The "TOWER WISHBONE MOORING SYSTEM" – a Bluewater concept, is particularly suited to marginal oil field developments in areas with moderate seas and shallow to medium water depths, or where exceptional conditions call for disconnection of the tanker at short notice. Such areas could be those where typhoons occur, or where icebergs or irregular ice coverage may endanger the tanker.
Application of a Tower Wishbone Mooring as a single point mooring for a storage or floating production system eliminates many of the drawbacks of previous SPMs. Those systems usually incorporated a CALM or SALM buoy with the tanker moored via a rigid arm. Elasticity was provided by the buoy's anchoring with the accompanying inconvenience of underwater articulations and/or flexible flowlines.
The Bluewater system is based on the principle of the tanker being moored to a rigid jacket via flexible yokes. Gravity weights incorporated in the yokes are suspended from the jacket via tension members attached to a turntable, thereby allowing the moored tanker to weathervane.