This is the Beamish Mine Museum we were at in 2011. The miners had a board they would lay on as there was water running though the mine. They would have to swing the pick and then shovel out the coal. The each had a oil lamp (used to be a candle which they had to pay for) and each lamp has a number on it. At the end of shift the lamps were put on the rack and if one was missing then they would search for the guy in case of a cave in.