The Probert Encyclopaedia of Warfare

CAISSON

A caisson is a chest used to hold ammunition. The term became applied to a four-wheeled carriage for conveying ammunition, consisting of two parts, a body and a limber around the beginning of the 20th century. The name caisson was applied to a form of early landmine consisting of a chest filled with explosive materials, to be laid in the way of an enemy and exploded on his approach.
Research Caisson