This sculpture of a Welsh miner and his pit pony by Terrance Plowright was made life size. Unfortunately this shot doesn't give a clear indication of what that size is, but note the size of the lumps of coal in relation to the miner.

The miner would be well under 5' tall which apparently was indeed quite common back at that time. Miners of small stature had a distinct advantage when it came to the limited clearances of some of the mine shafts.