The Outrigger Buoy is a catenary moored offshore structure solution. Pitch and roll stability is achieved by using inertial masses to increase the natural period to out with the wave period of the highest and most energetic seas, up to and in excess of 25 seconds.
The internal masses are set at an appropriate pitch radius from the buoy centreline to not only dampen the motions and adjust the natural period separately for both pitch and heave. The inertial masses can also be used to stabilise the buoy during load-out and can have ballast chambers fitted to give fine trim adjustment in operation.
This arrangement allows great flexibility in the design and can be used in shallow water and aggressive environments, with designs having been analysed up to Hs 19m (the highest seas ever recorded in 2013 in the North Atlantic).