Underwater pipe-laying vessels and methods

摘要

A pipe-laying vessel includes a vessel that is propelled during pipe-laying; a tower on the vessel; a device for raising a length of pipe from a deck of the vessel to a position aligned with the tower; a device for joining such a length of pipe to a pipeline being laid; and tensioners arranged to grip such a pipeline and to lower it into the water while maintaining a desired tension in the pipeline as the pipeline passes through the tensioners; and one or more clamps arranged to grip the pipeline below the tensioners.