Underwater rock loosening system - thrusts tools in from above to disturb structure in uppermost layer of bed

摘要

The system loosens rocks from a sea or river bed, using one or more chisels inserted in the latter and hauled along a path parallel to it. The structure of the uppermost layer of the bed is disturbed by thrusting tools into it from above at different points. The tools (23) can be mounted round the periphery of a roller (24) travelling over the bed, and can be in the form of bars, sharp-pointed pins or inclined cones. They may be castings welded to the roller. the design reduces the wear rate on the chisel, and aids the breakup of the rocks so that they can be handled by a suction dredger.