[[Image:drilling icon.png{{Language-box|right]][[Image:english_link= Percussion drilling in action.jpg|thumbfrench_link= Coming soon | spanish_link= Coming soon | hindi_link= Coming soon | malayalam_link= Coming soon | tamil_link= Coming soon | korean_link= Coming soon |rightchinese_link=冲击钻井 |250pxindonesian_link= Coming soon | Percussion drilling in action]]japanese_link= Coming soon }}[[Image:Weighted drill bitdrilling icon.jpg|thumbpng|right|250px| Weighted drill bit80px]]__NOTOC__
Percussion drilling is a manual drilling technique in which a heavy cutting or hammering bit attached to a rope or cable is lowered in the open hole or inside a temporary casing. The technique is often also referred to as 'Cable tool'. Usually a tripod is used to support the tools. By moving the rope or cable up and down, the cutting or hammering bit loosens the soil or consolidated rock in the borehole, which is then extracted later by using a bailer. Just as with [[hand auger - general|hand augering]], a temporary casing of steel or plastic may be used to prevent the hole from collapsing. When the permanent well screen and casing are installed, this temporary casing has to be removed.
===Suitable conditions ===[[Image:Percussion drilling in action.jpg|thumb|right|200px| Percussion drilling in action]][[Image:Weighted drill bit.jpg|thumb|right|200px| Weighted drill bit]]
Percussion drilling is suitable for unconsolidated and consolidated formations: Sand, silt, stiff clays, sandstone, laterite and gravel layers.
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! width="50%" style="background:#efefef;" | Advantages
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| valign="top" | - Unlike any other drilling method, percussion can remove boulders and break harder formations, effectively and quickly through most types of earth. <br>
===Construction, operations and maintenance===[[Image:Diagram of percussion drilling.jpg|thumb|right|250px200px| Diagram of percussion drilling]]
Equipment is commercially produced in western countries. Local production is possible. Percussion drilling is hard work. Use of a small engine may be appropriate.
====Suppliers====
* [https://en.eijkelkamp.com/ Eijkelkamp Agrisearch Equipment ] - Drilling equipment and manuals on hand auger and percussion gouges - http://www.eijkelkamp.nl
* [http://www.vrm.nl/ Van Reekum Materials ] - Drilling equipment, hand auger and percussion drilling - http://www.reekum.nl
===Costs===
For cost comparisons between hand drilling and percussion drilling: [http://www.wellspringafrica.org/WebManual/costcomp.htm Wellspring Africa's Hand Powered Percussion Drill] illustrates costs for materials, tools, and labour.
===Field experiences===
Percussion drilling is mainly used in Niger, Nigeria, Chad, Liberia, Ghana, Central America and western countries.
==Reference manuals=Manuals, videos, and links===* Robert Vuik, Don de Koning and Arjen van der Wal. [http://www.surechempractica.org/wp-content/uploads/services/publications/drilling%20manuals/EN/Percussion%20manual%20drilling%20PRACTICA%20EN.pdf Percussion: Manual Drilling Series. Technical Training Handbook on Affordable Manual Well Drilling]. Practica Foundation, June 2010. French version: [http://www.compractica.myorg/wp-content/uploads/services/downloadpublications/eijkelkampdrilling%20manuals/P1FR/P1-21ePercussion%20manual%20drilling%20PRACTICA%20FR.pdf FORAGE À LA PERCUSSION: Série forage manuel]. * [http://www.surechem.com.my/products.php?cat=2010 Percussion Drilling]. Different kinds of drills and connectors.
* [http://www.wellspringafrica.org/manual.asp Drilling Wells by Hand], Cliff Missen, Wellspring Africa, draft 4 - Manual on Percussion drilling, well construction, manufacturing tools. [http://www.wellspringafrica.org/drildesc.htm Website of WellspringAfrica]
* A Water Handbook, Technical Guidelines Series, UNICEF, 1999 - Programming and implementation. [http://www.unicef.org/wash/files/Wat_e.pdf Download].
* Technology notes, section 7; Tube wells and boreholes, WaterAid - An overview of human-powered drilling technologies. [http://www.wateraid.org/documents~/plugin_documentsmedia/technology_notes_2008Publications/technology-notes-2011.pdf Download]. Website of [http://www.wateraid.org/uk Wateraid.org].
* Water for the World, Technical note series rws 2, USAID 1982 - Technical notes on methods of developing of groundwater, manual drilling techniques. [http://www.lifewater.org/resources/ground_water.html Website Livewater Lifewater International]. Under 'Cable Tool Wells'.
* Multi-service procedures for well-drilling operations, field manual chapter 9, US Military Chapter 9, alternative well construction, manual drilling techniques - [http://www.paulsawyersnavybmr.com/pdfsstudy%20material/14080a/FM_5_48414080A_ch9.pdf Download].
*[[Solution_of_the_week_13|Akvo solution of the week 13]]
=== Acknowledgements===
* The basis for the material on this page was obtained from a desk study shortly to be published on the website of the [http://www.practicafoundation.nl/ Practica Foundation], and from the [http://www.rural-water-supply.net/ Rural Water Supply Network], and specifically its [http://www.rural-water-supply.net/en/implementation/manual-drilling manual drilling section].
* [http://www.lboro.ac.uk/well/resources/technical-briefs/43-simple-drilling-methods.pdf 43. Simple drilling methods.] WEDC.