System for quick release of mooring and loading and unloading lines between a loading and unloading station at sea and a vessel

A system for quick release of mooring, loading and unloading lines between a station at sea and a vessel during heave motions, wherein the station is a loading and unloading station comprising a swivel and wherein the system comprises:

• a rigid yoke connected to a lower part of the loading and unloading station and being rotable around:
• a vertical z-axis going through the loading and unloading station,
• a horizontal x-axis in the length direction of the rigid yoke and
• a horizontal y-axis orthogonal to the horizontal x-axis, and
• wherein the rigid yoke has a heavy section at an outer end of the rigid yoke;
• at least two mooring tethers, for connection between the outer end of the rigid yoke and the vessel;
• at least one loading or unloading line connected to a swivel on the holding and unloading station being rotable around the same vertical z-axis as the rigid yoke;
• mooring cradles each mounted on a mooring arm on the vessel for connecting the at least two mooring tethers to a bow or a stern of the vessel;
• a winch line connected to an upper end of each of the at least two mooring tethers;
• connectors for connecting the mooring, loading, and unloading lines to the vessel;
• and
• a winch arrangement for handling the at least two mooring tethers and the winch line;
• the winch arrangement being arranged for a pay-out speed of the at least two mooring tethers to be lower when the vessel, at the position of the mooring cradles, is moving downwards and for the pay-out speed to be higher when moving upwards, based on measuring tension on the at least two mooring tethers,
• the winch arrangement being switchable from a hold-back capacity of an entire yoke assembly, including the rigid yoke and the at least two mooring tethers, to a hold-back capacity of the at least two mooring tethers only, when the rigid yoke has landed on the sea floor and fenders to absorb impact energy at the bottom of the rigid yoke.