UNDERWATER PIPE-LAYING VESSELS AND METHODS

摘要

A pipe-laying vessel comprises: means (2) for propelling the vessel during pipe-laying; means for assembling sections of pipe generally horizontally on the vessel to form longer lengths; a tower (14) at the bow of the vessel, wi th respect to an intended direction of movement, pivotally mounted so that it c an be angled forwards towards the top; means (29) for raising a length of pipe fromthe deck to a position aligned with the tower; means (21, 23) for joinin g such a length of pipe to a pipeline being laid; tensioners (20) arranged to grip such a pipeline and to lower it into the water while maintaining a desired tension in the pipeline; one or more clamps (18) arranged to grip th e pipeline below the tensioners; and a lower ramp (17) provided with rollers a nd arranged to guide the pipeline as it leaves the vessel.