DCHP-3

single-jack

Mining
DCHP-1 (pre-1967)

Entry from the DCHP-1 (pre-1967)

This entry may contain outdated or offensive information, terms, and examples.

n.

a relatively small hammer used in single jacking.

Quotations

1961
The mechanization of mines in 1890--the replacing of hand-steel, single jack and double jack, by drilling machines--had created new problems. . . .
1964
The miner, working either a double-jack or single jack job, might worry about the sprags. . . .