Description: This technique is a variation of hand percussion drilling. A 60cm long cutting tool is fitted to the base of a drill pipe. A 70kg steel weight (or hammer) is lowered into the drill pipe. This hammer is raised and dropped onto the cutting tool, forcing it to penetrate the formation, before being lifted out carrying the cuttings.

Capability: The stone hammer drilling method can penetrate reasonably hard formation, but progress is slow.

Locations: Nicaragua and India.

Equipment Availability: No off the shelf technology is available, but the rig can be assembled in a reasonable local workshop. Drawings and assembly guidelines are available in the sources set out in the reference list.

Documentation:

Van Herwijnen, A. 2005a.  Rota Sludge and Stone Hammer Drilling – Part 1 Drilling Manual, PRACTICA Foundation & ETC Energy.  Maerten Trompstraat 31, 2628 RC Delft, the Netherlands

Van Herwijnen, A. 2005b.  Rota Sludge and Stone Hammer Drilling – Part 2 Production Manual, PRACTICA Foundation & ETC Energy. Practica Foundation Maerten Trompstraat 31, 2628 RC Delft, the Netherlands