Multipurpose Deepwater Vessel

A multipurpose deepwater vessel comprising:

• a floating structure, in turn comprising a bow;
• a stern;
• a weather deck;
• a first board and a second board;
• and a centreline;
• a J-lay tower hinged to the floating structure along the second board, and movable, about a first axis parallel to the weather deck, into a number of work positions;
• a heavy-duty crane connected at the bow to the floating structure to rotate about a second axis perpendicular to the weather deck, and having a boom defining an operating range;
• said J-lay tower, in any one of the work positions, being located within said operating range;
• and
• a preassembly line for joining pipes into pipe assemblies, each comprising at least two pipes;
• wherein said preassembly line is located below the weather deck and connected operationally to the J-lay tower.