from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A temporary watertight enclosure that is pumped dry to expose the bottom of a body of water so that construction, as of piers, may be undertaken.
- n. A watertight chamber attached to the side of a ship to facilitate repairs below the water line.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A temporary watertight structure that is pumped dry to enclose an area underwater and allow construction work on a ship, bridge, or rig to be carried out; a caisson.
- n. An empty space that acts as a protective barrier between two floors or bulkheads on a ship.
from the GNU version of the Collaborative International Dictionary of English
- n. See Cofferdam, in the Vocabulary.
- n. A water-tight inclosure, as of piles packed with clay, from which the water is pumped to expose the bottom (of a river, etc.) and permit the laying of foundations, building of piers, etc.
from The Century Dictionary and Cyclopedia
- n. A water-tight wooden inclosure built in a body of water, in order to obtain a firm and dry foundation for bridges, piers, etc., by pumping out the water from its interior.
- n. In a war-ship, one of a series of compartments. in the vicinity of the water-line above the protective deck, built in the interior against the ship's side or around hatches, forming a double wall, which can be packed to prevent water from entering the vessel after the side has been pierced by shot. In the United States navy the packing is made of the pith of corn-stalks. See def. 2.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. large watertight chamber used for construction under water
Sorry, no etymologies found.
With what had been thought to be the best immediate solution to contain the leak, a 78-ton steel and concrete box known as a cofferdam, resting useless on the sea floor, BP said the next best way to contain the oil could be in the form of a smaller containment dome.
The plan is to cover the leak in the structure known as a cofferdam, and funnel the oil to the surface.
The reason for the cofferdam was the release of extra water by the U.S.
What had been thought to be the best immediate solution to contain the leak, a 78-ton steel and concrete box known as a cofferdam that took two weeks to build, rested useless on the sea floor, and the gulf's fragile ecosystem seemed to be facing if not the worst case scenario, then one that was certainly very bad - an outpouring of oil that will go on for perhaps three more months before a relief well can intercept the leaking one and seal it.
This video shows the failed attempt over the weekend to lower a 100-ton, 4-story "cofferdam" dome over the top of the main leak.
The outer hull stops over 90 percent of any radiation; then comes the "cofferdam" (cargo holds and water tanks) which absorbs some more; then comes the inner hull which is actually the floor of the cylinder which is first-class passenger country.
Adam Gabbatt demonstrates how BP plans to use a 'cofferdam' to stem the flow of leaking oil from the Deepwater Horizon wellhead
Deepwater team attempts to put 'cofferdam' over blown-out oil well
BP has tried to control the flow by activating the sea-floor blowout preventer, a stack of valves which should have dealt with the problem in the first place, but was allegedly defective, and by lowering a "cofferdam" over the leak to funnel oil to ships at the surface.
British Petroleum crews successfully laid down the "cofferdam" late Friday over the largest of two leaks that continue to shoot 210,000 gallons of oil into the Gulf each day.