I've worked on both steam locomotives & diesels. I agree with Mr. Goldstein. It seemed like I got dirtier and it took a lot more work/scrubbing and time to get clean after working on diesels. Coal soot and steam cylinder oil and boiler scale come off a person a lot easier in my experience.
Funny story about carbon soot from large generator brushes- which will get a person as black as any chimney sweep:
Year ago at the powerplant, we were doing some maintenance and repair work on one of the 300 Mw hydroelectric generators. Specifically, we had rigged up an old lathe compound and were turning the slip rings in place, using the actual turbine to spin the whole unit. In essence, we had the world's biggest vertical lathe, having a potential of about 500,000 shaft HP, though we were only running with the wicket gates barely cracked open to get a little speed. With 257 rpm being normal synch speed, but with slip rings about 5 feet in diameter, we needed a much lower rpm to get the surface speed on the slip rings right for turning, even with carbide tools.
We were working away in the generator housing and due to the space heaters being turned on (to keep condensation from forming in the windings) it was HOT in there. We were all down to our tee shirts and sweating, but enjoying seeing the job of turning the slip rings coming off nicely. I had contributed the compound off a Seneca Falls lathe (ca 1905),and we had plenty to joke about that.
Meanwhile, the electricians were busy cleaning carbon dust, servicing the brush rigging and inspecting/replacing brushes. The electricians were getting a lot blacker than we were. We were joking up and back between the mechanical and electrical crews. One of the electricians was a good looking woman with a fine figure, in her 50's at the time, but undeniably a fox. This woman had worked as a bartender, tended to date men with fast/souped-up cars, and by her own admission was a "bad" or "wild" girl. She noted that I was nowhere near as dirty as the electricians and took a handful of carbon soot and smeared my face with it before I knew what hit me. The combined crews were howling with glee- I was the only person in management inside that generator. OK, I can take getting dirty, and I laughed along with everyone else. Then, that woman electrician decided my face needed washing since she had gotten it dirty. She began to peel up her sweaty tee shirt, showing off her hard belly and making all the moves one would associate with an exotic dancer. The whole crew was now howling and hollering encouragement. I outshouted the entire crew, ordering that woman to keep her tee shirt on and said I'd wash up in the mechanics' locker room, thank you very much. Talk about trouble ! Corporate had all kinds of policies about sexual harassment, and the deck normally is stacked against men in those sorts of situations. Even if the matter never reached corporate, I did not need trouble right there within our own powerplant. I thanked the lady for her kind offer of cleaning my face, and told her my wife (whom she had met and knew) would appreciate her concern but not her methods. We all settled down and got back to work. The story of the carbon soot and my declining the offer of having my face washed with that lady's tee shirt became a legend in the plant.
When I saw the youtube of the Brush locomotive and the fitter was demonstrating how easy/accessable the brushes on the generator were, I remembered the episode in our own generator with the carbon soot. We used to like to kid around a lot, and those were the days when we could. Corporate was constantly sending people up to the powerplants to preach about some new policy or other, sexual harassment being a major issue with them, along with political correctness and the like. We let it roll off our backs, in one ear and out the other. After 6 + years of retirement, I am back at the powerplant in a mentoring role. I daresay the environment has changed. Much more uptight than when I worked there, but then, about half the people I worked with also went out the gate into retirement. New workforce, new and tighter controls from corporate. Seems like when we'd work on the units we'd be yelling up and back, singing, joking, and really hitting it hard. Different times, newer generation, I guess. I still get kidded about the "face washing" and it's a story the old hands tell the young hands coming up in our plant. As for the lady who was so solicitous, she never made it into retirement. She died at 55, a few months shy of her retirement, due to cancer of the liver and pancreas. Whether it was too much exposure to solvents used in cleaning electrical gear, or whether it was too much wild living or some combination thereof is something we will never know. I went back to work in the plant and the lady's old working partners are still on the job and it saddened me to see them walking thru the plant without her. I guess anytime I handle generator brushes and get a little carbon soot on me, I hear her voice along with the crew's and it puts a smile on my face. Gotta love working with a good crew in a good plant.