The invention relates to a
submarine pipeline laying
machine and hydraulic jetting combined rotating ditcher for 500-meter deep
hardpan, is applied to a
submarine hardpan seabed of 500 meters and within 500 meters, and belongs to the technical field of
marine engineering equipment. The ditcher comprises main parts such as an external bracket, an outer rotating cylinder, cutter teeth, an upper suspension cylinder, a lower support pillar, a
plough share, nozzles, a high-pressure
water pipe, an inner cylinder, baffle plates, a sealing rubber waterproof pad, a motor, an output transmission shaft, a shaft
coupling, an upper-plane ordinary
gear train, a lower-plane ordinary
gear train, a top cover, a bottom cover and bearings, wherein the top cover, the bottom cover, the outer rotating cylinder and the cutter teeth are driven by the motor through the upper and lower-plane ordinary gear trains to rotate to realize a
seabed groundbreaking function; the
hardpan can be crushed by high-pressure water jetted by the high-pressure
water pipe and the nozzles, so that the
cutting resistance of the cutter teeth is reduced; liquefied soil is sucked out by a
slurry pump suction
pipe to realize a
submarine ditching function. The ditcher has the advantages of being large and deep in ditching, high in working efficiency and environmental adaptability, remarkable in social and
economic benefits, and the like.