To be at the coalface means to be on the front lines–working at a practical level, rather than a theoretical one. The phrase is primarily British, and derives from the image of coal miners having direct contact with exposed ore. This is part of a...
punch mine  n.— «The museum is a history lesson of Wheatcroft’s rich coal-mining past.…Clark shows a picture of a stooped miner entering a punch mine.» —“Mining a father’s passion” by Garret Mathews in Wheatcroft Louisville Courier &...
grit pit  n.— «Grit pits are pits about 10-feet-by-10-feet wide that run under main sewer lines and catch debris filtered through the main line. The purpose of the plastic-walled pit is to collect debris that would normally accumulate inside the...
