I was playing "Hostler" that day. It is a mechanical dept. position. I did all the oiling, greasing, clean and rebuild the fire stuff, get coal, etc. When done, I turned it over to the road crew and tied up for the day...
Never wear a nice hat when you have to stick your head into the machinery.
BTW, Strasburg offers a Hostler Tour where you spend the morning hanging around watching someone (like me) get the engine ready for service. Along the way the tour guide explains what it is we're supposedly doing, and talks about steam locomotive mechanics, etc. It's a pretty neat deal and rather popular.