Abstract: An apparatus for rotating a floating vessel such as a ship, around a cylindrical turret structure moored to the sea bottom. The vessel has a circumturret structure passing through the hull of the vessel and surrounding the turret structure. The apparatus comprises a hook roller assembly, a load roller assembly, a radial roller assembly, and a drive mechanism. The hook roller assembly prevents the turret structure from moving upward from the wave and current forces exerted on the floating vessel. The load roller assembly rotatably supports the turret structure on the circumturret structure. The plurality of radial roller assemblies mounted to the circumturret radially support the turret. The drive mechanism is used to rotate the vessel around the turret.

Abstract: A drum winch is replaced with a traction winch module. The traction winch module is mounted on and supported by the existing mooring winch frame of the drum winch. The traction winch module includes a traction frame, a front traction drum, and a rear traction drum. A portion of the drive system from the drum winch may be retained and used to drive the traction winch module. In one embodiment, the traction winch module is designed to mount between pillow blocks from the existing mooring winch frame. In addition, the power train and load-sensing systems from the existing drum winch may be used with the converted traction winch to drive the drive shaft and to provide the converted traction winch with tension information, respectively.

Abstract: A passive riser tensioner apparatus for tensioning riser pipes on floating platforms and tension leg platforms utilizes one or more elongate elastic tensioning elements connected at top and bottom ends to the upper end of a riser pipe that are capable of being axially stretched. Each tensioning element has a threaded length adjustment rod and tension preload nut at its top end which adjusts the axial length to produce a predetermined preload tension force in the tensioning element between its connection to the riser pipe. A riser support collar slidably received on the length adjustment rod and riser pipe upper end is configured to be supported on the deck of the platform and allow axial movement of the riser pipe. A tension locking nut on the length adjustment rod releasably engages the length adjustment rod with the riser support collar when it is supported on the deck.