Submarine pipe laying gantry - with semi automatic chain attitude and tension control using electrically controlled hydraulic jacks

摘要

A framework (1) supports the chains and drive system on the boat. The lower chain drive is adjustable in height and angle by transverse forward and aft beams (35) which are driven up or down by hydraulic jacks (30), mounted inside vertical support tubes (71). A similar system in support tubes (72) drives the upper chains, the four jacks in this case having a long travel so that different pipe sizes can be accommodated. The forward pair and aft pair of jacks in the lower system are each driven by one pump, whereas each jack in the upper system has its own pump and a pressure sensor. In use, the attitude and height of the pipe are set by the lower system jacks, the pipe is positioned and the upper system jacks actuated.