noun
caisson
KAY-sahn/ˈkeɪsɑːn/
A watertight structure used in construction or operation below water.
The caisson keeps its working chamber dry beneath the river.
Etymology
The original “large box” image connects the word to its construction sense: a caisson is a boxlike enclosure made watertight for work underwater.
In context
without releasing the compressed air that was keeping the river out of the working chamber. The caisson above him was a steel cylinder approximately 40 ft in diameter.
More examples
- The caisson keeps water out of the construction area.
- A floating caisson closes the entrance to the dry dock.
- Several concrete caissons support the offshore structure.
Forms
caisson · caissons
Similar words
- cofferdam
- A temporary enclosure keeping water out, while a caisson can remain part of the structure.