Abstract: A single point mooring system e.g. for an offshore oil or gas production system, consists of a rotary turret 6 provided in a floating structure 1 e.g. a tanker to which the turret is retrofitted. The turret 6 comprises a skirt portion 11 on the underside of the tanker and an upwardly extending cylindrical chimney portion 12. The turret is connected to the seabed by mooring lines 3 and risers 6 supply oil to the tanker for temporary storage. The mooring lines 3 comprise segmented chains that are hauled by winches 20 and secured by stoppers 18, 19 in the skirt 11. The turret is rotatably suspended from the upper end of the chimney portion 12 by an upper main bearing comprising rotary rings 40, 41, which is interchangeable while the mooring system is in service. Annularly disposed lower bearings 26 are arranged to resist radial loads on the chimney portion but to be compliant to axial turret loads, to accommodate forces and moments applied to the turret and the tanker by wave action.

Abstract: A compensator for providing resilience in a connection between relatively moveable objects comprises a piston (3) working in a cylinder (2) which is surrounded by a larger coaxial cylinder (1) joined thereto by annular wall members (1a) thus defining about the cylinder (2) a pair of annular reservoirs (8,9). The piston (3) divides the cylinder (2) into a pair of chambers (6,7), chamber (6) being connected by conduit (12) to reservoir (9) and chamber (7) being connected by conduit (10) to reservoir (8). Each reservoir contains a mixture of liquid and gas while the chambers contain liquid. Elongation of the connection between the objects causes withdrawal of the piston (3) with consequent expansion of the volume of gas in reservoir (9) against atmospheric pressure and against pressure developed in reservoir (8) as a consequence of decrease of gas volume therein.