Do we have any coal miners on the forum?

I worked 22 years for Joy Mining Machinery. Warrendale,PA Assembly /Repair shop. We built and repaired long wall equipment. 90% was in the shop. 10% we had to go underground mostly for warranty work. Usually welding but sometimes changing hydraulic parts. Usually Southwest PA, West Virginia or Ohio.
Google Longwall mining… you’ll be amazed how high tech and productive it is.