A pipe-laying vessel (1) is provided, including a tower (2) extending upwardly from the vessel, a pipe loading arm (9) for raising a length of pipe from the deck to a position aligned with the tower, a travelling clamp assembly (30) mounted for movement along the tower. The pipe-laying vessel may include a fixed clamp assembly (60) located in the region of a lower portion of the tower, wherein the travelling clamp assembly and/or the fixed clamp assembly includes both a friction clamp (34, 63) and a collar clamp (62), each of the friction clamp and the collar clamp being movable between an operative position, in which it is adjustable between a clamping and a released position, and an inoperative position. Alternatively or additionally the travelling clamp assembly (30) includes both a line-up clamp (33) and a pipeline tension bearing clamp (34). Alternatively or additionally there may be provided three or more line-up clamps (33, 35, 36) spaced along the tower for receiving the length of pipe from the loading arm.