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[[Image:Icon_sludge.png|right]]

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The Rota Sludge is a manual drilling technique based on the [[Sludging - Asian sludge |Asian sludge]] technique, and adapted for harder soil types. To drill through the harder layers, a hardened drill bit and weight have been added. Just after the downward movement of the drill pipes the drill bit is rotated a quarter turn, thus chiselling the bottom of the hole. Water is circulated to bring the cuttings to the surface.