cofferdam

[ kaw-fer-dam, kof-er- ]

noun

1. a watertight enclosure placed or constructed in waterlogged soil or under water and pumped dry so that construction or repairs can proceed under normal conditions.
2. Nautical. a sealed void between two bulkheads, as for insulation or as an extra barrier to the escape of liquids or vapors.

cofferdam

/ ˈkɒfəˌdæm /

noun

1. a watertight structure, usually of sheet piling, that encloses an area under water, pumped dry to enable construction work to be carried out. Below a certain depth a caisson is required
2. (on a ship) a compartment separating two bulkheads or floors, as for insulation or to serve as a barrier against the escape of gas or oil

Word History and Origins

Origin of cofferdam¹

First recorded in 1730–40; coffer + dam ¹

Example Sentences

That included the construction of a huge temporary cofferdam to divert the thundering water from the building site.

From Washington Post

A cofferdam allows water to be pumped out, creating a dry area for land reclamation work to proceed.

From BBC

The exercise began with its easiest assignment - mapping the underwater remains of the steel cofferdam where Broadwater and other archaeologists excavated the wreck of the British supply ship Betsy in the 1980s.

From Washington Times

With no interpretive signage, it draws scant attention from anglers who beach boats along the crumbling old cofferdam, then cast for trout in the still pool inside.

From Seattle Times

By early August 1912, the waterproof cofferdam was built and the pit within dredged and pumped free of water.

From Seattle Times