The New Student's Reference Work/Pile-Driver
Pile-Driver, a machine for driving piles. The ordinary form consists of a heavy iron weight which can be raised vertically from 10 to 40 feet between upright guides and then be released to fall on the pile beneath. The common weight of the ram is from 1,000 to 2,000 pounds, but weights of 4,000 pounds and over are occasionally used. It usually is lifted by a wire-rope, which is wound on a drum revolved by a small steam-engine, the ram being released when the desired height is reached. In the Vulcan-Nasmyth steam pile-driver a hammer is attached directly to the rod of a piston which works in a vertical steam cylinder. The admission of the steam to the cylinder causes reciprocating hammering, the number and character of the blows being regulated by an adjustable valve-gear. Another form of pile-driver is the gunpowder pile. In this the explosive force of gunpowder confined in a suitable mortar is used to drive the pile.