Heave compensation apparatus for a marine mining vessel

摘要

A ship in which a string of heavy pipe is raised or lowered vertically beneath the ship at a substantially constant velocity in spite of heaving movement of the ship. The equipment for raising and lowering the pipe string is supported by the vessel through a heave compensation mechanism that permits vertical movement of the ship relative to the pipe raising and lowering mechanism. The heave compensation mechanism is a passive damped pneumatic-hydraulic spring system for isolating the vertical movement of the ship from the pipe raising and lowering equipment. The spring system operates over a very wide range of load imposed by the raising, lowering and supporting of a very long heavy pipe string.