Implementation • Handpump Technology

Rota Sludge

Description: The rota sludge technique is similar to hand sludging and the Pounder rig. It involves raising and lowering a steel pipe, which is weighted at the bottom and fixed with a drill bit on the base to drill the hole. A simple wooden frame and lever are used to enable the reciprocating action. Water mixed with cow dung is used as drilling mud – ie to carry the cuttings to the surface and prevent collapse of the drilled hole. A hand, placed at the top of the pipe acts as a valve, lifting up and releasing the cuttings on the down stroke and covering the pipe on the up stroke. A pit (Figure - above centre) enables the drill cuttings to settle out and thus the mud to be recycled. A handle is clamped to the drill pipe. This allows rotation of the drill pipe, which assists to scrape and break the formation.

The stone-hammer technique is used in conjunction with the rota sludge technique to penetrate hard formation.

Capability: Rota sludge drilling is capable of penetrating soft, sandy formations. Gravel and small stones within such formation can be lifted. The technique can be used to drill through, more cohesive sandy formations and most clay. When very stiff clay, layers of hard rock, or boulders are encountered, these are broken using the stone-hammer attachment. However, due to the limits of human energy, progress through such formations can be slow.

Locations: Nicaragua, Tanzania, Madagascar, Ghana, Senegal, Mauritania and Niger.

Equipment Availability: No off the shelf technology is available, but the rig can be assembled in a reasonable local workshop.

Documentation: