[[Image:Rota_sludge_well_drilling_icon.png|right]]
The Rota-sludge method is an adaptation of the Indian hand sludge method. The hardened drill bit is turned 90 degrees during drilling thus chiselling the bottom of the hole. This technology can be used to drill 2-5 inch wells in layers with sand, clay, gravel, tuff stone or weathered rock.
[[Image:Rota_sludge_well_drilling.PNG|thumb|right|150px|Drilling a 20 m deep well in Chinandega, Nicaragua, with the Rota-sludge method ]]
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! width="50%" style="background:#efefef;" | Advantages
! style="background:#ffdead;" | Disadvantages
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| valign="top" | Drill in hard soil.<br>
<br>
| valign="top" | <br>
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== Capacity ==
2-5 inch wells to 20 meter.
== Costs of wells ==
US$ 30 India.
US$ 80-400 Nicaragua.
== Applying conditions ==
<ul>
<li><b>Cost of introduction:</b> Variable US$ 5,000-20,000 per project, including hand-on training, drill set and drilling of test wells.</li>
</ul>
== Rope pump building manual ==
PRACTICA foundation and the Technical Training Programme of the ETC Foundation (TTP/ETC) have put together a really [http://www.greenocean.org/akvo/PRACTICA_180306_Rope_pump_manual_Ethiopia_March_2006_complete.pdf excellent manual on how to build rope pumps] (PDF, 2.5 Mbyte). It is an 86 page long document with detailed instructions.
== External links ==
* Evaluations [http://www.irc.nl www.irc.nl ]
* Africa [http://www.pumpaid.org www.pumpaid.org ]
* General info [http://www.ropepump.com www.ropepump.com]
* How to build [http://www.ropepumps.org www.ropepumps.org]