They weren't "conductors", they were "engineers".
Another factor that is seldom talked about is that crews in commuter service often have very early reporting times -- 6.00am, 5.30am, 5.00am, or even earlier. A routine like that can take its toll, particularly if the job has "release time" involved (where a crew reports, works around 4 hours, takes a "swing" for 4 hours, then comes back for more work.
And this doesn't include the "time getting to work" for some railroaders. I seldom had a job in which I didn't have at least an hour's driving time to the terminal. And of course, that much time getting home after work.
I never cared for the early-report jobs. And I didn't have sleep apnea. But after being awaked (by phone) by the crew dispatcher at 2.30am, then leaving the house at 4.30 for a 5.30am report, by 9 or 10 in the morning I'd find myself ready to nod off.
That's why as soon as I had enough seniority to hold them, I'd work "second shift" jobs. No need to get up and rush to work. No fight with rush hour traffic. Felt my best going to work 2.30-4.30 in the afternoon, getting done 9.30-midnight. No traffic going home. No rush to get up, could set alarm for 8-9am. And a good part of the day free to get things done.