Third rail and a massive electric motor plus realistic chuffing sound?
Worked on mines (coal, gold, uranium) and been down loads (lead, potash, salt, copper etc). Nasty, horrible places to work in. But if you are up for it, also amazing. Personally would never fight so my kids could work down one.......
One idea - reworking and extracting coal from old tips? Has been done commercially previously in the UK but I'm pretty confident that there is still coal left in old tips about the place. Gets rid of the old mine waste, keeps your steam loco going.....just a thought......need a mining engineers thoughts.