forepole

[ noun fawr-pohl, fohr-; verb fawr-pohl, fohr- ]
/ noun ˈfɔrˌpoʊl, ˈfoʊr-; verb fɔrˈpoʊl, foʊr- /
Mining.

noun

Also called spile, spill. any of a number of boards or timbers driven forward on top of a set to protect miners lengthening a tunnel from falling debris.

verb (used with object), fore·poled, fore·pol·ing.

to reinforce (the end of an excavated tunnel) with forepoles.

Origin of forepole

An Americanism dating back to 1870–75; fore- + pole1