Bute-Cumbrae

Utility ROV Services were contracted by Briggs Marine Contractors Ltd to conduct cable burial operations of a 33kV subsea cable between Bute and Cumbrae. The cable was lowered 0.8m below the mean seabed level over a distance of 4.9km by the controlled flow excavation (CFE) tool.

UTROV® System 2 was mobilised onboard the DP2 vessel, MV Elektron, as part of the cable installation spread. Following the installation of the cable, burial operations were performed.

UTROV® operators maintained continual communication with the crane operator during the operations to maintain the correct altitude with the CFE to provide the desired depth of burial. Tritech Gemini Narrow Beam Imagers were used to monitor the cable position ahead of the vehicle and its burial depth behind the vehicle. Online survey and UTROV® operators maintained the CFE over the cable RPL using a combination of vessel moves and thruster commands. Due to the variation in seabed conditions (silt/mud/clay), the CFE propeller speed had to be adaptive to ensure the correct burial depth was achieved.