This document analyzes the scale and technology required for sustainable manufacturing and supply of rope pump pistons in sub-Saharan Africa. It quantifies rope pumps installed and failure rates, assesses manufacturing volumes and costs to reach break-even points, and minimum pump densities for sustainable supply chains. The analysis finds pump density is critical to viability of spare parts supply. Existing densities often do not meet system density breakpoints, so prices may need to increase or support mechanisms provided. Manufacturing at a district level where criteria for viability can be met may be most suitable.

1. An Analysis of Scale and Technology in Rope Pump Piston Manufacture and Supply in Sub-Saharan Africa Donald J. MacAllister, Cranfield University, UK Dr. Brian S. McIntosh, International WaterCentre, Australia Erik Harvey, WaterAid UK

2. Rope pump technology Scale and Technology in Rope Pump Piston Supply

4. Density of demand (scale)

5. Private sector parts and services (skill)

6. Greater centralisation(support)

7. More use of locally available materials

8. Spare part supply chains the weak link

9. VLOM can be a barrier to sustainability

10. Low density areas may require subsidyHarvey, P.A., & Reed, R. 2006 Sustainable supply chains for rural water supplies in Africa. Proceedings of the Institute of Civil Engineers, Eng. Sus.159(ES1), pg.3139 Scale and Technology in Rope Pump Piston Supply

11. Study objectives Quantify the number of rope-pumps installed, and characterise rope-pump and piston failure Assess manufacturing quantity (volume) required for, and costs incurred at break-even Assess the minimum pump densities required to achieve break-even To make recommendations regarding the creation of sustainable supply chains with existing pump densities Scale and Technology in Rope Pump Piston Supply

13. the output level where total cost = total revenue

14. but … cost per unit output varies with the volume of output

15. Requires knowledge of production function:

16. Maximum level of output achievable across a given range of labour and capital inputs

17. Estimated for different piston manufacture technologies from interview dataScale and Technology in Rope Pump Piston Supply

18. Break-even analysis method Scale and Technology in Rope Pump Piston Supply

20. If not, what is the Optimum Price per Spare Part? Scale and Technology in Rope Pump Piston Supply

21. Results Scale and Technology in Rope Pump Piston Supply

22. Supply implications 1 – pistons or pumps? b) 15 pumps within 40km a) 682 pumps within 40km Illustration of the SDB in rope-pump supply for Ghana. For sale of single pistons, For sale of multiple pistons with rope. Note pump locations do not indicate actual pump locations Scale and Technology in Rope Pump Piston Supply

24. Spare parts not viable to retailers

25. In most cases existing pump density will < SDB. Ways to overcome this include:

26. Increasing unit price e.g. expanding into self-supply and irrigation markets

27. Promoting support mechanisms such as after sales service

28. This can increase functional sustainability and diversify manufacturer / retailer business making it more viable

29. Manufacture at a level where these criteria are possible, e.g. DistrictScale and Technology in Rope Pump Piston Supply

30. Questions, thoughts? Dr. Brian S. McIntosh b.mcintosh@watercentre.org Scale and Technology in Rope Pump Piston Supply