A method of sinking a shaft through wet clay, sand, or mud down to firm strata.
Cast-iron tubbing, attached ring by ring on the surface, is gradually lowered
as the shaft is excavated. There is a special airtight working chamber at the
bottom of the lining. A cutting shoe at the lower end of the tubbing helps it
to penetrate the soft ground. The caisson method is obsolescent, being replaced
by the freezing method, etc. See also: concrete
caisson sinking Nelson
Dictionary of Mining, Mineral, and Related Terms