Recovery and Changeout of SUTU at 33m depth
EMEC is the European Marine Energy Centre, which is based in Orkney. It encompasses several tidal energy test sites including grid-connected tidal turbines and wave test sites, located at Warness. This site was chosen because of its high velocity marine currents which can reach 7-8 knots at spring tides in the natural channel between the Atlantic and North Sea. Such conditions necessitate the use of a highly experienced dive team.
EMEC’s test sites are connected by an underwater infrastructure, which terminates in a four mooring SUTU at Warness. The SUTU is a critical subsea system that allows many subsea control modules to be connected to the same communications, electrical and hydraulic supply lines. The Warness SUTU had developed a serious fault that required urgent repair.
RockSalt were contacted to undertake the diving work after the previous contractor was no longer involved in the project. The RockSalt dive team were mobilised to disconnect the SUTU and return to the surface for the client to conduct the necessary repair works. Once the repairs had been completed, the dive team returned the unit to the seabed and completed the necessary connections.
Surface Supplied Air Diving was carried out from the Green Marine Green Isle diving support vessel. This was mobilised from the quayside at Kirkwall Harbour. The dive system consisted of a 2-diver air panel, breathing from passive air banks installed on the vessel.
The biggest challenge on this project were the poor tidal conditions which restricted the diving window down to a handful of minutes to complete the dive works in returning the SUTU to the seabed. Fortunately, our highly skilled divers were able to complete the project successfully in difficult diving conditions.
Scope:
Recovery and changeout of SUTU at 33m depth.
