Oceans of knowledge
Soft Yoke Wishbone SPM Tower system
The single point mooring tower with a soft yoke wishbone system includes a rigid steel frame that is connected to the tower by means of hinges and to the vessel by means of a pendulum structure.
This requires a dedicated vessel as its hull is modified to support the pendulum structure. Typically the pendulum structure includes two pendulums that provide a restoring force when the vessel moves away from the neutral position relative to the buoy. This restoring force maximises the range of local environmental conditions in which the SPM system can moor a vessel.
Typically the soft yoke consists of a ballast weight attached to a chain or a rigid steel member with uni-joints on both ends. In ice-covered waters, the ballast weight remains above the water, while in other conditions the ballast weight can be submerged taking advantage of the hydrodynamic friction to dampen the pendulum motions.
The soft yoke system can also be combined with a fluid and/or electrical power transfer system for F(P)SO applications. The fluid path between tower and the dedicated F(P)SO is realised by means of jumper hoses and/or jumper cables. The soft yoke system can even be provided with the option to allow for disconnection at the tower to enable fast installation or enable disconnection for extreme events like heavy ice loads.