Clamp assembly for pipe-laying vessel and method of laying a pipeline

A pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, the vessel comprising:

• a welding station for joining a new pipestring to an end of the pipeline held by the tower,
• a plurality of clamps on the tower for holding a new pipestring with a lower end adjacent to the end of the pipeline held by the tower and with the pipestring extending upwardly from its lower end alongside the tower,
• wherein the plurality of clamps includes a pipestring clamp for clamping around an upper end of the pipestring and the pipestring clamp is part of a clamp assembly that also comprises an internal line-up clamp arrangement, the internal line-up clamp arrangement and the pipestring clamp being adjustably mounted for adjustment, as a unit, of their orientation relative to the tower.

A pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, the vessel comprising:

• a welding station for joining a new pipestring to an end of the pipeline held by the tower,
• a plurality of clamps on the tower for holding a new pipestring with a lower end adjacent to the end of the pipeline held by the tower and with the pipestring extending upwardly from its lower end alongside the tower,
• wherein the plurality of clamps includes a pipestring clamp in the region of the top of the tower, the pipestring clamp is arranged to bear at least the major part of the weight of the pipestring and the pipestring clamp is also able to rotate the pipestring about its longitudinal axis.