[[Image:Rota_sludge_well_drilling_icon.png|right]]
For wells down to 35 m, rope pumps are often five times cheaper and more sustainable than piston pumps. Evaluations show that rope pumps on communal wells are being maintained by The Rota-sludge method is an adaptation of the users, if introduced properlyIndian hand sludge method. The hardened drill bit is turned 90% of rope pumps remain operational, even after many years. Because degrees during drilling thus chiselling the bottom of its low cost, the pump is also popular for domestic usehole. A survey among This technology can be used to drill 2-5,025 rural families inch wells in Nicaragua indicates that a rope pump increases income, even if used for domestic purposes only. Families layers with a pump earn US$ 220 per year more than families without a pump. In Nicaragua the pumps are now being produced commercially by 20 workshops. Different models of Rope pumps were introduced in Africa. This introduction has not always been successful: in some projects over 80% of the pumps do NOT work! Howeversand, with the "right" models and the "right" user trainingclay, upto 90% remain in operation in Africagravel, as the Victory model in Ghana and the Elephant model in Zimbabwe have provedtuff stone or weathered rock.
[[Image:Rota_sludge_well_drilling.PNG|thumb|right|150px|[[Rope pump | Rope pump ]], (Victory model) on Drilling a hand-dug of 20 meters m deep wellin Chinandega, Nicaragua, made in a local workshop in northern Ghana with the Rota-sludge method. ]]
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