An oil salvage operation is underway on the fragile wreckage of a U.S. army transport ship that sank almost 80 years ago off coastal British Columbia in a race to head off an eruption of thousands of litres of oil that a coast guard official says is “near imminent.”
The Canadian Coast Guard said the 77-metre-long Brigadier General M.G. Zalinski has been burping up “slow but consistent drops of oil” since the fall of 2022 at the shipwreck site in Grenville Channel, part of the Inside Passage off northern B.C.
Jeff Brady, superintendent of marine environmental hazard response in the west for the coast guard, said the discovery comes after 44,000 litres of heavy fuel oil and 319,000 litres of oily water was successfully extracted from the sunken ship in 2013.
An assessment done by the coast guard last year suggests about 27,000 litres of oil remains within the ship, which sits on a rocky shelf about 40 meters below the surface.
Brady said the oil removal work is urgent.
“We’re really well aware of that the marine mammals in the area, aquaculture, all the migratory birds.
“And what we do know about the wreck is that it’s in a deteriorated state, and it’s near imminent that we’re going to have a more significant release from it, and that’s why we’re aggressively launching this operation,” said Brady.
Coast guard crews began diving down to the site — about 1,100 kilometres north of Vancouver along the coast — for more than a week to do safety checks and prepare it for oil removal work, he said.
Built in 1919 by the American Ship Building Co., the Zalinski was initially used as a cargo ship, and in 1941, it was taken over by the U.S. Department of War to an army transport vessel.
The Zalinski was on its way from Seattle to Whittier, Alaska, in 1946, loaded with army supplies and about 700 tonnes of fuel, when it crashed into rock near Pitt Island.
It sank in just 20 minutes, although the 48 crew members aboard were rescued by a nearby tug and a cargo ship.
Since then, Brady said the wreck has been “very slowly” spilling oil.
The sunken ship was mostly forgotten until around 2005, when oil was reported in the channel, he said.
“And during that dive, to our surprise, we found a large Second World War wreck and that really started this progress,” said Brady.
The federal government awarded a $4.9 million contract to U.S.-based company Resolve Marine in October to use an extraction method called “hot tapping” to remove the fuel, the coast guard said in a statement.
Brady said a crew has cut a 10-centimetre hole in the steel plate of the wreckage without spilling any of the oil inside.