generate more power and become less tired The uniform circular movement of the pulley wheel handle is in this respect much more favorable than the move ment of tilting a lever These are not just the criteria of users in Nicaragua but also the conclusions of field and laboratory tests done in Ariosoroff e a 1988 64 First part The challenge of popular technology This ascect could be improved somewhat by including a fly wheel cr the pulley wheel an element to consider for very deep wells or high discharge rates We thus conclude that in terms of efficiency rates the rope pump complies completely with the requirements 3 4 Water quality protection One of the principal reasons for installing manual pumps is to protect the quality of drinking water in the well the pump seals the well and impedes the infiltration of contaminated water Al though t is true that the rope pump does not seal the well her meticallly think about the rope and the openings of the protec tion tubes it has been proven to give ample protection The concrete slab with the protective tubes makes the infiltration of contaminated wat
68. blocks in case one has to make a rim for their well or an apron all those things We have everything We ve also poured concrete floors in the houses of some poor people In the majority of the wells in which we have installed pumps about 60 we have done all of the work necessary including the rim the apron all the work even the storage tank for collecting the water That s something that we include in the installation and sell in the store When people saw the first pump installed and functioning the rest of the people began to arrive at the store to see how they could get their own pump How do you train people in the use of the pump The training of the users is 100 complete It only takes a short time to install the pump about an hour and a half But in some cases for example when have to install two pumps in one day dedicate all my time in order that the people learn well When possible we install the pump once see how it functions and then sometimes take it out again and tell the users to install it Chapter 1 A developing technology 31 themselves so they begin with the first steps and finish the job well In four months have installed 64 pumps and they are still functioning During my first month of work installed 11 pumps And honestly did the rest in just these four months of work There are 200 requests pending is It necessary to visit the sites to see how the pumps are functioni
69. but it also has a cost Creation of the vacuum 106 Second part Construction any imperfection in the tubing obstructs the pistons An imper fection could be any fissure in the tube for example in the flare a shock received or dirt Particuarly if the pumping head is less it makes sense to opt for a greater play up to 1 mm to avoid these problems In section 7 3 we study the effect of play on efficiency For an illustration see table 6 6 for the measures for pistons and the raising main used in the DAR Region V More important than the minimal play between the piston and the tube is the uniformity of the measures of the pistons If they are not uniform the leak in one piston will be much less than in the others and only some pistons will work figure 6 7 If a pis ton comes out tightly an implosion will be heard given the vacu um created below it This phenomenon not only negatively aft fects efficiency but provokes greater and more itregular forces in the rope and tubing This becomes a danger particularly when the pistons are made and corrected by hand and at great er depths No de Ident Average interior diameter Otub mm Piston diameter Opis mm Play mm Diameter of discharge spout Depth aptitude m This data is from pistons and used tubes by the DAR Region V This table Is just an illustration not for directions Chapter 6 Description of the pump 107 Alternative constructions The pistons can
70. c supervision in relation to the rope pump Concepcion The degree of contamination is not a function of the pump or the type of pump one installs in the well It stems from the users because no matter how well covered or hermetically sealed a well might be if the user doesn t know how to manage the pump or doesn t know how to make proper use or the water if there has exist ed no ongoing education regarding sanitation there tends to be con tamination even if they are using a rope pump Humberto There isn t a need for much public supervision because the community appreciates a pump of this type it hasbeen noted in the communities that it is as though they have more love for a pump of this type as though they were seeing it as being weaker For this reason they themselves take more care than they would with the other pump with which they might even see if they could hook it up to an ox But they feel that it is competent and so they take better care of that little pump or show it more love you might say Who decides on what type of pump to use and what lies In store for the future Humberto The communities themselves have shown us that the pump that works for them is the rope pump We can t install some thing that tomorrow will leave the community with the same problem as before they have no way of drawing the water they begin to put 56 First part The challenge of popular technology their containers inside the w
71. ce costs in dollars per month Technified Pump User built Pump Discharge Depth m Discharge ms day 10 20 30 ma day 1 09 1 93 2 76 1 09 0 92 1 09 1 46 0 91 1 08 0 850 93 1 04 0 86 1 04 The table indicates maintenance costs in dollars per month factory sale price for two cases technified and user buil according to differing conditions for use Note that the difference in maintenance costs in both cases is minimal Calculation Appendix A The tools necessary to change the rope pistons and guide are limited to a knife and a burning ember To change the bear ings a no 10 wrench is needed A saw and PVC glue are re quired to change the pipes As regards personnel required for maintenance the qualifica tions necessary in order to do upkeep are minimal and after a half day of training anyone can do maintenance The rope and the pistons can be changed in half an hour the majority of this time is occupied in fastening the pistons on the rope while it only takes 15 minutes to take out the pump In the case of the user built pumps where rubber pistons and wooden guides are used all the parts can be made in the com munity In the case of technified pumps PE pistons and glazed ceramic guides are used so it is necessary to create a system Chapter 3 Rope pump characteristics 51 Table 3 2 Useful life for pump pieces by month Technified User built glazed ceramic guide wooden gui
72. ces vari ous fundamentals which are at the base of the rope pump 34 First part The challenge of popular technology Chapter 2 Basic rope pump concepts Different ways of analyzing a problem result in different techno logical solutions Behind every technology exists or existed originally certain basic concepts There was some vision whether conscious or unconscious although it may have been lost during the technology s evolution In this chapter we try to make concrete some of the concepts which are at the base of the rope pump as a low cost popular technology a felt need by the beneficiaries health impacts self sufficiency social control village level operation and mangement local manufacture technology transfer technical theoretical concepts In the above section where we described different approaches for implementing the rope pump we implicitly knew these basic concepts The basic concepts do not only refer to the approach of the in troduction of the pump but also to the apparatus itself The as pects are two sides of the same coin the introduction of a tech nology with community benefits They are inseparable The basic concept of the rope pump is known as appropriate technology In literature about technological development of so called third world countries the concept of appropriate technology has played a fundamental and increasingly impor tant role
73. change these priorities but for now this is the basis for action And if we want the bene ficianes themselves to plan carry out and maintain their own water supply system we have to offer them something that is important to them and not grasp on to some established plan for example PAHO norms INAA standards etc Once the improvements have been made and enjoyed the ben eficiaries will modify their critena and see the importance of oth er improvements We propose a process of step by step improvements assimilated one by one by the users in stead of imposing a pre designed sanitation system Let s keep these considerations in mind while we analyze the drinking water situation in rural areas It is relatively easy to dig wells in many zones water depth ranges between 5 and 30 me ters and the soil is not very rocky There are villages where half the houses have wells and the other half buy their water from these wells In these cases it is ridiculous to tell acommunity to build one or two community wells because the people will not be interested We have to remember their list of priorities Another typical situation in rural areas is very dispersed commu nities extending for kilometers with micro nuclei of 4 or 5 hous es A single central well would also not be much use because it does not fit in with their priorities In situations like these it makes more sense to improve the ex isting wells to build the well s apron a
74. chnology as something finished On the contrary it presents this alternative as one step in the generation of always more adequate solu tions In this sense we feel it is important to present some his toric elements which help to see the logic and the limitations of the development of this technology Since the discovery long ago of water s influence on plant growth to today when man is able to program genetic changes in those same plants the problem of controlling and bringing this vital liquid to necessary level has motivated a combination of the most varied experiences abilities and knowledge over thousands of years Chapter 1 A developing technology 9 Figure 1 1 Shaduf Figure 1 2 Norlia The first water pumping technique is considered to be the sha duf developed some 3 500 years ago and still used today Figure 1 2 illustrates that the shaduf is like a lever supported by a post in the middie On one end there is a recipient to hold wa ter and on the other a counterweight equal to half the weight of the water and the recipient This way the operator has to use the same force to raise the water as to lower the empty recipi ent By dividing the required pumping between a series of sha dufs each one raising the water one level higher water can be raised considerable heights with surprising efficiency The second basic step in this line of pumping technology is seen in the development of the norla translated from Arab
75. cial Models working on developing this model emphasizing greater depths In conclusion we feel it is appropriate to promote this model on a broader scale monitoring its use in deeper wells 11 1 Description The main difference between a rope pump for a hand dug well and a pump used in a drilled well is the small diameter of a dril ledwell 4 to 12 As the rope leaves the pulley wheel it is di rected by a guide towards the inside of the well this guide is the same as the guide underneath Depending on the form of the lining tube of the well and the pedestal if there is one the guide support can be welded to the well s metal cover or to the support structure The rope lowers into the well through the protector tube The function of this tube is greater than in a hand dug well as it pro tects the rope and the pistons from rubbing against the iron lin ing tube and the wall of the well If the well is completely lined with PVC tubing it is not necessary to use a protector tube In general the guide will not be placed at the bottom of a drilled well but rather 10 meters below the minimum static level de pending on the draw back of the well All of the tubing with the guide and the stabilizing rock are suspended from the metal cover with a clamp covered with inner tube to tighten the tubes the weight of the water column always weighs on the rope To prevent the raising main from getting deformed which will affect t
76. contact people have developed and researched a low depth rope pump for ir rigation use in Zimbabwe and Tanzania they have published various articles as well as a construction manual Robert Lambert and Richard Faulkner Leicestershire LE11 3TU England e peT oa dowe ETG e si ob O S 1 E T 1 HG 1 Iir 1 ia The success of the rope pump relies on the manner in which it is introduced into a marginalized community with the only resource being the community s desire to participate within a group project because the process must involve a program based on the community s social organization and self management The only methodology that results in the successful transfer of technology is that which takes into account the subjects of development providing for their collective participation and unlimited creativity Nemesio Porras Mendieta It is popular because in the first place it is made from our own materials It isn t necessary to bring in parts from somewhere else and its cost is within reach of people with few economic resources It is democratic because practically everyone has the right to participate in the installation and reparation including the women and children There is nothing difficult as see it Concepci n Mendoza Castro
77. ction 3 1 The raising main is made of common PVC Although the pro cedures for assembling are analyzed in detail in section 8 2 we give a general description of the tubing here The different tubes are glued to the flare to the bottom to minimize friction on the pistons The extreme interior has a flare to facilitate the en trance of the pistons and is fixed with an inner tube to the guide 0 3m below the well slab it is widened with a simple re ducer to the diameter of the discharge spout this tube croses the well slab by the anchor tube The widening of the diameter is in order to diminish the vertical speed of the water so that it will come out through the discharge spout and will not flow over All of the raising main with the guide and stablizing stone are hung from the anchor tube through a wedge made of a piece of tube with the same diameter as the discharge spout This is then connected without glue to facilitate its dismantling to the discharge spout through a J joint The pistons are attached to the rope by a piece of braided rope and burned at both ends see section 8 2 If the rope is not tightly twisted this method does not work so the pistons must be secured with two simple knots Particularly when using rub ber washers it is important that the opening through which the Chapter 6 Description of the pump 103 Piston Washer 7 Downward Upward friction forces driving force PES between tube and pistan washer f
78. d to its speed Experiences and development There are various models that have worked over the last 6 monihs without problems We don t see any particular problems of wearing out of parts We consider that this model pump can 172 Fourth part Special Models be promoted without any problem It would be worth monitoring models that have used long pipes more than 40 meters or that are very high above ground level more than 5 meters 12 1 Description By using a post to support the upper pulley wheel the raising main and the outlet spout water can be raised to a certain height above ground The motor force in this case is not ap plied at the highest point but rather at the height of the rim with a normal wheel The rope goes up through the raising main up to the post around the upper pulley wheel that spins freely back down loose and then around the working wheel about 270 before being guided by the upper guide into the protec tor tube to enter the well This guide is connected with rubber to the protector tube The design of this pump depends primarily on the kind of post being used Figure A 11 shows the case of a 6 meter high 1 GI tube while photo 29 shows a 9 meter high pump Another influencing factor is the type of outlet tubing and its path seefigure 12 1 If you need to pump water over a long dis tance the choice of diameter of the outlet tubing is somewhat more complicated than for normal pumps Table 12 1 gives
79. d at each level This is demonstrated in table 4 2 for two types of pumps technified and user built Table 4 2 Level of production of the pieces of a rope pump Se SS Sr lS The indicator T represents the tecnified pump and U the user built pump As can be observed in table 4 2 the user built pump could be built at home requiring that one buy only the rope and the PVC tubing which is the greatest obstacle The technified mod el can easily be built at the regional level while the wheel which represents 67 of the pump s value can be manufac tured at a local level In both cases there is no need to import parts although the raw materials tires steel PE are imported 74 First part The challenge of popular technology In Appendix B we have enumerated in detail all of the matenals tools and molds required for the production of the two types of pumps 4 2 Production Organization As we observed in the last paragraph the technical aspects of rope pump production are not at all complex The major difficul ty lies in the organization of production Six elements with very different characteristics need to be collected probably with six different suppliers For the technified pump these are materials for the concrete slab at the building materials shop the wheel in the metal workshop the guide in the ceramics workshop the PE or PP pistons in the extrusion workshop the rope i
80. d the coordination of this book s production comes from the team of the Rural Aqueduct Directive DAR in Region V in Nicaragua This team has been developing the rope pump for four years and has been implementing it in rural water supply and sanitation projects Many more people and institutions however collaborated and gave their opinions on the content and form of the book Although the information presented covers different areas of in terest and is directed towards different impact groups we decid ed for practical reasons to edit it in a single book It is likely 2 Introduction that you will only be interested in one or two of the four parts of the book In the first part we deal with the pump in general terms its history its fundamentals and its characteristics We also present the different implementation approaches and production aspects The section is directed towards those with general in terest project managers policy makers but also for interested users The second part is primarily directed towards technicians and engineers and deals with construction aspects The pump is described piece by piece with its construction alternatives Themechanical and hydraulic characteristics are discussed If at times we go into a lot of detail it is with the goal of being thor ough but for the great majority of the pump s applications the theory we present is not necessary The third part deals with practical and operating
81. d to a support structure through split bearings The support struc ture in this case made of welded iron can also be made of 88 Second part Construction wood Another visible part is the discharge spout of the PVC tubes However the heart of the pump is a rope that has pis tons every two meters These pistons can be cut from an old in ner tube turned from wood or extruded from PE or PP The rope passes over the pulley wheel and enters the protection tube which serves as a guide to pass through the well slab of concrete or wood Within the well the rope lowers freely At the bottom under the water level a guide of glazed ceramic or wood assures the fluid entry of the rope with the pistons in the raising main common PVC with diameter depending on depth commonly 1 2 3 4 or 1 When raised the rope with the pistons goes inside the raising main and returns by the pul ley wheel In order to leave the most important parts visible the figure does not show the pulley wheel protector When the pulley wheel handle is turned the pulley wheel is acti vated and friction makes the rope turn The pistons fit with mini mum play into the raising main and each one brings a certain quantity of water up Once the tube is filled with water the wa ter column moves uniformly up pulled by the pistons with a speed a little less than the rope this is due to the leakage be tween the pistons and the raising main It can be said that the e
82. de Part PP or PE pistons for rubber pistons Rope 10 6 Piston 20 18 Paint 24 24 Guide 36 6 Bearings 36 36 Outlet spout 48 48 Raising main Pulley wheel The useful life is given in months for the two cases technified and user built Conditions are relatively severe pumping 4 m3 per day with a pumping head of 24 m The numbers in highlights were deter mined in the field the rest are estimates Calculation Appendix A for parts distribution This creates dependence Until now our experience has been limited to structures directly linked to pro jects or small businesses that sell rope pumps In the majority of cases this is sufficient but in the case of institutional projects with determined ending dates continuityin the distribution of parts must be guaranteed through a network of private stores that guarantee parts at market prices Finally it is important to emphasize that it is preferable to imple ment a preventive maintenance system rather than a corrective system by strongly encouraging that the caretakers owners keep control over the pump parts that are subject to wear and that they change them before they break This subject will be elaborated upon in the third section In both cases hand built and technified we can conclude with certainty that the rope pump is a pump that completely fills the requisites of a VLOM 52 First part The challenge of popular technology H
83. die as a function of the pumping head for a range of volume per revolutions used by the Region V DAR as reflected in Table A 3 In this table we reflect some values for five com mon volumes per revolution F Calculating pulley wheel and raising main diameters 207 Table A 3 Recommended diameters of the pulley wheel and raising main depending on the pumping head The ranges highlighted are the most common 208 Appendix 10 15 20 ai Pumping head m Range of acceptabi forces __ Range of acceptable mput powers __ __ Figure A 8 Force on handie and input power The figure demonstrates the force on the pulley wheel handle and the power required as a function of depth it takes into consideration the four volumes per revolution presented in table A 3 1 2 0 7 0 4 and 0 25 liters The calculation of inputpower was made assuming a speed of f 0 8 revolutions per second The two bands give the acceptable ranges from the ergonomic point of view As may be noted the limiting factor is the input power and not the acceptable forces In the case that the pump requires greater forces the user will turn it more slowly to maintain sustainable power That will lower the piston speed and thus the yield As we have defined VOLrev we can take advantage of this enti ty to easily calculate the flow Qreal Qreal hyd VOLrev f L s 6 With the calculation method presented in this appendix the force on the pulley wheel
84. dvantage of this approach is that the user understands the technology and at any time can repair adapt or change the pump Therefore we can really talk about Chapter 1 A developing technology 29 a popular technology and guarantee that there is real interest and confidence in the new technology The technology is not limited to the apparatus but rather forms part of a broader train ing and development process reinforcing confidence in one s own Creative efforts A disadvantage is the limited impact not everyone has the skill to build their own pump and the technical limitations which pre vent building pumps for deeper wells Another problem for large scale growth is the lack of a materials distribution network outside of the regional capitals especially in terms of small quantities of tubing and accessories Institutional projects could help in this aspect Sales The sale of pumps emerged closely related to the previous ap proachy A peasant after having participated in a pump con struction workshop begins to build and install pumps for other residents He develops skills and special tools without giving up his previous job This phenomenon is found frequently There are also broader initiatives where various people work fulltime and have made significant investments to accumulate pumps secure transportation put out publicity etc Both cases demonstrate that the pump is viable free market mechanisms show that both bu
85. e 2 m s speed that it considered optimal The third factor is the distance between the pistons Hpis Fig ure 7 3 shows that efficiency drops steadily but not very sharply It is logical that minimizing this distance improves hydraulic effi ciency but at the same time it causes a serous decline in hy draulic efficiency due to the friction between the pistons water and raising main We don t know the exact magnitude of this fric tion but we suspect based on experience that the optimal dis tance is around 2 meters s 2 Q D O a T gt T 2 29 j 4 Distance between ee His mM Figure 7 3 Hydraulic performance as a function of the distance between pistons Hpis Values are valid for 0 4 mm and Vpis 1 4 m s As can be seen in the three graphics a fourth influencing factor is the diameter of the ralsing main tube Otub We have al ready explained how this affects efficiency However its impact is not sufficient to be able to optimize the pump s efficiency For example a 1 tube at a speed of 0 5 m s results in poorer effi ciency than a 1 2 tube at a speed of 1 5 m s although both combinations result in the same force exerted on the crank Chapter 7 Mechanical and Hydraulic Characteristics 129 The main point of the graphics is to illustrate the effects of vary ing the different factors If the dimensions of a pump approxi mate the values mentioned in the graphics one can see the pu
86. e a manual pump that re ceives intense use requires certain strength There will always be inadequate use careless users unruly children etc and any pump should be designed to resist such situations Many producers have tried to make pumps which resist any kind of abuse or vandalism We think the importance of this should be put in perspective because if the users don t care about the pump if they don t take care of it clean it maintain it or use it propery for drinking water it will have no impact on health And why install pumps under these conditions Only to achieve higher coverage rates If a user values the pump she will automatically care for it repair it etc The rope pump is based on the principle that the owners users should take care of it If there is no social control the rope pump will not work as it is Currently designed since it is Susceptible to any robbery of parts or injury In the case of community wells a Drinking Water and Sanitation Committee of three to four members is usually formed prefera bly women to take charge of organizing care cleaning adminis tration and maintenance of the well and the pump Another suc cessful alternative is the private public well one family makes its well available to a defined list of other families and the pump is installed This way the well is for public use but receives pri vate care 42 First part The challenge of popular technology 2 5 Village Le
87. e balls de scend from the depository through a funnel and pass through the elec tric heater the voltage regulator is seen above towards the mold not installed To the right the lever which presses the mold On the chart In front a sample of three molds with their 1 2 1 and 1 4 pistons Emphasize strict delivery dates including fines within the con tract for days or weeks behind schedule From the very beginning demand sufficient quality of the sub products In industry it is common to use a large contract to invest in the improvement of production methods In the case of micro enterprises we think it is important to explicitly separate the de velopment of a sub product or new method of production with production on a larger scale making different clauses within the contract Chapter 4 Production 79 Photo 13 and after The mechanism for introducing the raw material has been im proved through the use of an electric motor with a transmission This photo shows the opening through which the liquid polyethy lene comes out Jose Evaristo Workshop Managua 1 Develop a production system with X and Y molds for a value of xx C 2 Produce a quantity of parts at a unitary value of yy C The workshop will not lose much if the effort fails and will not be obli gated to deliver products of insufficient quality With these observations we conclude the subject of production and pass on to the perspecti
88. e how to calculate certain key measures of the pump 114 Second part Construction Dorie Bargman and Willian Israel Torrez Munguia Puente de Paz What is the purpose of promoting the use of the rope pump We as Puente de Paz have been working here in potable water pro jects in the countryside The purpose and objective of installing rope pumps is to provide a safer method for drawing water It is also to have an impact on heaith because the well is more or less covered When the wells are communal we install the pumps and request that they use concrete And when the wells are private what we do de pends on the resources of the individual But the wells must always be covered and given a chlorine treatment in order to have a positive effect on health and make things easier What are the characteristics of your rope pump In the communities with the owners we all construct the pumps out of wood because the low cost makes it more accesible to the popula tion The wood can be found in the countryside We supply the tubes or we buy imported tubes and there are homemade ways to con struct them The type of piston we make is totally homemade we use an old tire and the wheel around the handle is also of rubber Every thing is simple The type of handle that we use is easy to take apart There are only three pieces so it is easier to take apart and put back together Any damage to the pump during use can be easily repa
89. e right to participate in the installation and reparation including the women and children There Is nothing difficult as see it Humberto In regard to the other pump there is no democracy We need a technical team and only this team can do the work so no one else can participate because they don t know the system they can t do it It has to be done by the technical team from INAA What Interests are Involved In the marketing of the pump Concepci n For a promoter his or her particular interest is social to create conditions which are going to improve the living conditions of the people of the community to orient them in how to better their Chapter 3 Rope pump characteristics 55 situation Whereas an individual or someone who sells pumps has an economic interest in bettering his or her own situation In fact what interests thems filling their own pockets and they don t give all the recommendations necessary in order to assure that the pump purchased by someone doesn t fall apart all the time So theirs is an economic interest and ours is social Humberto I have even felt more at ease in my work when arrive in a community and they say You know this pump here broke the rope because it got stuck but we already bought a new one and it s functioning feel as though our work has been a success feel that am developing my work What do you think about the Issues of water quality contro and publi
90. easurements they should be chosen based on the following criteria range of interior diameters of the tubing and its uniformity the play that is to be maintained the choice of materials which depends on their composition which defines both physical and mechanical charactsristics With respect to the mold depicted in the figure it is possible to omit the insert making it one piece with the male part None theless this requires more precision while turning the lathe The mold is designed in such a way that neither the injection ori fice or the union of the female and male parts affects the smooth surface of the piston s outer border If a milling machine is available multiple molds may be made which would signficantly step up the pace of production Injector machine The injecting machine can be either manual or electric the pres sure in the mold should reach 100 N mm2 Heating is electric and the temperature should reach 200 degrees C Photo 34 Piston molds Three molds for cast pistons in their simplest form in the first row the female parts in the second row the male parts with in serts and in the last row the pistons From left to right 1 2 1 y 1 4 Jose Evaristo Workshop Managua E Specifications of the glazed ceramic guides 197 Appendix E Specifications of the glazed ceramic guides In this appendix we describe step by step the production pro cess of the glazed ceramic guides
91. echnology Ecumenical development organization works in latrine traditional and compost water tank and rope pump construction Cristy Stickney adviser Del cementerio occidental 2 c al norte Apartado Postal 3091 Managua Offices 505 2 664507 666102 664212 Workshop 5052 50389 505 2 664326 CICUTEC Non profit popular communications as sociation Edits among other things the ENLACE magazine i Counts among its collaborators several worked with rope pumps for many years Edited and distributed this book Antonio Belli coordinator Eduardo Oroz co and Boris Engelhart collaborators De la CST 1 c abajo 1 2 c al sur Apartado Postal A 136 Managua 505 2 662643 ches 75 Appendix Name Description Contact Address Tol Fax Name Description Contact Address Tel Fax 221 COOPINIC Nicaraguan Innovators Cooperative Cooperative that produces various prod ucts based on appropriate technology in cluding hydraulic ram pumps and rope pumps The adviser Jan Haemhouts Is co author of this book and has been in volved in the development of rope pumps in Nicaragua since 1983 serving prior to that as an adviser in Haiti Jan Haemhouts adviser Del cine Salinas 1 c al sur 1 2 c abajo a 505 2 23947 CEDIN 505 2 66 1366 Jan Hamehouts 505 2 23947 DAR Region V The regional representation of the Nicar aguanRural Aqueduct Directive of the n
92. ective diameter of the pulley mm and w Real interior diameter of the raising main mm In working with these formulas we must respect the units used in this list The formula that defines the torque on the pump handle is Dput Fhandie 1 Mmec X X 1 4 X Qu Oiope X o X g X Hhe sd Dnandie 1 This formula can be simplified by introducing two combined variables C a constant N m Ltr and VOL Volume per revolution Ltr 6 ERRATA oXgX10 C _______ 78 N mxLtr 2 Nrope X I X Qhandie VOLiw Bou X TI 4 X re B rope X 10 Ltr 3 We note the the volume per revolution VOLe combines the only two variable parameters that define the force over the lever O w and O pu In other words the volume per revolution is a measure of the forces acting on the lever Now we must take into consideration that the speed of the piston influences the hydraulic efficiency see appendix G The rotating frequency of the pump handle f assumed as optimum for the user in the range of 0 7 1 s 1 defines Vps speed of the piston varying between 1 and 1 5 m s while the optimum speed estimated at 1 5 to 2 m s It thus implies attempting to maintain O pa maximum 540 mm which corresponds to a rim of 20 and varying the diameter of the raising main O w Let s return to the calculations Introducing C and VOL equations 2 ar 3 in equation 1 gives us Fhandie VOLrew X C x Hheas N 4 and also Pin
93. eeded to maintain tension around each spike two people to lift the post and a coordinator to watch and direct Once the post is upright and the tensors are tight and secure the installation of the pump can begin cut and connect the two parts of the raising main guide the rope through the upper guide and tie it Finally install the outlettub ing according to the specifications required by the situation 176 Fourth part Special Models aP A ai 2 e m Photo 30 A high diecherge pump The photo shows a pump used by the DAR Region V for emptying the wells One can see the two cranks the absence of a block ing system and alongside the pulley a 1 1 2 piston Santo Tomas 40 meters of 12 wire 3 0 8 meter iron or wooden spikes an upper guide more rope and pistons outlet tubing ac cording to the specifications re quired by the situ ation Chapter 13 High discharge rope pumps Issues Involved In many areas the need exists for the ability to pump using hu man energy greater quantities than can be pumped with a nor mal rope pump For example to pump welis dry irrigate small areas water cattle etc Many times no energy source other than human labor is available Description of model 13 The high discharge rope pump is nothing more than a strong pump with a larger diameter raising main and two pulley wheel handles The raising main can be 1 1 2 or 2 inches according to
94. eg a wood en pulley Santa Cruz aspect Production took place in the San Jos Industrial Cooperative with the support of a former CITA advisor 20 First part The challenge of popular technology Don Pompilio How did you become familiar with the rope pump When the rope pump first came to the CITA INRA Center many people were invited to come and learn about the project There were many projects with animals with windmilis But what most attracted my attention was the little pump it was the easiest to learn What conditions are necessary for the construction of this type of pump There is the tube the rope the pistons which we might make one by one but now that they are made in the factories in Managua we use those instead if the chent wants them made of old tires then they are made of old tires but if not then we use the pistons made in Managua This is what say to the owner You are gomg to supply me with the wood nails and rope make nothing except the pulley wheel and the guide tell him to get me a Ceramic isolator in order to form the guide so that the pistons work correctly and won t wear out To date have constructed 290 pumps that s all What procedures do you follow when they experlence problems i explain how to change the pistons and how they have to have the ropes and the pistons reddy how to make the transfer without taking out the tube You just let t go loose pull t in rev rse
95. eight of the post The outlet tubing can begin at the level of the rim without much loss This Is the most desireable situation Figure 12 2 Outlet tubing for a post mounted pump Chapter 12 Post mounted rope pump 175 Embedding the pump The anchor for the post the delivery tube and the pump wheel are in a line where it is important that the anchor is positioned on top of the rim so that it is well supported The protector tube is located off this line to prevent the rope from rubbing against itself The anchor is a piece of 1 Gi tube embedded in the concrete slab sticking out some 50 mm above the slab To assureaa strong embedding in the concrete pieces of iron are welded onto it Installing the pump Having placed the slab over the rim the pump is installed in the normal way leaving about 200 mm of the raising main sticking out of the delivery tube The rope immediately passes through the raising main secured to the lying down post It is easiest to fasten all of the tubing and the rope to the post even though it is only provisional before raising the post This is to minimize the work that would have to be done above once the post has been raised After securing the tubing to the post connect the three tensors and bury the corresponding spikes Lifting a 6 meter high post is a job that requires good planning and above all good coordination so that no one is put in danger At least one person per tensor is n
96. ell and in no time we are back where we started from except worse off because now they have water with a higher concentration of microbes there is no circulation and we are generating more illnesses in the community with this huge pile of broken pumps accumulated in x number of months Concepcion In reality that is going to depend on the knowledge that has been acquired regarding improvements to the pump and the problems that it has resolved in the rural sector It is going to depend on the degree of knowledge on the part of both the financing organi zations and the government institutions in order to fully understand that here in this country what is needed is a solution brought about by ourselves with our own resources The rope pump has a better future because it is more widely accepted due to its low cost and high output which is something that is of special interest to the pri vate producer Humberto I think that it is better to make use of this type of pump here because it results better for the communities also think that throughout the time that we have been working the rope pump has been in first place here How would you describe your direct participation In this technology Concepci n in fact we as promoters have immersed ourselves in the development in practical terms What happens The engineer can design the pump or the man who can build it builds it But those who have experience in using it and
97. eriod as shown in Ap pendix A We include these expenditures within the mainte nance and operation costs 70 First part The challenge of popular technology To compare the cost of the rope pump with other well known pumps see figure 3 6 Pumps for 12 m head __ a q 2 5 3 o ai m Q n o _ Tara Unimade_ _ Rope Afridev Indan Maya Mk fl pump Mk III Figure 3 6 Prices of different pumps The prices of a rope pump compared with other known pumps which are competitive in the range of depths of 0 10 meters and 10 30 meters In this chapter we analyzed the different characteristics of the rope pump operation and maintenance reliability discharge rate pumping head efficiency rates water quality protection and finally costs We now look at production issues Chapter 4 Production 71 Chapter 4 Production One of the strong points of the rope pump is that it does not re quire a high level of technology for production and can be pro duced in any country with a low industrial development level Since many designs of the pump exist it is not possible to gener alize and we must differentiate by model and by piece to ana lyze the aspects of production We will do this in the second part Here we limit the analysis to the production levels required for typical pump models section 4 1 and explain how produc tion is organized and how to involve small and micro industry in this process
98. ers for its continued development and for its adaptation to particular cases The transparency of its workings and structure invites owners and users to experiment with the pump exploring all of its parts One can see many pumps with innovated im provements made by the users themselves rubber here anex tra lever there more pistons homemade wooden guides They don t always mean substantial improvements and are often based on an incorrect analysis of the problem At any rate it in dicates that the users have incorporated the technology and are not afraid of exploring and examining their pump The true understanding of a technology therefore implies more than the handing over of the pump with a supply of spare parts and a user s manual It implies the need for users together with makers to explore the pump with the goal of experimenting analyzing and testing new ideas We think that this has been the basis of much of the rope pump s success in Nicaragua We can affirm that artisans and users have supported much of the rope pump s development They have actually played a much larger role than the techni cians and engineers As we saw in chapter 1 in Nicaragua we have many ways to promote the technology ranging from open sales with no train ing to construction by the users themselves The latter concept obviously fits in much better with the philosophy of the rope pump as described here but it has its limitations it dema
99. ers that fall on the slab impossible and the possibilities of contamination by the rope also seem minimal particularly when a protection for the pulley wheel has been n Stalled Figure 3 4 demonstrates a comparative study of water quality in sealed wells with a rope pump and with Dempster pumps It can be observed that there are not great differences between the two categories of wells and although the sample is small it can be concluded that other intangible factors are more Impor tant to water quality control than these different types of pumps Chapter 3 Rope pump characteristics IZ Dempster sample 35 Rope pump sample 31 Ur pf f Yj f J r YY MM WH ZZ We Percent of wells WL We MMM WY WY NY Wi YIN _ YUN N 0 10 10 gt Number af E colis 100 ml Figure 3 4 Well contamination 65 The quantity of E coli per 100 ml in water samples taken from sealed wells with rope pumps and with Dempster pumps The data comes from 66 samples taken by the UNOM team in Nueva Guinea and in Boaco Wells were chosen which eliminated possible nega tive influences like poor locationof wells because of streams or la trines poor lining quality of siab or rim poor sanitary conditions and maintenance of well and apron if chlorination took place after the last opening The greater number of samples from Dempster pumps is due to the fact that there are more wells with this ty
100. esent the detailed plans in this book we limit ourselves to showing the photo 11 2 Installation The design of the pump and therefore the installation de pends mainly on how the the drilled well is built the material used the diameter and height of the well s lining tube the di mensions of the base if it has one etc As with pumps for hand dug wells this installation also requires two half days one to embed the support structure and the other for the actual installation Embedding the pump In general the pump s support structure is embedded in the apron The positioning should be such that the raising main is exactly plumb underneath the pulley wheel The base for the outlet spout should be placed at a height so that it is easy to put on and take off the bucket Its section is 150 x 150 mm mini mum with a reinforcement of four rods Embed the outlet spout If the height of the spout allows it s wise to make a plat form for the users to put their buckets on leaving some 500 mm between the spout and the platform When you coat the apron with cement take into account the space needed by the two users At the same time pour the triangular stabilizing rock see figure 11 1 Chapter 11 Rope pumps in drilled wells 169 Installing the pump Once the total depth of the pump has been determined place the pistons on the rope pass it through the guide and the rais ing main Since drilled wells are generally deeper
101. essary to make pistons but working carefully they can be made perfectly well with a sharp Knife That is to say it isn t totally necessary but we use it to do the work faster You don t need lots of things if you want to do it simply The pumps built in this way are usually rustic and simple but represent the effort of the users themselves The felt need of the beneficiaries self sufficiency and the transfer of technology are important advantages of this approach One discrepancy between those who have worked with this ap proachy is related to the manner of communication and promo tion if thisis done through construction training workshops or 26 First part The challenge of popular technology Ramon Jimenez Mendoza self builder How did you first hear about rope pumps Well quite simply we participated in the Farmer to Farmer Project and through it we were able to obtain a copy of the magazine En lace In which there was an article that explained about rope pumps We needed the pump because with this rope pump my problems could be solved and it could be constructed very economi cally No have never seen a pump other than the one that have made No haven t seen one What does one need to construct a pump In terms of both knowledge and finances in terms of money didn t spend much because already had the tube did have to buy the t joint and two lengths of rope that bought for diez cordobas per ro
102. established for groups without resources In addition to these project activities it was decided to promote the pump through a publication a de cision which was made a reality through this document As a product of the Bluefields and Region V expenence INAA decided to incorporate the rope pump in a broad study of low cost rural sanitation technologies carried out by the Engineering University UNI in 1989 Although the study had interesting re sults it did not go beyond the laboratory phase and had practi cally no relation with the countryside See Ballesteros M 1991 Given the great demand generated by the rope pump in 1990 the Rope Pump Society was formed This private initiative took on its business with great energy traveling from fair to fair using radio announcements and covering the country in trucks full of pumps looking for clients They achieved a monthly sale rate of 50 to 60 pumps The society is not only dedicated to 24 First part The challenge of popular technology sales but also invests in pump improvements and in the devel opment of special models trying to monopolize on innovations There are also other projects promoting the rope pump initiated by organizations like CEPAD Bridges of Peace and COOPINIC Although they do not currently produce great quantities they ac cumulate experience and develop different implementation ap proaches For an idea of the number of pumps installed over the last
103. ey are lubricated When the bearings have to be changed the lower bearing can be removed with a hammer e Oil is better than grease because it cleans the bearings e Lubrificate the bearings with regular oil every 4 weeks e Use axles and bearings of galvanizad pipe if possible The galvanizing works as a lubrication Construction when Fixed bearings An other possibility you want the Installed in some is to use bearings possibility to 1500 pumps no of wood pulley remove the pulley big problems and bearings pulley not removable removable 4 Annex 7 3 SPOKES AND DIAGONALS In the several pump designs sometimes there are problems with broken diagonals or spokes Reasons e Welding is of bad quality and or material is burned there is corosion especially on the welds e The diameter of the spokes is to small 5 mm Diagonals are not welded triangular if pump structure can move parts and especially welds can break Suggestions e Use spokes of minimal 1 4 6 mm but even better a larger diameter for example 3 8 8 mm 4 THE BLOCKING SYSTEM fig A3 page 193 Of several pumps the mounting welding as on photo 15 is broken Almost all alternative systems see photo 16 are broken Reasons e The welding in this way don t resist the big forces Rope Pum 5 on the blocking systems e If the blocking system is close r to the axle the forces become big ger S Suggestions
104. for intensive use it can pump up to 32 bar rels daily 8 mS But even more important than this data is the fact that the pump is easy to construct operate and maintain One central characteristic of the rope pump is that it can be easily adapted to different types of construction in Nicaragua we know of pumps made only of wood and rubber materials cost US 13 and of models using iron injected polyethylene pieces andglazed ceramic total cost US 45 In terms of water quality protection there is a theoretical possibility of contamina tion but practical data thus far have demonstrated that contami nation is no greater than in wells equipped with other pumps The pump can be adapted to different conditions there are spe cial models for drilled wells to pump water above ground level pump on a post for large volumes irrigation cattle watering and with movements for a motor or a simple windmill The last two models are in the development phase while the others can be used without any risk New research and development of the pump are not being car ried out in a structured manner for lack of resources directed specifically to research but it does take place in an ad hoc manner Research is currently concentrated on drilled pumps and on the special models already mentioned In addition to covering what has been mentioned above the book details the design construction installation and mainte nance of the pump taking in
105. fracture See problem 4 Pochote 158 Problem 1 Third part Installation operation and management Symptoms the rope moves but gets stuck at regular intervals By pulling it harder it loosens and moves a few meters The ob struction may vary from being almost complete to being barely noticeable Possible causes The raising main has some defect or obstruction that is causing the pistons to rub or get stuck when they pass This could be 1 The widened flare at the opening is constricted 2 The inner tube that tes the tube to the guide Is too tight deforming the tube 3 One of the flares is constricted a common manufacturing defect 4 Some kind of damage in the raising main for ex ample someone stepped on it or it got bent 5 The inside diameter of the tube is not uniform bad quality Solutions Find the defect or obstruction by observing the position of the pistons when the rope gets stuck Watch to see if the rope stretches a lot this problem is described below if it doesn t stretch much the prob lem is close to the top 1 Cut the fiare and make a new one 2 Loosen the innter tube some using no more than 3 layers Did you use the rein forcing nipple If the defect doesn t disap pear they only solution is to use higher schedule tube This means you also have to change the pistons 3 Cut the constricted flares and make new ones by heating the tube or
106. gh health education cam paign which should especially emphasize the adequate transport storage and use of drinking water If this does not take place the impact on health which is the final objective of any drinking water project will never be achieved 40 First part The challenge of popular technology 2 3 Self sufficiency Another taking off point in any development activity should be that outside support not be perpetual but only serve as the im petus to developing viable alternatives Many times projects come to an end do nors leave and only leave behind a limited number of wells with pumps Rather than multiply sooner or lat er they break down for lack of maintenance This is not develop ment The projects should develop an al ternative which s a re alistic option for the benefitting population even without the inter vention of a donor an option that can be pro duced bought in Stalled and repaired A pump for rural areas should be inexpensive and easy to produce nationally preferably at the local level The rope pump Is one of Photo 8 Our commission Is the few technologies EOmpo sec SEY St women Women from a potable water committee to known today which ful gether at their pump which ts well protected fills these prerequi by a box and a fence urban area Nueva sites Guinea Chapter 2 Basic rope pump concepts 41 2 4 Social control Logically a piece of equipment lik
107. gies logically in function of crite ria which favored industry growth The following are character istics which promote large scale industrial growth minimum weight and volume in relation to potential which is achieved using minimum force at high speeds standardization in production and universal use which permits centralized massive and therefore inexpensive produc tion a certain complexity and limited durability which limits mas sive plagiarism and maintains demand by avoiding market satu ration Fhe concept which most closely matches these criteria among the broad array of existing pumps is the centrifugal pump based on the creation of centrifugal force using blades on ro tors turned by high velocity motors Despite relatively low effi ciency this allows high power transmission at very low volumes The concept of pumping with a chain actually contradicts the above mentioned characteristics it is relatively large and heavy and uses great force at limited speed t can be easily adapted to local craftsperson production it is not as universal as the centrifugal pump which automati cally adapts volume to pumping height it only raises water to the pulley level Chapter 1 A developing technology 13 Clearly the chain pump cannot compete with industrial pumping equipment and since it does not coincide with interests that di rected development of industrialized countries its application re ma
108. h ease and make possible the quick dismantling of the axle Figure 6 4 demonstratee how the pulley wheel is made of two pieces of inner tube united under pressure by the portable pul lays The form obtained is a V and guarantees high friction between the rope and the pulley wheel The eight pulley sup ports are connected to the axle through spokes crossed as on a bicycle The diameter of the pulley wheel depends of course on the availability of old tires but in section 7 2 we give criteria regarding the selection of the optimum diameter of the pulley wheel in relation to the other factors that influence it We princi pally use old tires of 20 with an efective diameter of 540 mm It is important that the tires be from heavy vehicles so that they are rigid and do not open with the pressure from therope Chapter 6 Description of the pump 93 The support structure is immoving since it is embedded within the well slab it is important to protect it well against corrosion We use an extra thick iron 5 8 for the feet The piece can also be galvanized 4 The structure should resist force from all directions particularly from children who use all of their body to move the pulley wheel handle The blockage system see photos 15 and 16 keeps the pulley wheel and handle from turning in the opposite direction of the pumping It is subject to shocks Its functioning is simple the lever should allow the pins welded into the pulley wheel t
109. h the knot This provokes instability which should be corrected continuously by more friction To the E g D c U L Minimum Figure 6 6 Variation of tube diame The figure illustrates the variation of the internal diameter of PVC tubes of 3 4 SDR 17 from three different factories Note that the variation between the diameters of the pistons is much less than that of the tubes Source Heuthorst 1991 Chapter 6 Description of the pump 105 contrary in the new model the point of application as well as the forces of friction as the result of the hydraulic Water pressure are located below the upward force of the rope creating a stable equilibrium In this manner the friction Vacuum between the pistons and the raising main has been signifi cantly reduced as well as the hydraulic losses due to the pistons leaning The conic form also facilitates the passage through the guide and the entrance into the Loose raising main pistons Tight piston Apart from the form there is another crucial factor the play between the piston and the raising main should be minimal It is not possible to diminish the difference be tween the real diameters be low 0 2 mm because the variation in diameter of the tubing will not permit it In fact the pistons are made with greater precision than the tubing See figure 6 6 Minimal play results in very high hydraulic efficiency Figure 6 7 rates
110. handle Fhandle and the input power Pin can be easily calculated and thus the optimum values for the raising main tub and the pulley wheel diameter po1 may also be determined We can also see how to calculate the pump flow Qreal F Calculating hydraulic efficiency 209 Appendix G Calculating hydraulic efficiency In section 7 3 we discussed the mechanical and hydraulic effi ciency of the rope pump and we referred to this appendix for the calculations Thus we now present a theoretical model for the calculation of hydraulic efficiency developed by Heuthorst 1991 We first present the model and then discuss its validity defining its premises and limitations and comparing it with data found in the literature Presentation of the model Above all it is important to emphasize that for convenience in this appendix all the values Introduced in the formulas are in units of the International unit system The difference with the preceding is that all the measures of tube and piston diame ters etc are in meters and not in milimeters and the flows are reflected in m3 s instead of Ltrs s To calculate the hydraulic effienciency hyd we need to calculate the loss flow Qloss that drips out in the ndragow ring between the piston and the wall of the raising main ias A a i ee Qiheor Qtheor We define the direction of Qloss downwards as positive Qteor is easy to calculate Qtheor V pis Diu Dregs m3 s _ o a 2
111. hart the following conditions must be taken into account i The same wholesale prices were used for the user built pump as the technified pump In practice if the user built pump is not supported by a project its real cost could double or even triple given the great difference existing between whole sale prices and prices in the departamenta tool shops Nicaragua today is an expensive country to produce in pro duction efficiency is very low and salares are relatively high Costs may be lower in other countries The values shown are the sale prices of the suppliers of each piece The installation and assembling costs are small in the case of a wooden cover 1 2 working hours in the case of a con crete slab 8 working hours But the collection of the parts from the different smali businesses that produce them requires a sig nificant investment i e the metalworking shop for the wheel the rope weaving shop for the rope the injection workshop for the pistons the ceramic workshop for the guide and finally the factory for the PVC pipes The cost of running around to find all these pieces although it could be significant cannot be quantified and cannot be taken into account p The cost of a machine does not mean much if its useful life is not known We estimate the useful life of the wheel which rep resents the greatest cost at about 10 years The other parts will be changed within a certain time p
112. he passing of the pistons the tube reducer between the rais ing main and the outlet spout should be placed underneath the cover Chapter 11 Rope pumps in drilled wells 167 Another difference with respect to a normal pump is that drilled wells don t have a rim the support struc ture embedded in the apron is taller the ideal height for the axle should be 800 to 900 mm Since it is taller it needs to be stronger the iron legs should be of 3 4 instead of 5 8 with support braces on all four sides In addition a sec Sate ond crank can be KE added increasing a any the load on the a Photo mea inion ac he drilled well bearings the axle S was aesignea based on experiences with the pump In El Pochote The axle is a 1 4 Gl Bo Mie etre pipe and the pulley is placed between the bear p ings but not directly over the center in order to al tation for various low for the blocking system The well is hermeti users including cally sealed by the slab Nueva Guinea children the sec ond crank can be of a different diameter and at a different height with a platform or stool 168 Fourth part Special Models Although the current design was developed in the DAR Region V it is a second generation design and has supposedly over come some of the deficiencies of the earlier models like the Po chote model we still don t have enough long term experience and therefore prefer not to pr
113. he pump are considered more important than the pur 68 First part The challenge of popular technology chase price For the self sufficiency of a rural population with little resources however the pump s cost is very important The low cost of the rope pump makes it possible for wide distri bution given that many people family nucleus or several fami lies are willing and able of paying this sum for a pump keeping in mind the low installation and maintenance costs Table 3 4 Costs per piece of rope pump in US dollars Pumping Head 24m Value Value Piece Wheel materials Wheel production Guide Discharge tubes Raising Main Rope and pistons TOTALS 44 73 100 13 13 100 Graph 3 5 and table 3 4 demonstrate the costs of the pumps by piece and depth The following observations can be made The costs increases are relatively small given the depth of the well much less than with other pumps This is due primarily to the use of PVC pipes with a small diameter a relatively inex pensive product The following phenomenon can also be ob served greater well depth smaller pipe diameter and therefore lower costs of pipes per meter Chapter 3 Rope pump characteristics 69 The cost of the rope and the pistons increases almost lineally with depth although this cost is relatively low it does significant ly influence the recurring maintenance costs See section 3 1 When analyzing the data in the graph and c
114. ide Technical guide hollow guide Pump handle torque Parameters for the model to calculate hydraulic eficiency Figure A 10 Profile of flow in gap between piston and tube Figure A 11 Technical drawing wheel on a post 86 89 94 96 103 104 105 109 126 127 128 136 137 138 142 143 145 146 147 169 174 191 192 193 194 201 202 203 208 211 210 216 List of Tables Table 3 1 Maintenance costs 50 Table 3 2 Useful life of the pump parts 51 Table 3 3 Daily pumping hours 61 Table 3 4 Costs per piece 68 Table 4 1 Definition of technological production levels 72 Table 4 2 Production level of the parts 73 Table 6 1 Advantages amp disadvantages of slabs 91 Table 6 2 Advantages amp disadvantages of bearings 98 Table 6 3 Advantages amp disadvantages of systems 99 Table 6 4 Advantages amp disadvantages of 2 pulley wheel locations 100 Table 6 5 Advantages and disadvantages of four types of protection 101 Table 6 6 Basic data about the raising main and the pistons 106 Table 6 7 Advantages and disadvantages of four types of pistons 107 Table 6 8 Advantages and disadvantages of five types of guides 111 Table 6 9 Advantages and disadvantages of PVC or GI outlet spouts 113 Table 7 1 Recommended tubing and pulley wheel diameters 121 Table 7 2 Advantages and disadvantages of varying the tubing diameter 122 Table 12 1 Selection of outlet spouts for post m
115. if necessary steel cover for the lining tube with its clamp wood to frame the Fourth part Special Models Photo 29 Post mounted pump One possible arrangement of the pump on a post filling elevated tanks to create closed gravity systems This model is from the Rope Pumps Society Los Cedros apron the base for the outlet spout and the platform Chapter 12 Post mounted rope pump 171 Chapter 12 Post mounted rope pump Issues involved There are many cases in which it is necessary to pump water to some height above the ground in order to achieve certain pres sure This could be to transport the water through pipes over long distances or to fill tanks on a tower structure for example to have a closed water system scope of Model The main limitation of this model is the limited amount of availa ble human energy filling a 500 liter tank from a 20 meter drop for example fom a 15 meter deep well to a tank 5 meters above ground takes about an hour an amount of time we con sider to be the daily maximum For reasons of stability and for the mentioned energy limita tions the maximum above ground height we recommend is about 8 meters The maximum distance water can be transported by pipe is 70 to 100 meters assuming flat terrain One problem is the start up there will inevitably be water wastage at the beginning over flow ar the outlet until all the water in the pipe has accelerate
116. ilders installers and clients are interested in the pump This is the best guarantee that the tech nology will survive without outside interference The greatest emphasis of this approachy is in the felt need of the beneficiaries of course and in local production The advantage of this approach is that it is both agile and flexi ble and offers accumulated experience many installed pumps which permits innovations not only in the pump itself but also in its production and installation If there is not a closerelationship with the user there is a danger that the seller forgets the First part The challenge of popular technology Alfonso Arag n Amador Palo de Hule Promoter What exactly is the Palo de Hule and how does it function Well the Palo de Hule is a foundation just beginning to function We ve been operating for a year and in addition to the assistance we receive from the Dutch we receive support from the Juan XXIII Institute with our work here in the store People with extremely is a short form that they must fill out with their full name address the type of material they are buying and their signature There is aliso a section in which they state whether they have the ability to pay the full price or whether they need credit or a discount In the store we have everything at least in terms of tubes of al diameters wrenchs everything related to potable water We also have chlorine sand cement cement
117. in their own way and anonymously to the children who treat the pump like a toy and thereby submit it to excellent tests of force to the mothers who as the primary users make comments criti cisms and suggestions coming out of daily use to the innovators who continually change components and add accessories to their own pump to the promoters and installers who share all of the quirks of installation in any kind of well and finally to the technicians students and engineers who with their calculations models and designs contnbute towards a bet ter understanding of this technology hope that this book will be one more step in the development and distribution process of this fabulous popular technology that is the rope pump Juigalpa November 25 1991 Bernard van Hemert at Summary The initiatives of many people and institutions have developed and promoted the rope pump in Nicaragua over the last eight years The initiatives include different concepts designs and approaches Development has been primarily directed towards the drinking water supply from hand dug wells with depths from 5 to 30 meters The development and implementation of the pumps has been within the concepts of appropriate technology all implementation activity begins with a felt need by the beneficiaries this also influenced the pump s design o impact health it is considered more important to guarantee large quantities of wa
118. indicate that the quantity of water used increases significantly when the source is closer An area with many dug wells should be taken advantage of even when their hygienic conditions or physical characteristics are not optimal it costs the same to install a robust and her metical pump in a new central well as it does to install 15 or 20 rope pumps in various private or communal wells improving the wells with slabs rims linings drainage troughs It must be de cided which will be preferred by the community In terms of water quality there is no confusion When we talk about limitations in protecting the source we refer primarily tothe wells bad location proximity of latrines with no sanitary seal and not to the rope pump As we will see in section 3 4 Chapter 2 Basic rope pump concepts 39 Photo 7 The pump in the partor Studies have shown that decreasing the distance to the water source increases water consumption This has a positive effect on health Nueva Guinea the rope pump appears to give the same water protection as traditional pumps It is interesting to mention here a related aspect that high water consumption has an unexpected positive effect water spends less time sitting in the well which prevents excessive bacteria growth in the water To conclude this section on health impact it is important to em phasize the need to accompany the introduction of improved wells and rope pumps with a thorou
119. ined limited to those countries where it formed part of the cul tural heritage and where craftsperson production still predominates With third world movements which since the sixties have pro moted a re thinking of the concept of technological develop ment promoted by industrialized countries a process of rescue experimentation and implementation of technology has begun which has as its first criteria social economic utility Given its high efficiency and its nature as craftsperson technology the chain pump formed part of this technological regeneration which is currently more commonly known as Appropriate Technology and in Latin America as Popular Technology Old chain pump models were changed with the introduction of modem materials at the same time overcoming limitations in the tecriiulogy Beginning in the seventies the pump became known according to different languages as the bomba de cuer da rope pump pompe a corde In Latin America the name was adapted to use the common words for rope mecate in Nic aragua lazo in Guatemala soga in Peru etc The modernized version of the chain pump appeared in the majority of third world countries but generally with little success Its introduction in Nicaragua on the contrary initiated a dynamic process of creative alternative models which continues broadening 1 3 The rope pump in Nicaragua The rope pump s history in Nicaragua demonstrates that those typically considered
120. ing rock and stabilizing stone are used indifferently they are indeed interchangeable v Page 124 last paragraph last line called should read called o v Page 127 figure 7 2 valld for 0 4 mm should read valid ford 0 4 mm y Page 128 figure 7 6 valid for 0 4 mm should read valid ford 0 4 mm J Page 130 line 3 the 1 4 protection tube should read the 3 4 protection tube V Page 154 last paragraph iine 3 with a 10 should read with a spanner 10 j Page 155 first paragraph line 2 photos and should read photos 23 and 24 v Page 155 first paragraph line 7 10 should read spanner 10 v Page 210 figure A 9 line 3 values 0 2 mm should read values 0 2 mm J Page 210 first paragraph line 5 water up should read water up t J Page 210 first paragraph line 5 water downwards should read water downwards J Page 211 equation 4 should read Po P2 Po Pi Pi Pz 0 X g X Hops N m 4 J Page 213 first paragraph line 6 Vpis 2 m s y 0 65 mm or Vpis 1 4 m s and 1 1 mm should read Vpis 2 m s and 0 65 mm or Vps 1 4 m s and d 1 1 mm J Rope Pump 3 V Page 213 paragraph 2 line 3 hyd model hyd real should read hyd modai Y hyd roal Page 213 paragraph 3 line 3 tub 71 mm pis 6
121. ions Use an insulator like the ones used in high power electrical systems installed in concrete or wood Right now almost all guides in Nicaragua are made with an insulator installed in concrete For drilled wells up to 3 the guide can be made in a round form 5 hail PVC PPE K protection rope Ar morecl uD eti i ronrope Rope Pum 7 7 CORROSION On all types of pumps there are problems with corrosion at the base and the wheel spokes Reasons e Quality of handling cleaning and painting in general is low In general users don t maintain the painting of the pumps Suggestions e Mount a piece of galvanizad pipe 3 8 or 1 2 to protect the lower parts of the pump structure e Use as much as possible galvanized materials treat the welded parts Clean thouroughly especialy the weldings and paint with anti rust and oil painting e Use non corrosive materials e j wood plastic cast iron others 8 NOISE The pumps make a noise in the blocking system and the handle Reasons e The materials mounted as brake absorption plastic tube or rubber get loose In the case of the handle in general it is not lubricated ditens the hands suggestions e Give an option to remove the brake lever children have to take more care making a stop see illustr al Lal b qpe n mm M mM IMM N i ma m i G a a e e 8 Annex 1 e
122. ired by the user even without a wrench because it is screwed together so with little ef fort it can be taken apart If the wood rots they can look for a carpenter to do the work while a pump made of iron would require the help of a welder And in some areas where one has to travel for hours or there_is no vehicular ac cess many people are not going to care enough to do that work They will just uncover the well and begin to use buckets Chapter 6 Description of the pump 115 Do you conduct maintenance training The training is sufficient because the user builds alongside us and as we go along we explain each step The construction isn t complicat ed there s only measuring to be done The installation is a practical matter In terms of maintenance the owners or the community have constructed the pumps with us so they feel capable and confident in taking them apart putting them back together and changing parts _ Who participates most in the construction and Installation and what have been the results Those that participate most in terms of construction are the men When it is time to do the installation the women become more in volved but all they have to do is observe And the women are the ones that draw the water The first model we made had its faults and we went about fixing it up adding a few things putting them on and taking them off until we had arrived at the mode we have now The experience
123. ising main and keep them from rubbing against its entrance It is essential with the guide to find the right combi nation of materials that will not wear out underneath the water rope with glaze or glass l While the guide is secured to the raising main with the inner tube the connection with the stabilizing stone is done with a galvanized wire rope or the same inner tube This stone weighs between 3 7 kg and rests at the bottom of the well It keeps the raising main from moving and guarantees a minimal distance between the opening of the tube and the bottom of the well _ 0 2m Alternative constructions We have had good experience with four types of guides hollow and solid glazed ceramic wood with an isolator and just wood In table 6 8 we present some characteristics of each option Chapter 6 Description of the pump 111 Table 6 8 Advantages and disadvantages of five types of guides 1 Isolator with Cement Resistance to Wear Resistance to Cracks Water resistance Price Production Level Years of field experience Alternatives and 2 A detailed description of their production can be found in Appendix E Alternative 3 This model consists of an isolator from electrical energy posts secured to a piece of wood Alternative 4 In addition to an isolator this guide has 2 pieces of tube embedded one connects with the raising main it is not necessary to tie it to the raisng main with the inner tube rubber s
124. issues like the pump installation and maintenance as well as problems which can arise in the field The fourth part finally describes the special models that have been developed in Nicaragua pumps in drilled wells those for high discharge rates post mounted pumps pumps with motors and with windmills We deal both with general aspects as well as some aspects of construction and installation We have tried to be as objective as possible but in order to re flect some of the enthusiasm which motivates many of the peo ple involved we have included a series of interviews The lan guage in the interviews is inevitably very Nicaraguan and it may be difficult to understand in other countries We decided however to maintain the local flavor of the language Although this book contains all the information necessary for in stallers and users of the rope pump it can probably not be di rectly understood by them We recommend in many cases the development of a pamphlet explicitly directed towards them Introduction 3 based on their educational levels cultural customs and in the specific characteristics of the pump in their region ground water tables well designs available technologies and materials etc It is important to keep in mind while reading this book that there is not just one type of rope pump In each region in each sit uation the pump can have a different design or different materi als Nor is there one implementa
125. itions The losses between the rope and the piston are not tak en into account The model was verified in 53 field tests at 4 different depths The standard deviation of the relative difference between the theoretical results and the field tests hyd model hyd real was somewhat high 10 due to measuring limitations None theless the average relative difference was only 1 3 so we accept the model as valid The only similar study that we have found in the literature is that cdragied out by Faulkner and Lambert 1990 which did tests us ing a high discharge rope pump withg ub 71 mm ghis 69 mm flat pistons and 2 4 mm Hhead 5 5 mm The results co incide with those of Heuthorst in that efficiency increases with piston speed and of less importance with the quantity of pis tons There are two differences Heuthorst found an optimum speed of around 2 m s while Faulkner found it to be around 0 7 m s This difference is explained by the water acceleration ef fects and entrance and exit losses that are relatively muchlarger gt ole 214 Appendix at lesser depths Faulkner and Lambert also found a slight drop in efficiency at greater depths a phenomenon that Heuthorst did not encounter in his tests We do not have an explanation for this discrepancy What does stand out is the great differ ence in pumping heads 5 5 m versus 32 m Moreover the quantity of pistons that is found simultaneously inside the rais ing mai
126. meters of 18 or 20 fastening wire a pulley wheel of appropriate diameter 4 meters of 1 x 4 wood for the mold of the manhole and the base for the outlet spout 3 meters of 1 x 1 wood for the mold of the border of the man hole 3 meters of 1 x 2 wood for the manhole cover mold approximately 25 2 nails if the pouring area is dirt approximately 12 1 stakes 300 mm high if the pouring area is paved 10 2 5 kilo rocks 100 mm PVC delivery tubing The diameter of the tube should be bigger than the outlet spout tube see table 6 6 450 mm of 1 PVC protector tube any kind of material that can protect the fresh slab from the sun banana leaves old newspapers plastic Chapter 8 Installation in hand dug wells 135 Photo 20 Putting together the well slab The mok for the slab consists of a band of zinc held in place by rocks Observe the manhole the anchor tube for the raising main the protection tube the iron rods fastening the outlet spout Photo 21 Cast well slab The same slab shown in the pho to at left The pulley whose only purpose was to put in place the anchor tube and the protection tube is now gone The protection tube with its flare is seen Papay Step by step instructions lt is important not to work alone but to organize the tasks in such a way as to involve as many people as possible men women and children This is not only to make the work easier and faster but
127. mp s true hydraulic efficiency If the values are very different the curves will be more or less steep and the calculations in an nex 7 would need to be consulted However in the majority of cases it is not important to Know the precise hydraulic efficiency Another factor that must be taken into account is that as the months go by the pistons wear out increasing play and affect ing efficiency Depending on use we recommend changing the pistons every year or two but if high efficiency is required they can be changed more frequently With the information discussed in this chapter pumps for all common applications can be selected and designed In other cases for example for very deep wells for very dig or very small wheels etc it would be important to refer to the calcula tions shown in annexes F and G Photo 19 overleaf A job for everyone Pump installation over a drilled well Note the 1 2 raising main on the left and the 3 4 protection tube on the right El Po chote _ Sed Installation operation and management Trust only those who stand to lose as much as you do when things go wrong Chapter 8 Installation in hand dug wells In this chapter we give a detailed description of how to install a rope pump in hand dug wells with a concrete slab like that which is being used in the DAR in Region V in Nicaragua This type of slab and pump is only one example there are many pos sible alternati
128. mplies less efficiency Force exerted on blocking system tension on rope and intensity of friction between rope and pulley wheel increase significantly with well depth Chapter 7 Mechanical and Hydraulic Characteristics 123 7 3 Hydraulic and mechanical efficiency Compared to other hand pumps the efficiency of rope pumps is quite high Optimizing efficiency is especially important in very deep wells and for irrigation applications Understanding the factors that influence hydraulic and mechanical efficiency is es sential in order to be able to give these aspects the necessary attention in the design and production phases The total efficiency of the pump ranges from 60 to 90 a very high percentage for hand pumps High efficiency is particu larly important in deep wells where the pumping of water implies serious work In wells with a pumping head of 35 or 40 meters the deepest wells in which we ve installed rope pumps the ef ficiency is still very high and it is only a question of testing the pump in even deeper wells to see whether the same efficiency holds up The only reason this hasn t been done is because there aren t any deeper wells in the region Next let s analyze efficiency the total efflclency of a pump Is the product of hydraulic efficiency multiplied by mechanical efficiency 124 Second part Construction Mechanical efficlency is calculated as the loss of friction be tween the pistons tubes and
129. n and fasten the two tall iron rod U s to the frame These will serve to secure the outlet spout Make the mold for the manhole cover and brace the frame Sift half a bucket of sand to be used later for the surface tex turing Make a mixture of 3 buckets of gravel 3 of sand and 1 of ce ment Thoroughly wet the frame and pour the slab As the con crete fills the frame take out the stakes or rocks Make sure the water and protector tubes stay in their correct and upright posi tion The thickness of the slab should be 50 to 60 mm Don t fill the mold with cement all the way up to the full height of the sheetmetal strip Let the mixture dry about 10 minutes then po sition the frame for the manhole nm and the frame for the base of the outlet spout on the moist mixture and fill them Wet the frame of the manhole cover and pour it Make a mixture of half a bucket of sifted sana and bucket of cement for the surface texturing Protect the siabs from the sun and the wind After three hours flood the slab with water filling the extra 15 25 mm of the sheetmetal mold If this is not possible make sure someone is able to wet the slab at least 6 times a day for curing 8 2 Installation of the pump One week after the slab is pour we can begin to install the pump But the first thing we must do is guarantee the following conditions tools and materials Chapter 8 Installation in hand dug wells 141 Conditi
130. n in Heuthorst varies from 5 to 30 while the variation found by Faulkner and Lambert is only 1 to 5 Appendix 215 Appendix H Materials for the wheel on the post Part No Material MM Quant 1 Anchor Gi 11 4 Tube 150 1 2 Post Gi 11 2 Tube 6 000 1 3 Ladder Iron 430 9 4 Raising main securing iron 1 4 400 3 5 Discharge tube securing Iron 1 4 100 3 7 Strut 12 Wire 12 000 3 6 Strut securing Iron 1 4 40 3 8 Spoke iron 1 4 190 16 9 Pulley wheel support iron 1 4 80 16 10 Pulley wheel 15 Tire 1 11 Support Iron 1 2 800 2 12 Axle 1 2 Tube 400 1 13 Bearing conjunction 2 Materials total Material MM Unit 1 1 2 Tube 6 000 1 1 4 Tube 150 1 2 Tube 400 1 2 iron 1 600 3 8 iron 3 870 1 4 iron 5 940 12 Wire 36 000 15 Old tire 1 Bearing conjunction 2 216 yas Appendix Appendix f Fhandle Fhandle teor g Hhead Hpis handle rope pis pul tub Pin Psal Qdrag Qloss Qpres Qreal Qteor Vpis VOLrev hyd rope 217 List of symbols s 1 Frequency of axle revolutions 0 5 1 N Real force on wheel handle Fhandle teor ropa N Force on pulley wheel handle without friction m s2 Gravity acceleration 9 81 m Pumping head m Distance between pistons 2 mm Diameter mm Pulley wheel handle diameter 500 mm Rope diameter 5 mm Piston diameter mm Pulley wheel diameter mm Raising main diameter W input power developed by user 30 150 W _ Exit power resulting in pumped water m3 s
131. n the rope shop or in the market and the PVC tubing in the factory Although the metal wheel has been standardized to a maximum level it still contains six different iron semi manufactured inputs apart from the old tire welding and paint For the user built pump the situation is a bit simpler but not much Although there are not many sub products it is a ques tion of finding all the materials without exception for the cover and the wheel construction lumber and GI tub ing fine wood for the guide an old tire for the pistons rope and PVC tubing Chapter 4 Production 75 ignacio Lopez Perez Pump workshop How many pumps do you produce and what are the models In tarms of quantity its what we make the most of 70 rope pumps per month We are testing a rope pump with an windmill we ve already in Stalled it and produce two per month for drilled welis with a motor We are experimenting with a pump to pump wells dry for cleaning In terms of hand pumps it s the best because it gives the highest output for the least effort In addition it is in higher demand because not every one has electricity It has also received a surprisingly strong response What have you done to improve the capacity of the shop and satisfy the demand With the increase in demand we have had to make special moids in or det to decrease person hours because we have a social commitment to reduce the costs of production We
132. nds a 46 First part The challenge of popular technology high social and technological level on the part of the promoters Even so the technical possibilities are limited preventing the rope pump s use at depths greater than 20 meters At any rate we consider essential discussion and understanding of all as pects of the rope pump by its promoters and makers artisans 2 8 Technical theoretical concepts Up to this point we have only touched on cultural and socio economic aspects of the rope pump technology There are also fundamental technical considerations that favor the basic rope pump concept To explain these we make a comparison with reciprocating plunger pumps The great majority of hand pumps are of the reciprocating plun ger type They have a cylinder hanging on raising main A pis ton moves in the cylinder driven by the pump rod The weight of the water column rests one moment on the piston sustained by the sounding line and the next moment on the foot valve sustained by the raising main in continual alteration This dy namic load combined with the shock due to the accelerations 2 implies fatigue and creep for the sounding line and the rais ing main especially in the pipe threads even more so if these pieces are made of some kind of plastic These problems occur more in pumping heads of more than 40 meters Because of the reiative elasticity of the plastic matenals the system can easily begin oscillations a
133. nduct business One now knows that wa ter can be eas ily obtained in thehome and the important thing is that there be an abundance of water easily obtained and economical With this pump you don t need electricity You don t need anything ex cept maybe a litle food to give you Poo 10 1 prefer the one make mysel strength Don Ramon Jimenez with his home made wood en pump Note that he didn t use the central rim of the tires but only the tread and walls The out let spout is a folded sheet of galvanized roofing San Patricio 28 First part The challenge of popular technology Photo 4 Will k really work The whole family participates in the construction of the pump whether is be as carpenter or observer User builder workshop given by Wilian in the white shirt promoter from Puente de Paz El Brasil through promoters or if it is enough to just see a sample pump or read an article or flyer wntten communication Another dif ference is how many and which parts and or tools are bought or produced by the users themselves The tubing is always bought but there are variations in pistons and guides Another related aspect is that there are not only grass roots in novations but there are also mistakes For this it would be in teresting to do follow up which promotes precise communica tion to accumulate experiences and avoid repitition of errors The great a
134. ng At least at the end of each month or sometimes every 22 days go visit the pumps But it s a lot of work for me and am Just a promoter nothing more visit a lot of communities in addition there are communities such as those in Serrano in which have 6 pumps to install during the next month For me alone it s a lot of work but every 22 days make a run through at least Jerusalen In El Almendro checked out the pumps we installed for the bank and all are functioning Is there satisfaction In this kind of work In my opinion the most unpleasant aspect is that we are a tiny business but we are not part of the government and it isn t up to us to go around looking for and talking to the people about bettering their health conditions and making latrines It isn t our job All of that is the State institutions responsibility But in reality from what have seen the institutions are not interested Well I ve seen that and it makes me truly sad My greatest satisfaction is that with the use of the pumps have seen an improvement in health That is the principal factor for me that all the children are drinking clean water because the well is kept sealed chlorinated and they will no longer have the problem of putting a dirty bucket or dirty hands in the well they simply tum the crank and draw up water When we first arrive at the site there are cases in which one finds cockroaches in the well So when we do
135. ng 100 mm at either end burn the ends and braid them together l Grease the bearings and make sure they are correctly posi tioned Make sure the bearing halves are in pairs and that the lower bearing half isnt the same as the upper one see figure 8 8 and photos 23 and 24 Insert the bolt without tightening the nut very much Screw on the lock nut Do a test pumping At first there will be a lot of friction between the pistons and the tubes due to whatever dirt there may be in the tubes If the friction doesnt disappear after pumping a few buckets of water take out the tubing and look for where the pis tons are hitting against the tube Once everyone has tried the pump it s good to untie the knot and iet the rope fall as if by accident into the well so that the new owners and users can take apart the pump retrieve the Chapter 8 Installation in hand dug wells 151 rope and put it back together again At first they may be afraid but in about ten minutes they will feel confident that they can handle this part of the operation of the pump Put on the rope and wheel protection Seal the slab onto the rim with a mix of cement and sand Place the manhole cover over the manhole and seal it hermeti cally with a mixture of lime and water This mixture allows the cover to be re opened if the pump ever needs to be taken apart Disinfect the well with bleach using the correct amount of bieach Make sure not to t
136. ng that goes one s likes are influenced by what one sees Perhaps the rural farmworker is not going to un derstand the technology in depth such as the technical explanation of the pump but he sees a pump functioning and it gets his attention Hey what is this all about and how does the water come out with the rope He begins to get curious and wants to know more And then this doesn t get the attention of just the man or the child but of the women as well who say I can see how it is easier and how it will make it easier for me aS a woman and for my child to obtain water can see that they view the pump as attractive simple and more dasily operated Humberto Compared to the other pumps if you are going to tell a woman what is the first thing to go on a traditional pump you could mention thousands of things that are going to go First it might be the washers it might be that the sounding rod falls apart that the rec tangular rod breaks many things can break So when you talk about these things with the women they don t pay attention and they back off saying This is a subject for the men When they ask What is it that breaks the fastest with this pump and we tell them that it is the rope and show them how to change 54 First part The challenge of popular technology that rope and make the washers then they say Ahhhh that we can do no problem and so the women feel they have more of
137. no organization is directing resources specifically towards pump research and development Consequently any research carried out responds only to the necessities of a partic ular organization at a certain moment in an ad hoc manner with no medium or long term planning 82 First part The challenge of popular technology Another related aspect is that the possible applications of the rope pump cover different fields the provision of drinking water through public weils use of private wells use of water for cattle for irrigation on a small scale etc All of these fields have been traditionally attended to by different organizations Although for each application the problems are different in technical aspects as much as in the methodology of implementation it is not rec ommended that a different organization dedicate itself to each area However in Nicaragua today no multi disciplinary organi zation exists that could attend to all of the above mentioned fields For these two reasons it is difficult to predict how and where re search will develop in the coming years In general we can define some areas of interest which we believe should be prioritized AS regards the model implemented by the DAR Region V that is amply described in the second part the necessity and possi bility of improving certain elements should be studied in particu lar the blockage system For communal wells with more users and less social control
138. nted rope pump The pump can draw water up to 8 meters above ground level One can see the post with tension wires the water raising main and the outlet spout which descends before heading towards the photographer The rope hangs unhindered from the upper pulley winds almost completely around the pulley wheel and enters the protection pipe through the upper guide Santo To mas Special Models Other people s tools only work in other people s gardens f Up to this point we have only discussed rope pumps installed in hand dug wells However the principle of the rope pump is that it can be adapted for a variety of specific uses not only for pumping drinking water but also for production applications In this last section we describe five special rope pump models in drilled wells on posts for high discharge with a motor with a windmill For each mode we discuss the issues involved its capacity a description of the model and experences and perspectives We feel that the first three models are sufficiently developed so that they can be used without much problem For these we de scribe their construction and installation similar to that de scribed in sections two and three Construction and Installa tion Operation and Management if you are not directly involved in these activities you can skip the corresponding sections Chapter 11 Rope pumps in drilled wells 165 Chapter 1
139. ntire raising main functions as a a very long cylinder in which the pistons move in just one direction At the top the raising main is connected to the discharge spout and through a T joint the pumped water is diverted to the users bucket The outlet has a larger diameter to permit the water to be diverted around the pistons and not overflow from the top The weight of the water column exerts force on the pistons these on the rope and this transmits by friction the force on the pulley wheel When finished pumping the pulley wheel and the handle turn back in the opposite direction of the pumping with the weight of the water column At depths greater than ten me Chapter 6 Description of the pump 89 ters a blockage system is needed to prevent the pulley wheel handle from hitting the users and the loss of the entire water col umn Therefore the next user should not have to again fill the entire raising main as long as the water has not been lost through the leakage that always exists between the pistons and the raising main This finishes the general description of the pump along with its functioning In the rest of the chapter we describe all of the pieces of the pump part by part Figure 6 2 Concrete well slab 90 second part Construction 6 2 The well slab Figure 6 2 demonstrates the well slab of the well it is a slab of iron reinforced concrete of 1 4 3 8 if the diameter is greater than 1 2 m The pump support is
140. ny part of this book can be copied reproduced or adapted to be more useful in projects without requesting authors permission on the condition that the sections used be distributed free or at cost and with out profit naming the source For any commercial use written permission from the authors is necessary We would appreciate it if copies of any material using part of this book could be sent to us at the following address DAR Region V A P 24 Juigalpa Nicaragua The rope pump The challenge of popular technology Bernard van Hermert Osmundo Solis Orozco Jan Haemhouts Orlando Amador Galiz participated in this book s production as well as all of those who offered information suggestions criticisms corrections and photos er ert eae i LIBRARY INTERNATIONAL REFERENCE nTRE FOR COMMUNITY WATER SUPFLY I oA CAI UAIR IN IRC ooa Rax G 12A 2509 AD The Hague 4 070 gi 4911 ext 141 142 PNE VVN WO 3y o QBER qa RO aa dy gt The development and distribution of the rope pump in Nicara gua has taken many years with various organizations and many people participating in the process The combination of these efforts has made the rope pump what it is today Although it fell to me to gather all the experiences and reflect them in this book in no way claim to be the author of the pump On the contrary therefore dedicate this book to all those who contributed and continue contributing
141. o be looking for the people that know how to install the system The pistons don t have much life and with so many people coming to get water don t Know what kind of system It could use because It has no resistance And when t stops working the people com remove the covers and take out the water with buckets because the system doesn t last long 22 First part The challenge of popular technology Not functioning Broken guide production fault 303 3 p Without rope es Coe ao A Woe cae AN Ww wo N E NS N NY N gt RS te ik NN WSS Sk S kA yy VAi Functioning 7 Figure 1 9 Conditlon of rope pumps installed In Blueflelds An evaluation of 88 rope pumps two years after emergency instal lations Source Solis O 1990 The work included the development of various models including the motorized pump and the double handle for drilled wells up to 70 meters the serial production of ceramic guides using innova tions from the Santa Cruz peasants the current design of pis tons and the organization of low cost production After the disaster caused by Hurricane Joan INAA decided to install 300 rope pumps in Bluefields as an emergency measure This was the first large scale implementation Its emergency nature it created senous difficulties technical problems given that the product was not well tested and lack of quality control and social problems because of lack of training and community par
142. o go in one direction but not in the other The lever is covered with a hose or inner tube to absorb shocks and lower the noise level that bothers users One weakness of the design is that it Is Immoving given that it is welded to the support structure which is embedded When a problem arises there is no easy solution The pulley wheel protector is optional It is made of sheet metal and rests on two iron 1 4 supports Its function is princi pally to protect the rope and the pistons from the UV rays of the sun from the dirty hands of the users girls and in some meas ure protection from vandalism Before considering some construction alternatives we empha size the following the wheel as it is described here and demon strated in the plans is made by two small enterprises with the most common and cheapest materials in Nicaragua The de sign can be adapted without any problem to other materials if these are the most common The sharp curves can also be changed by different constructions using welding e g in the pul ley wheel handle the feet If the typical design presented in this book is abandoned with all of its variants described an infinite number of very different de Second part Construction Chapter 6 Description of the pump 95 protector a ee ee 96 Second part Construction clk wte a Rope Pump How to cut an old tlre ee OE meen E Chapter 6 Description of the pump 97
143. of acceleration shocks This situa tion implies that we can pump from great pumping heads with simple PVC tubes Only the rope has to be strengthened which is no technical problem The mechanical losses are minimal which implies much greater efficiency than with the plunger pumps The circular movement of the rope pump s handle is much easier for the user than the tit of a lever Ergonomics tells us that one can develop much more potential with a circular movement than with the up and down movement of a lever with which we are familiar from tradi tional pumps There are then two reasons why the rope pump pumps more water than the plunger pumps it is more efficient and it is more ergonomically adapted 48 i First part The challenge of popular technology The reduced load on the parts under water and the absence of threads makes possible the use of non metallic materials ard Llus ef greater depth without the danger of drag And since the rope pump does not use any metal parts below water there is no problem of corrosion is this cntical zone With these technicaltheoretical considerations we conclude this chapter on the different basic concepts of the rope pump Chapter 3 Rope pump characteristics 49 Chapter 3 Rope pump characteristics In this chapter we present the technical characteristics of operation and management reliability discharge rates pumping heads and efficiency rates water quality control and c
144. of the slab 8 2 Installation of the pump Maintenance 9 1 Maintenance planning 9 2 Maintenance tasks Trouble shooting Part IV Special Models Rope pump in drilled wells 11 1 Description 11 2 Installation Post mounted rope pumps 12 1 Description 12 2 Installation 87 90 92 102 110 112 116 119 123 133 140 152 153 157 166 168 172 173 13 High discharge rate rope pumps 177 14 Motor driven rope pumps 179 15 Rope pumps with windmills 181 Appendix A Calculating maintenance costs 184 Appendix B Materials tools gauges and molds 188 Appendix C Materials for the pulley wheel in hand dug wells 190 Appendix D Specifications of PP and PE injected pistons 195 Appendix E Specifications of the glazed ceramic guides 197 Appendix F Calculating pulley wheel and raising main diameters 204 Appendix G Calculating hydraulic efficiency 209 Appendix H Materials for the pulley wheel onthe post 215 List of symbols 217 List of Abbreviations 218 Consulted bibliography 218 Addresses 220 List of Figures Figure 1 0 Global sketch of the rope pump 6 Figure 1 1 Shaduf 9 Figure 1 2 Noria 9 Figure 1 3 Noria with chain 10 Figure 1 4 Chain pump 10 Figure 1 5 Rope pump 11 Figure 1 6 The next step 11 Figure 1 7 Condition of rope pumps installed in Bluefields 22 Figure 1 8 Hourly discharge rate in the El Pochote hand drilled well 15 Figure 1 9 Rope pumps installed in Nicaragua 24 Figure 3
145. of well slabs 1 2 3 Construction ease Construction time and installation 8 wkhrs Protection of well Ease of dismantling Weight 150 kg Useful life 20 yrs Price of materials 10 00 Production level home ocal Years of field experience 3 yrs The first price reflects the purchase of the wood at market price the second does not take into account the wood s value It is very common in the countryside to simply cut down a few beams when one needs them Alternative 1 The making of the well slab from concrete re quires some knowledge of masonry as well as a week of cur ing 92 Second part Construction 6 3 The pulley wheel The pulley wheel see figure 6 3 and Appendix C is made up of the support structure the axle with the pulley wheel and the pulley whee handle and the blockage system It is the most complex piece it contains all the moving parts and is subjected to the greatest concentration of forces The axle made of a galvanized iron pipe of 1 2 or of 3 4 forms one single piece with the pulley wheel handle at one ex treme and the pulley wheel at the other In section 7 1 we ex plain why the height of the axle should be between 800 and 900 mm and the radius of the pulley wheel handle between 250 and 300 mm Since the support structure is embedded in the concrete it is important that the moving parts are easily moved This is why the axle rotates in two split bearlngs which are replaceable wit
146. on of women the resulting social changes and the rejection of technological dependence The detractors accuse it of demagoguery of being populist and strengthening negative pater nalism And finally the calmest of these maintain that it is econom ically impractical One positive aspect of these discussions is that they have contributed to the distribution of the rope pumps think that it has had some technological success in the manner in which it was introduced and believe that it has promoted modern ization but not socio economic development in terms of rural well being nutrition community and national integration and no notable changes stemming from its innovative style have come about The pump as with any other technology based on inanimate objects does not have the ability to succeed or fail in and of itself It re quires the stimulus support and enthusiasm of individuals to give it life It has been demonstrated in practical terms that any form of rope pump construction is successful if itis accompanied by a pro gram of self generated organization within the communities The success of the rope pump relies on the manner in which it is introduced Into a marginalized community with the only resource being the community s desire to participate within a group project because the process must involve a program based on the commu nity s social organization and self management The only metho dology that results
147. on the new one pull it in the opposite direction so that it doesn t pull up water and it s easy to take out If regular maintenance is done the pump can last up to 10 years although it will be necessary to replace some of the ma jor parts In annex A we show a sample calendar of maintenance activi ties This calendar is only a guide A lot depends on the quality and the kind of rope pistons guide paint and wheel In the two calendars shown one for a home made pump and one for a technified pump two factors are taken into account the pumping head and the amount of water pumped Chapter 9 Maintenance 153 9 2 Maintenance Tasks Here we describe the most common maintenance tasks They are listed in descending order of ocurrence We don t go into de tail when the procedures are similar to those used in the installa tion since they are described in section 8 2 Changing the rope Depending on the protection of the pulley wheel the use of the pump and the quality of the guide the rope should be changed every once in a while It is best and easiest to do this before the rope breaks It is easiest to change the pistons at the same time you change the rope even if the pistons are not yet worn out they can be saved to be used for the next time you change the rope Tie the new rope with the pistons attached to the old rope be careful with the direction of the pistons pass it through the tubing and when it come
148. ons a well that has been washed with its nm at a height of approxi mately 300 mm and the poured slab cured for a week at least 6 strong people to position the slab on the rim For the installation at least two people preferably the new owner or some of the users are needed Necessary materials raising main as long as the depth of the well As we described in section 6 4 it is essential that the entire raising main be of the same brand and schedule any difference in diameter in the tubing can cause serious problems for the pistons outlet spout tube reducer T connector elbow connector and approximately 1 meter of outlet tubing See table 6 6 for dimen sions a guide rope two times the length of the well plus 2 meters plus 5 for the knots sufficlent number of pistons one for each meter of pumping head rubber inner tube strips of more or less 30 mm wide for 2 me ters total a stabilizing rock 2 7 kilos more or less square cement blocks work well but not in acidic water they will dissolve in a few months a bit of grease to lubricate the bearings Optional materials half a bucket of sifted sand 1 6 bucket of cement 1 kilo of lime wheel protector Dleach to disinfect the well 142 Third part Installation operation and management Necessary tools adjustable or fixed wrench for the security bolts of the bearings knife pliers
149. or high discharges and post mounted do not need to be improved at the moment Howev er frequent monitoring would be appropriate The motor driven rope pump functions in a satisfactory manner for wells that are relatively shallow It would be impor tant to widen the functioning area and look for its limits for example to what depth can pumping be done from a drilled well Frequent monitoring would also be important At the present time the Rope pump society is involved in this work In the rope pump with a windmill complete development is still lacking in the construction field in the study of volumes pumped according to the wind speed the demands for irriga tion and or drinking water and economic feasibility studies before thinking of implementing it Ignacio Lopez workshop is involved in the technical development of the windmill With these perspectives regarding the future we conclude the first part which is the general part of the book In the second part we will enter into construction details of the pump Photo 14 overleaf User built pump Note the use of only local materials The use of the container as the outlet spout is interesting Chinandega Construction If you consult enough experts you can confirm any opinion Second part Construction 86 wt i E A ANN VERAT A SESS SE a ee oe 7 2 PA META fe E S aF SS Sys OTTE T AZ a TITTA N a Sen
150. osses For this we define the exit loss factor Kw 2 2 E pls ropa S g oF tub pls 7 K s i e P P Sloss Nim2 8 1 2 2 3 2 g d Dab sis We have now defined a system of 4 equations equations 3 4 5 and 8 with 4 unknowns PO P1 P1 P2 Qloss and Qpres This system can be resolved manually although it demands perserverance or numerically with a microcomputer Some results are reflected in the figures 7 1 7 3 Discussion of the model s validity The model presented here starts with the following premises The tube has a constant interior diameter All the pis tons are of equal form and diameter and are equidistant F Calculating hydraulic efficiency 213 There are neither entrance nor exit effects The flow through the ring between the piston and the tube wall is laminated Reynolds number less than 2 300 This limits the applicability of the model to cases where neither the speed nor the motion are very great For example the following combinations Vpis 2 m s gt 0 65 mm or Vpis 41 4 m s and 1 1 mm We have not discarded the model for other cases but neither has it been proved Likely the real losses would be greater than those calculated in the model Also neglected are the dynamic effects of the water flow such as the acceleration of water and the friction be tween the water and the tube This is acceptable be cause it is less than 1 in our cond
151. osts Given that the use of quantitative data cannot be avoided we use two typical models as an example the technified model which has been implemented by the DAR Region V and is amp ly described in the second part with an iron wheel concrete slab polyethylene injected pistons PE and a glazed ceramic guide and the user built mode with a wooden wheel wood en guide with rubber pistons 3 1 Operation and management The rope pump is excellent for operation and maintenance at the local level or by the owner This has been proven in prac tice Even in the cases where there has not been much empha sis on maintenance issues during implementation we have no ticed a regular state of maintenance of the pump in the majority of cases one example is the case of Bluefields figure 1 8 This is even more true if users have gone through a real transference of technology It is not surprising that in these cases it takes lit tle for them to carry out adequate pump maintenance Basically maintenance is limited to a weekly oiling of the bear ings Two pieces are continually being worn down and need to be changed once or twice a year the rope and the pistons 50 First part The challenge of popular technology In Appendix A we estimate the useful life and we calculate the monthly cost given different conditions for use In table 3 1 we give a summary Table 3 2 illlustrates the useful life in a typical case Table 3 1 Maintenan
152. ouch the pump while the mixture is drying During the first few hours of operation the rope and knots will stretch some and it may be necessary to shorten the rope a little by cutting it Now that we ve seen how easy it is to install a rope pump we can go on to look at the pump s operation and maintenance both of which are in fact technically simpler than the installa tion They do however require careful attention 152 Third part Installation operation and management Chapter 9 Maintenance In this chapter we will first analyze maintenance planning and then give a brief description of the various maintainance tasks 9 1 Maintenance Planning As with anything that has moving parts regular maintenance is necessary to keep it in good running order and for it to last a long time Preventative malntenance is always better than corrective maintenance preventative maintenance can be planned and scheduled according to the users convenience it is less work and it helps avoid down time of the pump while you look for or make replacement parts Don Ponpilio a veteran with these pumps gives the following advice to his clients As i explained in order for the pump to work well the users should be careful and fix it before it breaks down The rope is worn out Change it Explain how to change it have the rope and the pistons beforehand and it can be replaced without having to take out the pipe Just loosen the rope tie
153. ounted pumps 173 Table A 1 Materials tools and gauges to construct the technified pump 185 Table A 2 Materials tools and gauges to construct the user built pump 185 Table A 3 Recommended pulley wheel and raising main diameters 186 Photo List Photo 1 A developing technology Photo 2 Children pumping Photo 3 One of the pioneers Don Pompilio with his wife and grandson Photo 4 Will it really work Photo 5 Water to drink to wash clothes to bathe Photo 6 Women are the primary users of the pump Photo 7 The pump in the main room Photo 8 Our commission is made up only of women Photo 9 Local production Photo 10 1 prefer the one make Photo 11 Serial wheel production Photo 12 Injector machine Photo 13 and after Photo 14 Self ouilt pump Photo 15 Blocking system used in Region V pump Photo 16 Alternative blocking system Photo 17 Making rubber washers Photo 18 Why so high Photo 19 Everyone can participate Photo 20 Slab frame Photo 21 Poured slab Photo 22 Bad location of a protecting tube Photo 23 Well located bearings Photo 24 Badly located bearings Photo 25 Cracked raising main Photo 26 Rope in the pulley wheel Photo 27 Rope pump on a post Photo 28 Pump in a drilled well Photo 29 Pump on a post Photo 30 Pump for high discharge rates Photo 31 Pump with fixed windmill Photo 32 Pump with moving windmill Photo 33 Post mounted pump Photo 34 Piston gauges Photo 35 Cinv
154. ous work In pumps with a pumping head of 35 40 meters which are the deepest in which we have installed the rope pump the efficiency is still good The total efficlency of a pump is the product of the hydraulic efficiency multiplied by the mechanical efficiency Mechanical efficiency consists of the friction losses between the different moving parts of the pump It is difficult to establish the mechanical efficiency by testing but we can estimate it based on experiences in the field as between 80 90 As ex plained in section 2 8 the mechanical losses of a rope pump are less in principle than those of a reciprocating plunger pump The hydraulic efficiency rate consists of the leakage of water through the narrow ring that exists inevitably between the piston and the wall of the raising main This efficiency rate is easy to measure and field tests demonstrate that it varies between 80 and 95 The hydraulic efficiency rate depends on various pro duction factors principally the play between the piston and the raising main and the piston s velocity The dependency of these two factors is demonstrated in figure 3 3 Chapter 3 Rope pump characteristics 63 performance area of the DAR pump x a Q E D 2 5 a B D m L e TO 2 12 _ 414 16 _ 1 8 Piston velocity m s Figure 3 3 Hydraulic efficiency Curves of the theoretical hydraulic efficiency rate of a rope pump as a function of velocity for three plays
155. p almost five minutes while the adult man can do it in a little more than 1 1 2 minutes To generate maximum power the maximum force exerted on the pulley wheel crank should be 50 120 Newtons 5 12 kilos This is if both arms are used To generate maximum power the maximum turning speed of the pulley wheel crank should be 0 7 1 revolutions per second 118 Second part Construction It is very important to take into account certain dimensions that influence how much energy a person can generate and how long it takes for him her to get tired Since the operation of the pump consists of a turning motion the ideal height of the axle should be a little higher than the av erage elbow height of the users At thisheight there is the least amount of useless movement of the rest of the body For Latin American adult women the ideal axle height is between 1 and 1 2 meters With the same goal of avoiding useless body movement the distance between the axle and the grip of the pulley wheel han die handle radius should be equal to the distance between the elbow and the center of the closed hand Again for Latin Amer ican adult women the ideal length is between 0 27 and 0 33 meters To be able to operate the pulley wheel crank with both hands the crank handle should be at least 0 3 meters long The apron should also be built in such a way that the user can easily posi tion herself In choosing these dimension
156. particularly with drilled wells a more robust and vandalism resistant model should be developed with better protection par ticularly for the rope Price is not important in these cases since a drilled well costs between 2 000 3 000 the 50 100 for a rope pump is not a signficant component At the present time the DAR Region V is working on this It would be interesting to work in the development of pumps for pumping heads above 40 meters maintaining high efficiency rates At the present time the DAR Region V isworking on this It would be important to monitor a large quantity of rope pumps regarding their useful life for different parts to be able to know how to improve the design as well as to Know the require ments for maintenance and the useful life of the pump in partic Chapter 5 Future Perspectives 83 ular for the blockage system and the different types of pistons and guides It would be important to more systematically research the pro tection the rope pump provides against possible contamination of well water and the possible measures to improve this protec tion if necessary To attain the highest efficiency rate of the pump particularly for great depth and in the long term the wear on the injected pistons of different flexible materials soft PVC rubber that per mit less play should be investigated As regards the special models described in the fourth part The models for drilled wells f
157. pe That was it It took us three and a half days to make it Sometimes things went wrong and that set us back somewhat maybe we made the pulley wheel frame incor rectly and then had to make it over again In the magazine they explained how to make the washers with a Knife We made a punch from galvanized tube and sharpened it We put the tire on a block and hit the punch with a mallet and in this way we cut the washers What you need Is to have at least some idea of what you are doing and where there is a will there is a way Just a little idea nothing more an idea of how it might function bet ter and not malfunction What do you have to say regarding purchasing a pump made In a workshop Well sure a pump made of iron is going to last longer because we are dealing with iron but it is also going to cost more prefer the one make myself for economic reasons because try to do it in the least expensive way possible with whatever have at hand With the pumps made in the workshop the builder includes all his her ex penses and can t charge one peso less But not with mine look around to see if might not make it with a little piece of old rope until have enough money to buy a new one That s the way made the pump and now have water Chapter 1 A developing technology 27 Water is the most important thing needed in the home in order for one to feel comfort able when go ing out to do a job or co
158. pe of pump installed in the region Note The great majority of these rope pumps did not have any protection for the pulley wheel In the discussion regarding the protection of water quality anoth er factor must be taken into account the reliability of the pump A pump that provides good water quality protection is of little value if the pump is not reliable most of the time the users will 66 First part The challenge of popular technology be taking water from the well with a bucket on a rope It is also important to keep in mind that every time a well is opened there Is a possibility of contamination which means that the well needs to be chlorinated before closing it If this is not done ade quately the water quality could be affected Humberto a coordinator of promoters does not leave any doubt We cannot install something with which the community will have the same water problems tomorrow they will have no way to take out the water and they begin to drop buckets into the well and in a short time the situation will be the same as be fore even worse because the water is more concentrated with microbes there is no circulation and more iliness is generated in the community with all these broken pumps that we will have Another aspect in the study is that we have only looked at the wells in good condition leaving aside nearly 60 of the wells with imperfections in construction location or maintenance It does not m
159. plicity of the structure is such that this model could be very interesting One potential problem is the absence of a security system The second model see photo 32 does have a head that rotates on a limited angle 120 degrees which assures higher yields but also makes construction more difficult It does have a secur ity system 182 Fourth part Special Models Experiences and development Both models are in the technical development phase and it is Photo 32 Pump on a rotating windmill With a tower clearly higher than the station ary model this design has a rotating head and a security system At a distance of some 3 meters along the ground one can see the transmission as well as the pump s tubing Ignacio Lopez Workshop Managua still too early to predict their po tential scope or characteristics for example the dis charge rate ac cording to wind speed and direc tion While the concept seems in teresting both technical aspects and economic fea sibility still need to be studied With this descrip tion of the wind mill we come to the end of special models and by the same token we conclude this book about the challenges that popular technolo gy of rope pumps poses to all of our readers A Calculating maintenance costs 183 Appendix 184 Appendix Appendix A Calculating maintenance costs In this appendix we present a calendar of maintenance costs given
160. pply and sanitation projects as well as for the sale of pumps The use of the rope pump by itself does not guarantee high reliability but reliability can potentially be guaranteed when the users have been trained and are will ing No systematic monitoring in the field has been done using per centages on the pump s reliability but we can affirm on the ba sis of our observations that it is reliable Repairs are generally made within a few days If the process drags it is due to a lack of resources to buy necessary parts Frequently repairs are made by the owner or caretaker Sometimes someone is paid but it is always a community mem ber The lack of tools and technical knowledge is never mentioned as an obstacle to repairing the pump Don Emilio Miranda a member of the water committee of a communal well comments When the porcelain guide broke began to think Why can t I make this piece out of wood Why am I going to go all the way to Nueva Guinea to buy a new guide if can make it here in half a day And the one that make will probably function better that the one that they bring from Managua Thus we conclude on the basis of our observations that the rope pump is reliable 60 First part The challenge of popular technology 3 3 Discharge rates pumping heads and efficiency rates For users high water discharge is almost always of primary im portance more important than ease of movement Almost eve ryone
161. prefers working hard for a strong flow of water rather than working less but waiting longer to fill their bucket On various Acceptable Discharge rate Litres minute Unacceptable 5 10 _ 45 2 5 30 35 Pumping head Meters Mean Minimum Maximum Figure 3 2 Pumping discharge rates The lines represent the limits between the three zones defined by Arlosoroff e a 1988 The symbols summarize 53 tests done in the field executed at four wells with different users including children it can be observed that when pumping head increases the rope pump results come closer to the typical zones This is due to the following for cylinder pumps the efficiency increases with the pumping head while in the case of the rope pump it remains the same Source Heuthorst 1991 Chapter 3 Rope pump characteristics 61 occasions we had temporarily installed pumps with a greater di ameter raising main than that advised by the theoretical norms of ergonomics because of a lack of tubes or pistons with the correct measu remenits but after installing a better designed pump several weeks later according to the ergonomic parame ters the users wanted to stay with the original pump In other words we generally found that users apply a potency much higher than 100 watts However we consider that pumps with heavy action should be avoided in order to keep the pump ac cessible to women and children Arlosoroff et al 1988 define
162. raulic efficieny 02 03 04 05 ve o7 os 99 i Gap between tube and piston mm Figure 7 1 Hydraulic efficiency as a function of the gap between the pistons and the raising main tube Values valid for Hpis 2 m and Vpis 1 4 m s The second most important factor is the piston speed Vpis As can be seen in figure 7 2 if the speed drops below 0 8 me ters second m s the efficiency level drops drastically but above a velocity of 1 8 m s efficiency does not increase signifi cantly The current speed is generally limited to 1 5 m s due to the diameter of the pulley wheel maximum 540 mm that is a 20 tire and the ergonomic characteristics of a maximum turn ing speed of the crank handle of one revolution per second As we saw in the previous section we can vary the force on the pulley wheel crank handle by varying the diameters of the tube and of the pulley wheel This last variation directly affects the speed of the pistons It is therefore preferable to choose a Chapter 7 Mechanical and Hydraulic Characteristics 127 E S D 2 g iS E 1 12 14 Piston velocity Vpis m s Figure 7 2 Hydraulic efficiency as a function of piston speed Vpis Values are valid fo 0 4 mm and Hpis 2 m narrower tube and guarantee greater speed with a bigger pulley wheel than to do the opposite use a wider tube with lower speed However with the 20 tires used up until now it will be difficult to achieve th
163. rect the piston The dis tance between pistons varies between 0 5 to 5 meters depend ing on the quality of the piston For example for a piston with a play of 0 4mm we recommend maintaining approximately 2 m If the play is greater the distance between the pistons should be less 144 Third part Installation operation and management lt can also be done beforehand Widen the flare of one of the tubes using the same procedure as for the protector tube see description above Be even more careful this time because the pistons must be able to pass through smoothly Plane the inside edges of the raising main and join them with PVC glue with the flare facing down to avoid friction and wear of the pistons in the joints See figure 8 5 Make sure not to get the tubes dirty or the pistons will stick The lower tube should be the one with the wider flare Measure using the tubes the total depth of the well and cut the upper tube leaving 300 mm above the rim Secure the guide with strands of inner tube to the raising main making sure the widened flare rests in the groove of the guide See figure 8 5 Don t use more than 2 or 3 layers of inner tube as the pressure of each layer adds up and together they could deform the tube If the tube has a smaller diameter than the groove of the guide reinforce it with a nipple cut from the same tube to widen its outer diameter and at the same time reinforce it Using the fastening
164. rom rope on prston washer Figure 6 5 Forces acting on pistons vs washers The hydraulic pressure is not shown to avoid complicating the figure Notice that in the case of the piston the friction forces apply below the point of application of the force of the rope In the case of the washer the opposite occurs which provokes a lot of friction given the instability of the system rope comes out is as small as possible to minimize leakage and so that the tightness of the rope can direct the piston The dis tance between pistons varies between 0 5 to 5 meters depend ing on the quality of the piston For example for a piston witha play of 0 4mm we recommend maintaining approximately 2 m if the play is greater the distance between the pistons should be less 104 Second part Construction Through years of experience in Nicaragua the pistons have gone through a fundamental improvement process and it is pri marily this improved design which has permitted us to achieve greater efficiency rates and greater depths than other rope pumps described in literature The present pistons are made of polyethylene PE or polyepropilene PP injected 5 and has a conal form As can be seen in the figure 6 5 the washer the point of application of the friction forces and also the resulting hydraulic pressure on the piston is not show in the graphic is located at a higher point compared to the force exerted by the rope on the piston throug
165. s the ergonomic parameters the invariable parameters the variable factor that we cannot influence the pumping drop and the two variable parameters that we have at our disposi tion for optimizing the system the pulley wheel and raising main diameters The ergonomic parameters are fixed ranges that we cannot in fluence They are the following handle Pulley wheel handle diameter 500 mm Fhandle Torque on the pulley wheel handle between 50 N and 120 N Pin Input power developed by user varies from 40 W to 150 W f Frequency of axle revolution of the pulley wheel handle with a range of 0 7 1 revolution second F Calculating pulley wheel and raising main diameters 205 The invariable parameters that influence the calculation of forces are g Acceleration of gravity 9 81 m s2 rope Mechanical yield estimated at 0 8 rope Rope diameter 5 mm Pl 3 1416 Specific weight of water 1 000 kg m3 The variable factor that we cannot influence but which does guide the selection of the diameters is Hhead Pump drop m The two parameters that we can vary to optimize the system are pol Effective diameter of the pulley wheel mm and tub Real interior diameter of the raising main mm In working with these formulas we must respect the units used in this list The formula that defines the torque on the pulley wheel handle is Fhandle 1 rope pol 4
166. s it is important not only to adapt them to the average size of the users but to also take into ac count the smallest and weakest users For example a commu nity well should be designed taking children into account while an irrigation pump may possibly be used only by men The di mensions used by the DAR in Region V for community well pumps are axle height 0 8 to 0 95 meters handie radius 0 28 meters initial force 40 100 watts With this information we can calculate the amount of water a person can lift in a given amount of time and how the load and the speed of the pulley wheel handle should be selected for the Chapter 7 Mechanical and Hydraulic Characteristics 119 most efficient operation by the user On this basis in the next two sections we calculate the factors that need to be taken into account so that both the person and the pump perform as effi ciently as possible 7 2 Choosing diameters for the pulley wheel and the raising main When the pumping head is greater the weight of the water col umn is also greater In order to not increase the force required on the handle given the greater weight of the water column be ing lifted we can vary two factors the diameter of the raising main and the diameter of the pulley wheel One user Ram n Enrique experienced this very directly he problem with the pump was that it had a one inch pipe not a 3 4 and it didn t work The bigger the pistons
167. s diam eter is reduced the height between the position where the recip ient begins and finishes emptying is also reduced That is to say there is less water lifted uselessly above the discharge lev el which logically results in greater efficiency The next step in the noria s transformation was the substitution of the recipients on the chain by walls around the rising chain with plates located within these walls set at equal distances along the whole chain making the noria into a chain pump This description is similar to still existing models like irrigation canal pumping which moves large quantities of water at mini mal heights In this case the pump walls form a canal where the plates move along the chain Two pulleys sustain the chain with the upper one transferring the motor force to the chain 12 First part The challenge of popular technology The best known and developed model of the chain pump illus trated in figure 1 5 is made up of a tube instead of walls and discs or washers instead of plates In this form the chain pump had a huge impact from the 16th century to the 19th In the middie of the last century one of various uses of these pumps was as emergency pumps in transatlantic ships one ap plication which indicates the level of efficiency and reliability With the emergence of large scale industry and therefore its preponderance over artesanal production there was more se lective development of technolo
168. s good discharge rates in figure 3 2 as well as acceptable and unacceptable rates at different pumping levels Given that these discharge rates depend di rectly on strength developed by the user the graph ts not unique a strong man gets more water with the same pump than a girl The rope pump complies perfectly with the estab lished norms demonstrated in the graph particularly for shallow wells the discharge rates are much higher than required Given field experience among others the case study in El Po chote we can use table 3 3 for an overall idea of the possibili ties of a rope pump s coverage Table 3 3 Hours of Daily Pumping Number of Discharge Depth 10m 20m 30m Users m3 day Discharge 0 9 l s 0 5 V s 0 3 I s 0 5 hrs 0 9 hrs 1 4 hrs 1 2 hrs 2 7 hrs 5 0 hrs 2 5 hrs 5 0Qh hrs 7 8 hrs The daily discharge categones are taken from Arlosoroff 1988 The quantity of users is estimated based on this data assuming a consumption of 20 liters per person per day p 62 First part The challenge of popular technology The pump s efficiency is directly related to daily discharge rates Although we analyze the subject of efficiency in depth in chap ter 7 it is worth mentioning this dilemma briefly The total efficiency of the pump varies between 60 and 90 which is high for a manual pump A high efficiency rate is of particular importance in the case of deep welis where pumping water is seri
169. s out again tie it Thus it is not nec essary to take out the tubing Matenals needed new rope new or used pistons cigarette lighter matches or burning ember knife Changing pistons Pistons usually last about twice as long as the rope You can see if they need to be changed by watching and listening to how fast the water goes down the raising main when you stop pump ing The water shouldn t go down faster than 0 1 to 0 4 meters per second Make sure the new pistons you get are the same size as the used ones and that they weren t made for a different kind of tubing Since changing the pistons is done at the same time as changing the rope the procedure is the same as above 154 Third part Instaliation operation and management Paint To avoid corrosion it is essential to paint the pump structure It s not necessary to take it apart but it is important to clean it well with a steel brush and sandpaper and then wipe it off with a rag soaked in solvent Then apply one or two coats of anti corrosive paint and one or two coats of lacquer or shellac Sand lightly between each coat Materials needed 1 16 liter of anti corrosive paint 1 16 liter of lacquer or shellac solvent steel brush sandpaper small paintbrush Changing the guide It is time to change the guide when you begin to notice that the rope is wearing out faster than normal To change the guide you have to take out
170. s society sells and installs rope pumps throughout Nica ragua particularly in the country s Pacific region The society sells between 5 and 10 rope pumps weekly Moreover the society is dedicated to thetechnological develop ment of the pump and in particular im proving of the pistons and the glazed ce ramic guide the pump for a raised tank and a motorized pump Rene Mesa coordinator Henk Alberts adviser Reparto Los Cedros Cdragetera Vieja a Leon Km 29 100 v dragiba a la orilla de la cdragetera 505 2 51236 Appendix Name Description Contact Address Tel 225 Alan Gallegos Ceramic workshop that produces glazed ceramic guides molded with extruder Alan Gallegos coordinator Ron Rivera adviser Del Hotel Estrella 2 c al lago 3 c arri ba casa no 21 Managua Ron Rivera 505 2 73807 Addresses outside of Nicaragua Name Description Contact Tel Fax Name Description Address Bernard van Hemert Principal author of this book Has worked with appropriate water technolo gies and pumps since 1982 and with rope pumps since 1987 Oude Velperweg sop HE Amhem The Netherlands 31 85 61 7817 31 85 644909 Mennonite Central Committee Technology for Health CCM Tecnolog1a para la salud This NGO works in conjunction with EC OTEC in the development of the rope pump in Guatemala Although it has little experience to date its emphasis on tran
171. section 4 2 4 1 Production levels in order to discuss the feasibility of producing a piece in X or Y location we define the four technological levels of production in table 4 1 depending on the tools and materials available at each level 3 3 We have limited the discussion to the tools and materials relevant for the pump s production and for the molds but each of these tools mentioned is not always required in order to make the pump 72 First part The challenge of popular technology Table 4 1 Definition of technological levels of production Available materials and level semi manufactured inputs Production Available tools Common carpentry tools Fine wood non electric Simple Lathe for wood 110V 200W Electrical welder 1 110 V 50 A Hand wheel to make rope Steel Lathe at 220 V Slide guage Ceramic oven reaching 1 300 degrees Cinva ram Manual Extruder for PE or PP with 100 N mm2 pressure heating 110V Multiple electnc extruder for PVC Sand cement construction iron 1 4 A used tire Welding electrodes construction iron in different diameters galvanized iron pipes PE fiber for rope lron or Bronze Bar up to 50mm Stoneware Clay Feldspar PE or PP as raw material PVC as raw material Chapter 4 Production l 73 Now that the relevant characteristics of the different technologi cal levels have been identified we can analyze which piece can be produce
172. ses Solutions 1 The rope got dirty proba bly from the tube with soap oil grease or gas affecting the friction coeffiecient 2 The pulley wheel is not in enough of a V shape possi bly because the inner tube packing is too thick 4 Too much force on the rope because the pistons are Sticking 5 Too much force on the rope because the diameter of the tubing is too big 3 The rope has too much play This problem occurs more fre quently in shallow wells that have a lot of water Problem 6 1 Take out the rope and clean it with lots of soap and water 2 Change the inner tube packing or the pulley wheel if it s the pulley wheel itself it is a production defect 3 Shorten the rope by cutting it until it has a play of 100 to 200 mm Tensing the rope is not recommended it causes too much friction and wears out the guide 4 See problem 1 5 Use smaller diameter tubing for the raising main If you want to keep the same volume of water use a bigger pul ley wheel You hear an imploding sound every few tums The flow is inter mittent This only happens in deep wells Possible causes Solutions 1 Figure out which pistons are causing the problem and fix them by grinding them 1 One or more of the pis tons has a bigger diameter than the others and is working alone This pro duces a vacuum under neath the piston Photo 27 overleaf Post mou
173. sference of technology is interesting Contact Edgard Caceres director Raymundo Helmuth technical adviser Apartado Postal 1779 Ciudad de Guatemala 01901 Tel 030 4308 226 Name Description Contact Address Teol Name Description Contact Address Tel Name Description Appendix ECOTEC This organization works together with the Mennonite Central Committee in the de velopment of the rope pump in Guatema la Although it has litte experience to date its emphasis on transference of technology is interesting Bayron Rosales Amado 7a avenida 8 90 zona 2 Ciudad de Guatemala 2247 1 2487 1 DEMOTECH A small Dutch NGO that is dedicated to development and the transfer of appro priate technology It has worked for more than 10 years with user built rope pumps in many places including Indone sia and Peru It emphasizes technology transfer and user participation Reinder van Tijen coordinator A P 303 6950 AH Dieren Holanda 31 8330 15777 Center for technological advice on water pumps Centro de asesoria para bombeo de agua This center has introduced the large flow rope pump for low depths with technical and financial GTZ Germany assis tance a Rope Pump 1 Annex 1 During a technical evaluation of the 60 ropepumps Installed 2 or 3 years ago by the proyect of INAA SNV in Nueva Guinea Nicaragua some weak points were found The problems found are 1 TH
174. sures 0 1 0 3 mm less than the diame ter of the piston desired The punch is heated and without force the rubber is perforated Depending upon the time the piston remains in the punch and its temperature the rubber will burn longer This influences the final diameter of the piston A self builder Dorie has a lot of experience with these pistons This type of pistons from a rubber tire are easier to make in the field and cheaper It is not the same as making it with a hot punch or with a well sharpened knife as going to the factory to buy it It is much cheaper to make it in the community 6 Teijen 1986 mentions foam soles from sandals as piston ma terial Given its flexibility it could be an interesting option since it would minimize movement but we don t have reliable data on wear Chapter 6 Description of the pump Roughen the outside of the raising malin and the Inside of the anchor tube 1 1 4 anchor tube ee set Jn the well slab aad 109 gt Tube the same size as the raising main gt Cutat a 45 angle 6 a Pa gt Sand to produce a rough surface Round otf the outsideadge oe fay Te ie A ai ep r u eee ee 3 ae prea amp Region 0 maa dar OP Rone Pump 110 second part Construction 6 5 Guide and stabilizing rock The guide shown in figure 6 8 is another key piece of the pump Its function is to guide the rope and particularly the pis tons into the ra
175. t a certain depth increasing the ten sions and the effects of wear and tear even more In addition to these construction problems the effects of alter 2 Besselink et al 1990 has measured and calculated factors of 1 2 to 1 8 with respect to static load ee Chapter 2 Basic rope pump concepts 47 nate acceleration and deceleration both of the sounding line and of the water column limit the pump s mechanic efficiency The rope pump on the contrary has a great advantage of conti nous unidirectional circular movement There are no alternating accelerations of either the complete water column nor of the pieces This movement implies a minimizing of accelerations and static load at least in the pieces with the greatest concen tration of forces clearly the axle is subject to a dynamic load with all of its advantages in terms of less load on the parts and fewer mechanical losses The weight of the water column is uniformly distributed on the rope within the raising main be cause of the chain of pistons The raising main never has to support a pressure greater than a few meters of water column the distance between the pistons in addition to its own weight This represents a pressure of only 3 as compared with the raising main in a plunger pump at the same depth of 40 meters The only element which is subject to considerable stress is the rope and even so the load is static and much less than the sounding cord due to the lack
176. ter in a decentralized form than relatively small quantities in centralized wells although this can have a negative impact on water quality control self sufficiency in materials and knowledge both at the nation al level and at the user level when possible certain social control over the pump is necessary but this is not considered a limitation rather it guarantees interest and care by the users village level operation and management VLOM ocal production when possible and at the least national production a transfer of technology both to the producer and to the user to guarantee a foundation of technology in society and its continuous development even without outside intervention 1 500 pumps have been installed in total in both private and community wells under different implementation approaches self construction is considered a necessary phase in the pump s introduction for initial development and assimilation into the community sales at both the artisan level and the semi industrial level are responsible for the majonty of installed pumps institutional rural water supply and sanitation projects have de veloped and implemented the pump in excavated and drilled walls with good results The rope pump is inexpensive efficient and simple It has a high efficiency rate and pumps large quantities from 2 liters per second at five meters to 0 3 liters per second at 40 meters The pump is appropriate
177. the installation when we make the apron and the rim etc if the old rim is made of wood we take out the wood and make sure that the owner or the user clean out the well consider it super important that we eliminate all the creatures living inside the well and the existent dirty water leaving everything new including the water 32 First part The challenge of popular technology Photo 5 Water to drink to wash to bathe For health reasons the pump should be included as an element within an integrated sanitation system a well a cement floor a bathing area a drainage pipe for the laundry Some of these im provements were financed by Palo de Hule Jerusal n medium and long term needs This can affect not only the dura bility of the pump but also the training of users in maintenance and repair This approach is ideal for private wells especially when there are economic benefits from the water cattle irrigation One problem Is the sector with scarce resources which should be covered by a special program of subsidies and or credits Chapter 1 A developing technology 33 institutional Projects What we call institutional projects are projects generally with international funding sources which work with an integrated package of water supply basic sanitation health education and at times many more elements The rope pump is just one part of this combination of activities Generally there are communal w
178. the tubing see section lil 2 although you don t have to take the rope out of the tubing Materials needed new guide strip of rubber inner tube Tools needed knife cigarette lighter matches or burning ember Changing the bearings When you notice too much piay in the bearings they should be changed Just take the rope out of the pulley wheel without un doing the knot take out the secunity bolts with a 10 or adjusta ble wrench and change the two pairs of bearing halves The s anD Chapter 9 Maintenance 155 correct positioning of the bearing halves is very important see figure 8 8 and photos and II Materials needed s two pairs of bearing halves grease 10 or adjustable wrench dapas Changing the outlet spout When the pump is in direct sunlight the ultra violet rays will af fect the PVC outlet spout pipe causing cracks Changing the outlet spout is easy and doesn t require much explanation T connector elbow connector and outlet spout of the correct diameter Changing the raising maln if the well has loose sand the sand will affect not only the pis tons but will wear out the raising main as well Matenals needed raising main tubing strip of inner tube Logis needed knife cigarette lighter or matches smali tube of PVC glue a bottle with a neck less than 18 mm diameter saw to cut pipe Changing the wheel Within several
179. the useful life of each of the pieces of the pump At the same time we take this opportunity to detail the calculation of cost of materials for maintenance These costs do not include labor We drew up a series of tables for each rope pump prototype the technified models iron wheel PE pistons glazed ceramic guide and the user built wooden wheel rubber pistons and wooden guide The useful life is given in months the figures in bold type have been verified in the field while the normal fig ures are estimates The tables take into account two factors the quantity of water pumped daily and the pumping head 10 20 or 30 meters In terms of daily pumping we use the categories defined by Ar losoroff 1988 which are as follws 8 m3 day equivalent to 40 barrels Intensive use public well 4 m3 day equivalent to 20 barrels Normal public well 1 5 m3 day equivalent to 7 barrels Private or several family well Photo 33 overleaf Aeria pump pole The post with stairs and tension wires is clearly observed the raising main to the left and the outlet spout to the right The rope with the pistons hangs unhindered from the upper pulley Santo Tomas A Calculating maintenance costs Table A 1 Technified pump daily pumping 8 m3 Pumping head 30 m 20 m 10 m Value Life Value Life Value Life Rope Piston Paint Guide Bearings Outlet spouts Raising main Axle with pulley and pulley wheel handle
180. this temperature to let all moisture escape After all the humidity has escaped from the guides increase the temperature by 1 degree per minute until reaching 950 1 000 degrees Leave the kiln closed as it cools down to avoid thermal shock this takes about two days Glazing Obtain the glaze if you cannot find it it may be prepared A mix of 50 ground glass with 50 feldspar is preferible or if not 50 concrete volcanic lava with 50 feldspar Grindina mill and strain to a mesh of 120 holes per inch Clean the guides with a moist sponge and glaze them 200 Appendix Second Firing Since one firing has already been done the temperature can be raised rapidly according to the capacity of the kiln until the point of vitrification is reached 1 200 1 300 degrees This is considered to be a relatively high temperature but it is neces sary to assure the vitrification of the clay and glaze Now the piece will not be affected by water Leave it to cool down in the kiln Hollow Guides This technology while less apt for our ends given that it is fairly weak is very common in the making of ornaments Liquid de fluctuated clay slip is used see figure A 7 Create the form The starting point is sets of molds of cast plaster In the form ing of the molds the contraction has to be taken into account The molds are filled with liquid clay and then emptied out until a layer of clay forming
181. ticipation Even with these weaknesses it is interesting to observe that an evaluative study carried out two years later indi cated that 67 of the pumps visited were functioning even though there was no maintenance system 26 of all the pumps were not working due only to problems with the rope a minor repair Users were generally content with the pump Tak ing these circumstances into account these results are very positive Chapter 1 A developing technology 23 Bit by bit the National Engineering University UNI changed its policy The UNI was sponsoring the project in collaboration with the San Jos Cooperative and it prioritized commercial and ac ademic aspects The cooperative lost its role as protagonist stopped producing and limited itself to selling its inventory In the same penod in 1988 DAR Region V decided to expen ment with the rope pump in one of its institutional rural water supply and sanitation programs The iron wheel was reinforced and embedded in a concrete slab to protect the well The bear Ings and the blocking system were improved After two years of limited implementation positive results were seen and the rope pump was adopted as standard in all DAR Region V projects A sales system was also established not only of rope pumps but also of construction materials for improvement of wells la irines floors etc ail in combination with technical assistance and sanitation education A credit fund was
182. tion approach for the rope pump Each initiative has its philosophy and pursues its objec tives Although we try to focus on the essential characteristics that all rope pumps have in common and reflect the different concepts designs and approachies references will inevitably be defined by the Nicaraguan expenence and conditions in gen eral and DAR Region V in particular Therefore we don t dis cuss only the known alternatives with their advantages and dis advantages we also try to present the logic that exists behind each option so that the reader can decide which solution is the most appropnate for the specific case or if there are conditions which iavor other alternatives not covered here To conclude it is important to emphasize that we in no way con sider the rope pump a finished product We are aware that development continues and we hope that this book in a short time will be outdated by other improvements in the pump and in implementation approachies Perhaps you reader can con tributeto this process We wish you enjoyable reading and request that you send us not only your comments on the book but also your experiences with the rope pump See addresses at the end of the book Bernard van Hemert Jan Haemhouts Osmundo Solis Orozco Orlando Amador Galiz The challenge of popular technology If you want to know what a wolf is capable of ask the sheep If you want to know what technology is capable of
183. to account all the known options TABLE OF CONTENTS Introduction ccc cceccececcnccecscscesceececes Part I The Challenge of Popular Technology The rope pump a developing technology 1 1 General description of the pump 1 2 History of pumping technology 1 3 The rope pump in Nicaragua 1 4 Implementation approaches Basic rope pump conepts A felt need by the beneficiaries Impacting health Self sufficiency Social control Village level operation and management Local manufacture Technology transfer TheoreticaHtechnical concepts Characteristics 3 1 Operation and management 3 2 Reliability 3 3 Discharge rates pumping heads efficiencies 3 4 Water quality protection 3 5 Costs Production 4 1 Production levels 4 2 Production organization MYUMMYMUNN Con OOP GN Perspectives 5 1 Implementation 5 2 Research and development 13 25 35 38 40 41 42 43 45 46 49 57 60 64 67 71 74 80 81 10 11 12 Part Il Construction Description of the pump 6 1 General description 6 2 The well siab 6 3 The wheel 6 4 Pistons rope and raising main 6 5 Guide and stabilizing rock 6 6 The discharge spouts Mechanical and hydraulic characteristics 7 1 Ergonomic factors 7 2 Choosing diameters for the pulley wheel and raising main 7 3 Hydraulic and mechanical efficiency Part Ill Installation operation and maintenance Installation in hand dug wells 8 1 Construction
184. to be the agents of technology transfer as not as important in this process as is commonly believed On the other hand it confirms the importance of social participation 14 First part The challenge of popular technology Chapter 1 A developing technology 15 Mean discharge rate during this hour 0 41 L s 1 400 i Ue Bee 1 200 ew O i fi Total daily output 7 944 L 1 000 F lt BIS Discharge rate Litres hour 6 7 B G 10 11 12 13 4 15 16 17 18 19 2 Hour of the day Figure 1 8 Hourly discharge rate en the El Pochote hand drilled well both in the definition of criteria in the technological development process and in the actual processes of innovation and transfer It also demonstrates the necessity of combining the process of transfer and generation at the community level with some sort of institutional support Preliminary studies and experimentation accelerate the development and transfer of technology Rope pump technology was introduced for the first time in Nica ragua in 1983 in the Santa Cruz community outside of Estel1 with the installation of a prototype in an 18 meter well The pump was made at the Cenier for the Investigation of Appropri ate Technology CITA INRA of the Agrarian ReformMinistry This version was based on previous experiences in Haiti which were adapted to what was estimated to be the area s economi cal and technical level There was no criteria developed about 1
185. tor would not be Photo 31 Pump on a stationary windr ill Note the simple construction of this mill The pulley at the far end of the rotor axle im mediately activates the pump s rope A 1 2 pump is connected but to the left can be seen a 1 4 pump for periods of higher winds Tipitapa feasible Pumping heads of more than 40 meters Should be possi ble although there are no exist ing prototypes functioning We do not reccomend the implementa tion of this pump model unless it is for experimental purposes or under the strict monitor ing of the manu facturer Chapter 15 Rope pumps with windmills Issues involved In zones with stable wind systems it could prove interesting to use wind energy to pump water for cattle irrigation or even for use as drinking water The philosophy of rope pumps driven by windmills is to use a small mill leaving open the possibility of working the pump by hand in case of mill or wind failure Description of the model As power is limited the rotor has a relatively small diameter 3 meters maximum Although it should always be taken into ac count that the wind is a very irregular and sometimes even dan gerous energy source the small rotor allows for a relatively sim ple but safe construction model Two different designs exist The most simple has a fixed head which doesn t turn with the wind See photo 32 Although its yield is small due to this limi tation the sim
186. trips Besides the greater weight makes the stabilizing stone unneccessary This guide has considerable advantages The only problem with implementation on a large scale is that it can be difficult to get access to the isolator Altemative 5 Regarding the wooden guide the same observa tions apply as those made for wooden pistons Don Pompilio comments on the useful life compared to the 112 Second part Construction guide with isolator brought a new guide with isolator Be fore we had put in a piece of wood with a hole and it was not working any more because it had had the same guide for three years It was too worn down It was not the same as this one with the isolator 6 6 The discharge spouts The discharge spouts serve to divert the pumped water from the raising main to the user s bucket As shown in the photographs In this book it consists of a container with a greater diameter than the rais ing main to permit the water to be diverted around the piston In our case it consists of pipe with a larger diameter than the raising main given the relation demonstrated in table 6 6 It includes a T joint a piece of horizontal tube with an elbow at the end this is not indis pensable and a piece of vertical tube to avoid the water from over flowing The well siab is secured through two iron jointings 1 4 To permit the dismantling of the pump the T joint is not glued to the rals ing main Construction Alternatives 7
187. ulley wheels The use of molds for welding the pulleys is one of the innovations that allow for quality and uniformity while maintaining high output Ignacio Lopez Workshop Managua In many develop ing countries the communication systems are faulty and an effi cient banking sys tem is not accessi ble to the majority of the small work shops _ Distribu tion of raw materi als or semi manufactured in puts is not fluid and supposed de livery dates are not honored These factors lead to the inevitable conclusion that the installation of a rope pump re quires excellent planning The easiest solu tion is to maintain a large stock of parts but this is expensive and requires inactive capital It also can induce poor planning in terms of ordering new sub products on time As one warehouse worker comments frequently there is still a lot in storage Chapter 4 Production 77 Another strategy used is to gather all the tools to make the ma jority of the parts within one business the value of the machin ery to produce the wheels guides pistons and rope adds up to approximately 5 000 which is relatively little The advantages of this strategy are Easy planning of production All of the machine operators know what a rope pump is and understand the importance of each piece of the pump However the disadvantages are considerable The distribution of raw materials and of the products is com
188. umberto Zapata Sanchez and Concepcion Mendoza Castro Social Promoters What Is your work related to the issues of potable water and en vironmental health Humberto I work in the DAR Rural Aqueduct Office in Boaco and my training to be a promoter took place in 1984 During my ear ly experience as a promoter worked with small aqueducts and com munal wells which were equipped with Demster 23F and Monitor pumps Our work is to see that the communities have access to pot able water and that those in the countryside enjoy better health Concepcion l was trained to be a promoter in November 1989 For me the job of the promoter is to provide more information to the community broaden their knowledge regarding the social needs that should be taken into account in the rural area in order to better the standard of living of the people who live in those communities Through experience what opinions have you and the communi ty members formed regarding the use of the various types of pumps Humberto am familiar with the Indian the Demster the Monitor and many more These pumps are very problematic in the rural are as Beginning with their installation the pumps require a specialized team that is familiar with that type of pump And you need a vehicle a number of tools and a lot of people to help you since the tubes and tools are heavy One person alone couldn t install a pump The parts are imported we don t make them
189. umps with PVC raising mains JADHPP90 02 Ellecom Holanda 1990 Burandt U Ergonomie fGr design und entwicklung Koln 1978 Appendix 219 Faulkner R D and Lambert R A The use of the rope washer pump In micro scale irrigation in Proc Instn Civ Engrs part 1 1990 88 February pp 81 90 Heuthorst Nicolaas Informe de los estudios sobre el rendi mlento hidraulico de la bomba de mecate Informe no publi cado DAR Region V Juigalpa Nicaragua 1991 IRC Handpumps Issues and concepis in rural water sup ply programmes Technical paper No 25 La Haya Holanda 1988 Lambert R A How to make a rope and washer pump IT publication Londres Inglaterra 1990 ISBN 1 85339 022 4 Mulvani P et al Tools for agriculture IT publication Lon dres Inglaterra ISBN 0 946688 36 2 Orozco Eduardo La bomba de mecate CITA INRA Mana gua 1984 Solis Orozco Osmundo e a Informe de evaluacion tecnica de las bombas de mecate Instaladas en Blueflelds Informe no publicado DAR Region V Juigalpa Nicaragua 1990 Teijen Reinder van Manufacture and engineering Rope pumps a review of ten years experience Dieren Holanda 1986 Watt S 21 Chain and washer pumps IT publications Lon dres Inglaterra 1976 Appendix Addresses in Nicaragua Name Description Contact Address Tel Fax Name Description Contact Address Tel CEPAD Department of Appropriate T
190. ure Perspectives 81 under the above mentioned conditions and as the conviction spreads so does the demand for the pump on the part of indi viduals as well as small and large institutional projects When questioned about the future of the rope pump Humberto a co ordinator of promoters answers this depends on the con sciousness regarding the problem that the pump is resolving in rural communities This depends on the level of consciousness of the donor agencies as weil as the institution that assumes any given project and their ability to recognize that here in this country what is needed is something that we can resolve with our own resources For implementation to be carried out on a greater scale the network of producers suppliers distributors and installers still needs to grow This is important not only to increase coverage but also to foment continuous development of the pump in tech nical aspects as well as different methodologies forimplementa tion user building sales institutional projects This support can be given through exchanges of experiences constructive or by competition conflictive Given that many enterprises and private cooperatives are interested in protecting their product and their market a combination of these two factors which en courage development would be the most probable 5 2 Research and development One central problem in researching the rope pump is that at the present time
191. use joints 4 Change the damaged part of the tube 5 Change tubing suppliers or use small er diameter pistons The same problem except that it happens every 10 to 30 turns of the pulley wheel depending on the depth The same causes described above but they affect only one piston Identify which piston has the problem some irregularity or bigger diameter and grind it Chapter 10 Troubleshooting 159 Problem 2 Symptoms the rope gets completely stuck it won t move for wards or backwards even a millimeter Alfonso a promoter in Palo de Hule describes the problem like this n some of the visits I ve made after the pump is working there have been some problems There was one where some garbage got into the tube and the rope was completely stuck But the user fixed it Possible causes 1 The rope was very loose and got tangled in the guide 2 Something is caught between the flare of the raising main and a piston for example an inner tube or a plastic bag Problem 3 Solutions 1 Take out the tubing untangle the rope and cut it so that the play is between 100 and 200 mm 2 Take out the tubing try to remove whatever is causing the obstacle which may be impossible in which case you will have to cut a piece of the tube As a pre ventative measure keep the slab sealed or make a filter around the guide and the tubes out of a piece of 4 or 6 slotted PVC tube S
192. ust be symetrically smooth A manual extruder to give its general shape cut A A of plane A 5 and after several days of drying the curves can be made with knives It is clear that the first method is quicker and only requires a simple wooden mold within the cinva ram machine In the 15 the cinva ram machine has its principal application in the production of cement blocks earth cement or adobe E Specifications of the glazed ceramic guides 199 shape both of the mold and the mouth of the extruder a con traction of 10 to 14 total during the whole process must be tak en into account Dry the guides carefully in a shaded windless place tor five or six days then sand them especially the curves of the orifice First Firing As the guides are pieces that are thicker than is normally found in ceramics 40 mm instead of 8 15 mm the drying and firing must be done very carefully in order to avoid cracks lf cracks are noted it means that the drying must be done in a slower fashion Just before firing it is preferibie to dry them several days in the sun turning them occasionally or better yet close to an oven at a temperature of 50 100 degrees to assist in the dryingprocess Load the kiln and heat it slowly 1 degree per minute with the door somewhat open to let moisture escape until reaching the point where chemical water escapes 380 400 degrees Maintain the kiln at
193. vel Operation and Management One concept which has received growing attention by drinking water and Sanitation project leaders is Village Level Operation and Management VLOM Although there are many different manifestations of this basic concept all share various essen tials the community members themselves are able to decide on all the aspects of pump operation and maintenance they orga nize and carry out all activities Normally there is a drinking wa ter committee and various people trained to make repairs The rope pump has all the characteristics of a good VLOM pump But it isn t only the technical characteristics of a pump that make it appropriate for VLOM The whole working method for developing the water system should work toward a VLOM situation There should be support for the formation of a water supply committee training of various villagers in pump mainte nance access to necessary tools spare parts and supplies etc In short once the system is set up the community alone should be able to keep it functioning In Nicaragua the majority of rope pumps have no institutional maintenance system One exception is the rope pumps in stalled by DAR Region V where there is an institutional opera tion and maintenance system that primarily limits itself to water quality control Repair work is minimal In the majority of cases there is training of users around all aspects of pump mainte nance both organizational and technic
194. ves Although we don t go into detail about such al ternatives here we do refer to them in the second part The installation of the pump in the community well offers an ex cellent opportunity to train the users in the installation operation and maintenance of the pump Since all the activities are carried out in the same community it is feasible for women to partici pate As Cony a promoter points out Just about everyone has the right to participate and everyone can participate including the women The kids can participate in the installation and re pair It s not hard at all that s how see it As with any construction project in the countryside good plan ning is essential Having all the materials and resources in place the pump can be installed in less than two half days one to pour the concrete slab and a few hours the following week to complete the installation Before beginning the collection of materials the diameters of the tube and the pulley wheel must be chosen according to the depth of the well In section 7 2 we describe these procedures Chapter 8 Installation In hand dug wells 133 8 1 Construction of the slab Here we list the necessary conditions and tools for the construc tion of the slab The quantities listed here for the matenales are for a slab with a 1 2 meters diameter for other sizes the quaniti ties need to be adapted accordingly We finish with a summary of the step by step procedures
195. ves and future development of the rope pump 80 First part The challenge of popular technology Chapter 5 Future Perspectives In the last chapter in this section we briefly discuss the possible perspective for the rope pump regarding the implementation of the present pump 5 1 and for research and development 5 2 We also include the possiblities for the special models of the rope pump described in the fourth part the pump on a drilled well post mounted fcr high discharge with a motor and with a windmill And finally we mention some research aspects with respect to construction making reference to the respective sec tions in the second part 5 1 Implementation Given the characteristics described previously we can conclude that the rope pump can be implemented without any problems under the following conditions The well can be drilled or dug by hand and up to 25 meters deep It can be a public or private well but there must be some so cial control The daily pumping is 4 m3 or less The pump can be a model for an drilled or dug well with a high discharge or post mounted With close follow up the implementation of the pump under the following conditions can also be considered A well up to 40 meters deep and or with a demand of up to 8 m3 daily A pump with a motor In Nicaragua every day the conviction becomes more wide spread that the rope pump is truly the most appropriate pump Chapter 5 Fut
196. wells with storage tanks it is usual ly the man or oldest son who fills the storage tank various times during the day There is thus not a clearly defined impact group in terms of the pump s use Usually men take charge of mainte 36 First part The challenge of popular technology Photo 6 Women are the principal users of the pump Pregnant woman staying at the Birthing Center drawing the daily wash water Nueva Guinea nance although there are many cases in which women repair pumps At any rate women should always be explicitly in volved in all d cisions activi tles and trainings around any drinking water project We will thus use the femi nine form when referring to users beneficiaries etc although we are clearly not exclud ing men If we ask any peasant wom an for a list of cri teria to choose a source for drinking water she will re spond with a list something like this 1 the distance and the topography of the trajectory 2 the cost per bucket of water 3 the flavor color and smell of the water 4 the social climate around the well Chapter 2 Basic rope pump concepts 37 5 the ease with which water is drawn 7 and oniy maybe at the end would she mention the bacterial quality of the water We may disagree with these priorities but we have to accept them as the basis for our activities It is true that through health education it could be possible to
197. wire insert the rope with the pistons into the raising main tubes starting from below Remember to pay special attention to the direction of the pistons The rope should pass through the big opening of the guide It s important to demonstrate these steps very clearly to the users owners given that replacement of the rope is the most common corrective maintenance procedure and errors often occur for example the rope doesn t pass through the guide or the pis tons face downward Don Ramon had this experience l installed it wrong put the tube in all the way put the rope in and didn t put it through the porcelain piece which should be fastened securely with its turns so that the rope and the pistons don t hit forgot about the porcelain piece wanted to turn it over but it wouldn t When I saw Alfonso a very responsable Chapter 8 installation in hand dug wells 145 Guide eee for drilled well PY Bel conan as 146 Third part installation operation and management 147 Chapter 8 Installation in hand dug wells 148 Third part Installation operation and management it F a Be i Photo 23 Well placed bearings The wide wing of the upper bearing half rests against the support and prevents the bearing halves from rotating Narrow wings prevent the bearing halves from becoming dislodged Papayal kid he came to put the tube together When we turned it over the rope entered the
198. ymptoms The rope can be moved with some effort a few me ters forwards or backwards but then gets stuck The rope is very worn out Possible causes 1 The guide has come unstuck from the raising main the rope has dragged along a crack in the ralsing main 2 A very wom out guide has been used and it has a deep crack Solutions 1 Cut the affected part of the raising main and change it Make another flare and carefully secure the guide to the new tube 2 Change the guide 160 Third part Installation operation and management Photo 26 Rope in the pulley wheel When the tire walls aren t very strong or when the pull on the rope is very great the rope can get caught within the center of the pul ley wheel See problem 5 San Juan Problem 4 Symptoms The rope gets stuck between the nms of the wheel Possible causes Solutions 1 The pulley wheel sup 1 Push the pulley wheel supports togeth ports aren t holding the er or insert a wedge between the sup two rims of the pulley ports and the rims wheel together 2 Use more spokes or thicker tires for 2 The rims of the pulley the rims wheel are weak and spread apart A general solution is to cover the V of the pulley wheel with a bed of inner tube This will not work if there is too much force the rope will slip Chapter 10 Troubleshooting Problem 5 161 The rope slips on the pulley wheel Possible cau
199. ze various training workshops for promoters from the central Rural Aqueduct Office DAR of INAA as well as community representatives Despite CITA s efforts to bring INAA into the project and the presence of several high level staff members who were con vinced of its importance no significant advance was made During the first years professional and institutional representa tives in contrast to the community acceptance regarded the rope pump s technology with little interest This resulted in an incongruency between the appearance of acceptance and an declared rejection Chapter 1 A developing technology 19 TE Given the suc cess of the rope pump at a semi nar on low cost water supply and Sanitation tech nologies orga nized in 1987 by INAA PAHO UNICEF a plan was developed to produce a senes of pumps consid ering the possibil ity of implement ing the techno logy in popular neighborhoods in Managua shortly after wards prepara tions for pump production began near the capital with sales pro duction coordinat ed with various popular organiza tions and the Del egate of the Pres ident Prionty was given to the project s social 4 TS i Photo 3 One of the pioneers Don Pompilio with his wife and grandchild The photo also shows one of the first pumps installed in Nicaragua Against the left leg a wooden guide and another guide with an por celain insulator Against the right l

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