Acergy approached Orwell offshore for the provision of a Towmaster to oversee the offloading and towage to location of the Detachable Turret Mooring (DTM) buoy for the Apache Van Gogh project in the Exmouth sub-basin off the coast of Western Australia.

A Towmaster was assigned to assist the project.  The work scope included review and assistance in developing procedures, attendance at HIRAs, audit and suitability surveys of tugs and attendance on board the lead tug for the towage of the buoy to location until handover to the installation vessel.

The DTM Buoy was discharged from the heavy lift vessel “Fairlane” in sheltered waters off Exmouth Gulf and towed to location by the tugs “Day Tide” and “Mermaid Sentinel”. It was submerged to the installation depth and handed over to the installation vessel “Toisa Proteus”.

Various complexities were encountered on the project, such as the requirement of a continuous weather window with significant seas below 2.6m from discharge of the buoy until the buoy was submerged to installation depth; the limitation of the maximum bollard pull that could be applied while towing and the handling of the clump weight chain which was attached underneath the buoy.

The early appointment of a Towmaster, together with the project being followed through to its conclusion by the same person, will have contributed to its successful completion.