cofferdam

• coffer-dam

coffer +‎ dam

cofferdam (plural cofferdams)

1. (engineering) A temporary watertight enclosure used to create a dry foundation for building bridges and other structures over water.
   • 1851, Herman Melville, Moby-Dick:

     He stood full six feet in height, with noble shoulders, and a chest like a coffer-dam.

   • 1992, Cormac McCarthy, All the Pretty Horses, →ISBN:

     Downstream there was a small wooden cofferdam and when he woke there were naked children splashing in the pool there and he rose and wrapped his jacket about his waist and walked out along the bank where he could sit and watch them.

   • 2020, Peiwen Xu, Miao Xu, Hongbo Lu, Longzhen Qiu, “Polyvinyl chloride gels microlens array with a well-controlled curvature obtained by solvent evaporation under DC electric fields”, in Optics Express‎, volume 28, number 20, →DOI, pages 29285–29295:

     At fixed injection volume of PVC gels solution, the curvature of MLAs [(microlens arrays)] obtained with patterned electrode substrates at fixed sizes of cofferdam can be tuned by changing the preparation voltage.

   • 2022 January 12, “Network News: First pier cast for HS2's Colne Valley Viaduct”, in RAIL, number 948, page 10:

     Where the viaduct crosses the lake, the piles will be bored directly into the lakebed, using a cofferdam to hold back the water while the pier is built.

2. (nautical) An empty space that acts as a protective barrier between two floors or bulkheads on a ship.
3. (introduced by dentist Sanford Christie Barnum, New York, in 1864, but after his century maintained only in other languages than English) A rubber dam to keep the teeth dry when operating upon them.
   • 1874 March 2, Edwin Sercombe, Esq., “Dental News and Critical Reports. Odontological Society of Great Britain. General monthly meeting and conversazione.”, in British Journal of Dental Science, volume 17, page 166:

     I refer to Dr. Barnum, who has given us the coffer-dam. I cannot detain you while I describe the immense benefit which his application of a very simple material has conferred on the public.

   • 1884, “Barnum’s rubber dam”, in The New England Journal of Dentistry, volume 3, number 1, pages 27–28:

     Dr. La Roche then first we are informed made the claim that he knew of and used rubber for a coffer dam prior to Barnum.

• caisson, a similar structure, but permanent in nature