Abstract: The system for digging subterranean galeries comprises a cutting tool articulated on a frame and mounted so as to be movable along the height of the mine face. This frame is provided with ground support means and with propulsion means for following the progress of the cutting, the articulation point of the cutting tool being situated in the upper half of the system in operating position. The articulation point of the cutting tool may be situated on a member movable with respect to the frame and movable in a direction substantially parallel to the direction of advance. The shaft bearing the cutting tool may be mounted on two bearings, one of which is movable vertically to give the tool an oblique path in a pre-determined direction.

Abstract: Underwater pipelines connected to at least one point on a coastline are constructed by means of a pipelaying vessel associated with an independent underwater vehicle mounted on caterpillar-tracks and capable of traveling along the sea bed. From within the vehicle, pipe sections can be assembled and rejected as the vehicle moves forward. The pipe sections pass through a wall of the vehicle and into the sea, through a port which is provided with a plurality of inflatable annular sealing rings that selectively sealingly bear against the exterior of the pipeline. One of these sealing rings is associated with an annular piston, and a jack acts between this piston and the vehicle to provide the propulsive force for ejecting the pipe sections from the vehicle. Potential applications include mining operations, off-shore installations and intercontinental tunnels.

Abstract: The method consists in boring a shaft in the sea floor to form a drilling station of sufficient size to accommodate personnel and equipment, in lining the shaft walls with a casing which is cemented against the walls and surmounted by a water-tight self-contained subsea chamber, in extracting sea water from the shaft, in maintaining atmospheric pressure within the shaft and the subsea chamber, in lowering personnel and drilling equipment into the shaft and in carrying out drilling operations from the bottom of the shaft.