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2.1.6 Rope-washer Pump
The rope-washer pump consists of a rope with knots or rubber
washers, whose diameters are slightly less than the diameter of the pipe,
placed at intervals along it (Figure 32). This assembly is drawn up inside
a rising pipe, and is capable of drawing relatively large volumes of water
to the height of the pump. During operation, the pipe is inserted into
water and the rope drawn upwards through the pipe by means of a winding
drum with a crank. Water is also drawn up and discharged at the top. The
rope and washers pass round the winding wheel and return to the bottom of
the pipe thus completing the circuit. This design can be modified to avoid
slippage of the rope on the pulley by using old tyre casings to make the
pulley wheel. To prevent the washers getting caught, and to support the
bottom of the pipe above the bottom of the well or river bed, a suitable
pipe stand and rope guide is necessary. Friction should be kept low by
allowing leakage between the washers and the pipe stem.
Figure 32. The rope and washer pump (Lambert, 1990).
Extent of Use
The rope-washer pump is receiving moderate use in Kenya, Zimbabwe and
Operation and Maintenance
Rope-washer pumps rely are manufactured locally, and, therefore, are
amenable to local repair and maintenance using simple, locally-available
Level of Involvement
The components of this technology are community-manufactured and
operated. Government and NGOs are often involved in the promotion of this
technology and development of refinements.
Rope-washer pumps cost between $30 to $50 to construct. The construction
cost increases in proportion with the lift required.
Effectiveness of the Technology
This technology is appropriate for all domestic uses and
micro-irrigation or garden irrigation uses. This pump can pump high
volumes with a low lift.
The technology is suitable for abstraction from shallow wells of up to
10 m depth or from rivers and streams. It is easily adaptable to changing
volumes by adapting the diameter of the pipe and washers.
The introduction of a simple device such as the rope washer pump, lends
itself to micro-scale gardening and the accompanying positive
environmental management practices.
The pump has no valves and does not require complicated bearings. It is
easy to manufacture, with local resources, and is ideal for flood
irrigation of small gardens.
The pump has limited lift and poor pumping efficiency, as water is
allowed to leak through the valves.
There are no known cultural inhibitions.
Further Development of the Technology
The rope-washer pump technology needs to be further disseminated to gain
additional field experience of its operation. The efficiency of the pump
needs to be improved.
Chleq, J.L. and H. Dupriez 1988. Vanishing Land and Water. Soil and
Water Conservation in Dryland. Macmillan, 117 p.
Lambert, R.A. 1990. How to Make a Rope Washer Pump. Intermediate
Technology Publications, London.