Changes

[[Image:Icon_sludge.png|right|80px]]

[[Image:Rota sludge in action.jpg|thumb|right|200px|Rota sludge in action]]

[[Image:Deep drilling with the rota sludge.jpg|thumb|right|200px|Deep drilling with the rota sludge]]

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.