DCHP-3

double-jacking

[< double + jack fellow, laborer]
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This entry may contain outdated or offensive information, terms, and examples.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 method of drilling in which one man strikes with a double-jack a drill-steel held and rotated by his mate.

Quotations

1944
[Caption] Double-jacking. Drilling a down hole with an 8-pound hammer.
1963
There were no Yukon engines to create compressed air. Double jacking was the order of the day, the heavy sledges driving steel deep into the native rock.