Underwater excavation apparatus

摘要

An underwater excavation apparatus comprising a tube (10) in which a propeller (18) is mounted for rotation, with the tips of the propeller blades formed with jets (30) supplied from a high pressure water supply through passages in the propeller blades, impinging on vanes (31) mounted on the tube wall around the propeller to cause the propeller to rotate and thereby draw water through the tube from an inlet at one end to an outlet at the other end to act on the sea bed. The apparatus is particularly useful for excavating trenches on the sea bed and exposing previously covered installations. Variations on the form of the apparatus are described and illustrated.