I'm sure miners do get used to the confined space. I've only spent one shift below ground, and the initial horror gave way to some sense of normality.

I supervised a pipejack under a railway line - the 3ft diameter pipe was about 10ft below ground and was gradually pushed under the line with hydraulic jacks. To make this work, someone has to dig out the ground in front of the pipe. We had an ex-miner do the job. He went in at 8am and came out at 4pm each day. He ate his lunch where he was working, and wouldn't come out. The maximum distance was 25 yards!

Phil