A cofferdam is an enclosure built within a body of water to allow the enclosed area to be pumped out or drained.[1] This pumping creates a dry working environment so that the work can be carried out safely. Cofferdams are commonly used for construction or repair of permanent dams, oil platforms, bridge piers, etc., built within water. They also form an integral part of naval architecture.
These cofferdams are usually welded steel structures, with components consisting of sheet piles, wales, and cross braces. Such structures are usually dismantled after the construction work is completed.[2]
The origin of the word comes from coffer (originally from Latin cophinus meaning 'basket')[3] and dam from Proto-Germanic *dammaz meaning 'barrier across a stream of water to obstruct its flow and raise its level').[4]