By the time the Coast Guard took over the project, damage to the vessel had caused it to buckle, and the stern sank. Workers pumped 500,000 gallons of river water into the hold of the 239-foot-long stern section to stabilize it and keep the barge from breaking up.
In late April, divers employed by Seattle-based Ballard Diving and Salvage cut the stern section free. Last Thursday, workers began pumping out the ballast water, and by Saturday the stern section was afloat and stable, said Coast Guard Capt. Daniel LeBlanc, the incident commander.
The most challenging part of the demolition will involve cutting away the double-bottom sections of the hull, where tanks are likely to be contaminated with heavy bunker oil. Because the barge’s midsection is submerged, divers will work underwater in the dark, in close quarters, as they cut up the sections with underwater torches. “Everything they do is by touch and feel,” LeBlanc said.
The Davy Crockett is encircled by a cofferdam composed of nearly 1,150 linear feet of metal sheet pilings and a secondary silt barrier, both anchored to the river bottom. Completed two and a half weeks ago, it’s designed to contain PCB-tainted oil and bunker fuel and prevent pollutants from escaping into the river.
A 150-foot “deflection” wall protects the cofferdam from river debris.
Contractors decided in late March to dismantle the Davy Crockett where it sits after officials failed to find a dry dock willing to accept the dismantled vessel cut in two pieces.