Mammoet and Global Diving’s innovative deep water salvage operation in Canada


03-06-2009

Mammoet Salvage recently recovered a fuel truck loaded with diesel and a cabinet containing lube oil from Robson Bight near Vancouver Island in Canada. The challenging project, in a water depth of 360 meters, was completed on time and well within budget.

Project In August 2007, a barge lost a load of logging equipment, including a fuel truck loaded with 10,000 liters of diesel fuel and a cabinet containing 1000 liters of lube oil, in Robson Bight Ecological Reserve near Vancouver Island. The area is stunningly beautiful and an important habitat of orcas, seals, dolphins, migrating birds, juvenile salmon and other species. Hence nature conservation organizations, the local tourist industry and First Nations (Indian tribes) pressed the authorities to remove these pollutants. After a tender the Ministry of the Environment of British Columbia awarded the salvage project to Mammoet Salvage BV, the Netherlands, and its partner Global Diving and Salvage, Seattle, USA. All the parties involved in the project developed a complex scheduling matrix which considered the presence of animals, the weather, etc. The work was originally planned for November 2008 but was rescheduled to May 2009 because of the presence of whales in the area.

Containment As there was a real danger that the truck might leak fuel while being raised to the surface, Mammoet Salvage engineered a Deep Water Recovery Casing (DWRC) which was fitted over the truck to catch any escaping diesel. Two eight-tonne weights on the sea bed positioned guide cables for the DWRC. The truck was first aligned with the prevailing currents and the DWRC was then lowered over it and secured using an ROV (remote operated vehicle). The process was monitored using cameras on the ROV and inside the DWRC. On 19 May the fuel truck was successfully raised to just below the surface where the contents of the DWRC were checked for oil and inspected by divers. It was then placed inside a containment barrier on the Mammoet barge. The lube oil cabinet had been recovered a few days earlier.

Equipment and operations The salvage equipment, including a crane, was installed on a barge which was towed into position. The water depth in Robson Bight, up to 400 meters, presented a real challenge and required the use of four mooring winches with a total of 6 km of mooring lines. There were also strong currents which varied with the depth. The salvage team was on site for ten days and suffered two down days due to poor weather conditions. An environmental response team was available in case of emergencies. Because of the sensitive nature of the area there was great media interest in the project. Mammoet Salvage and Global Diving were proud to complete the project within the available time and under budget.

People The DWRC, on-deck containment and weights were engineered at the Mammoet Salvage head office in the Netherlands and built at Mammoet Canada Western in Edmonton. The team enjoyed working in this beautiful setting. The Canadian health and safety authorities visited the site on several occasions and were impressed by the strict safety standards.

Expertise

This was Mammoet Salvage’s first project in Canada. The aim was to deliver an innovative solution to improve safety, protect the environment and reduce costs. The project benefited from the company’s expertise with challenging jobs (e.g. the Russian Kursk submarine and the possible salvage of the U864 submarine with a toxic cargo). The team also learned more about the use of underwater containment equipment and these lessons will be valuable in future salvage projects.

Company

Mammoet Salvage BV is part of Mammoet Holding BV (heavy transport and lifting specialists) which was awarded the contract for the salvage of the Russian nuclear submarine Kursk in 2001. Since then Mammoet Salvage has carried out a range of salvage projects throughout the world. The company emphasizes innovative engineered solutions to improve safety and reduce costs.

 

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www.mammoetsalvage.com and www.mammoet.com

By Professional Mariner Staff