PORTLAND, Ore. — The Unified Command for operations to remove the barge Davy Crockett from the Columbia River will begin construction of a cofferdam around the vessel Friday.
Contractors working on the response are mobilizing equipment and materials to construct the cofferdam that will completely encircle the Davy Crockett and allow the barge to be dismantled in place while minimizing the pollution threat. It is expected the construction of the barrier will take approximately 12 days.
When completed, the cofferdam will stretch 850-feet around the barge and extend approximately 18 feet above the river bed. A geo-textile silt barrier will line the inside of the sheet pile. This barrier will keep pollution inside the cofferdam, but additional oil skimmers and 800-feet of boom will be deployed down river from the area as a safeguard against any pollutants that may escape the barrier. A vibratory method of installing the sheet piles will be used in place of an impact driver to cut down on noise pollution and disruption to natural resources and residents near the worksite.
Sections of the Davy Crockett will then be cut away, dismantled and removed from the river by barge. Dewatering and recovery of pollutants will take place before any section of the ship is dismantled or placed onto a barge. Some pieces of the Davy Crockett will be cleaned on a materials barge outside the cofferdam.
The decision to construct the cofferdam was reached after negotiations with two local shipyards to dismantle the Davy Crockett failed March 21. The Unified Command also explored and exhausted other options before deciding this is the best remaining method for removing the barge.
“The Coast Guard, Washington Department of Ecology and Oregon Department of Environmental Quality along with civilian contractors are working together to remove the Davy Crockett in the safest method available to our workers, the environment and to those who live and work along the Columbia River,” said Capt. Daniel LeBlanc, Coast Guard Marine Safety Unit Portland Commander.
For more information regarding the response, please visit the Davy Crockett response website.