caisson

American  

[key-suhn, -son] / ˈkeɪ sən, -sɒn /

noun

1. a structure used in underwater work, consisting of an airtight chamber, open at the bottom and containing air under sufficient pressure to exclude the water.

2. a boatlike structure used as a gate for a dock or the like.

3. Nautical.

   1. Also called camel, pontoon.  a float for raising a sunken vessel, sunk beside the vessel, made fast to it, and then pumped out to make it buoyant.

   2. a watertight structure built against a damaged area of a hull to render the hull watertight; cofferdam.

4. a two-wheeled wagon, used for carrying artillery ammunition.

5. an ammunition chest.

6. a wooden chest containing bombs or explosives, used formerly as a mine.

7. Architecture.  coffer.

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caisson British  

/ ˈkeɪsən, kəˈsuːn /

noun

1. a watertight chamber open at the bottom and containing air under pressure, used to carry out construction work under water

2. a similar unpressurized chamber

3. a watertight float filled with air, used to raise sunken ships See also camel

4. a watertight structure placed across the entrance of a basin, dry dock, etc, to exclude water from it

5. 1. a box containing explosives, formerly used as a mine

   2. an ammunition chest

   3. a two-wheeled vehicle containing an ammunition chest

6. another name for coffer

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Other Word Forms

• caissoned adjective

Etymology

Origin of caisson

1695–1705; < French, Middle French < Old Provençal, equivalent to caissa box ( case ² ) + -on augmentative suffix

Example Sentences

For years, members of the tiny preservation society — their ages now ranging from 60s to 80s — have flown out in helicopters, landing on the caisson.

From Los Angeles Times

Carolla visited a construction site on the beach that was installing 30 caissons six stories deep into the ground.

From Los Angeles Times

In 2021, workers started drilling underground through two major railway systems—the Metro-North Railroad and the Long Island Rail Road—and installing caissons 100 feet into the bedrock.

From The Wall Street Journal

Eyer’s body in a flag-draped coffin was brought from police headquarters on a horse-drawn caisson three blocks to the church where the late evangelist Billy Graham held his first crusade.

From Seattle Times

The service is also getting lighter-weight caissons and conducting more extensive training for the soldiers to ride and take care of the horses.

From Seattle Times