A 40-foot steel structure used for oil and gas exploration in the Beaufort Delta has been moved for the first time in decades.
Known as a “caisson retained island,” the structure was originally built in the 1970s for offshore drilling, according to the N.W.T. Department of Infrastructure. When placed on the sea bed in shallow water, it would provide a stable base for a drilling rig.
It was anchored in the harbour at Tuktoyaktuk, N.W.T., in 1989. It sat there until a few years ago, when a storm broke it free and it beached.
Marine Recycling Corporation (MRC), a salvage company from Ontario, was hired last year to move the unit. The company came up with a plan and executed it this past month.
The caisson weighs approximately 12,000 tons, which meant MRC needed help to move it.
Terry Camsell, the director of the N.W.T. government’s Marine Transportation Services (MTS), said salvagers worked with local leaders and companies to think of a solution.
“It’s not as if you can go in there with a couple of tugs and pull it out,” said Camsell.
Camsell said the salvage crews scheduled the arrival of two tug boats owned by MTS. Together with the tugs, the crews were able to move the caisson off the beach and across the harbour, where they secured it to a dock close to the MTS yard in Tuktoyaktuk.
The crews at Marine Recycling Corporation ran tow lines to shore that were nine inches in diameter. Chain tensioners were used to pull with 2,000 tons of force to move the caisson away from the shore where it had been beached for the last three years. At that time, a storm surge had broken the anchor lines that kept the structure in the middle of the harbour.
“It’s good to see it floating again and the community is really happy,” said Darrel Nasogaluak, the chair of the Tuktoyaktuk Community Corporation.
“Even on social media, I see posts about people saying they have their view back, of the harbour.”
Nasogaluak said people have been driving up to the new location, which is an old dock used by oil and gas companies.
“It’s one of the last things left from the ’60s and ’70s oil boom, that’s kind of been an eyesore in the community,” he said.
Jordan Elliott, the project manager with MRC and the company’s president, said the plan is to use the metal from the caisson to strengthen the docks in the harbour.
The former owner left residual fuel in the tanks of the caisson. Elliott said the oil will be burned by a local company for heating fuel this winter.
Crews are working this month to ballast the caisson to the bottom of the harbour where it is currently sitting, and where it will be dismantled into eight parts.
Before the metal can be used for dock materials, the project must be approved by local regulatory boards.
“There are a lot of permitting requirements when building docks and infilling harbours and that,” said Elliott.
No timeline was given on when the dock work would begin.
Camsell said the caisson was not the last structure still left abandoned in the N.W.T.
A steel drilling caisson, a super tanker sitting on an inverted barge underwater, is still in the Beaufort Sea.
“That is still sitting off of Stokes Point, close to Herschel Island — there has been some discussion for years about what to do with that,” said Camsell.
A company in Norway owns the offshore drilling rig. Camsell said there have been talks with the company about what to do with it.
“They want to sell it, or they will have to take it out and scrap it. That is something they are responsible for,” said Camsell.
“It weighs more than the Tuk harbour caisson, so it will be much more work.”
