To be fair,
comfort can be a mixed bag for system safety, especially when humans are alone, safety critical and on weird schedules which can all be the case for train drivers (which is what I understand "locomotive engineer" to mean in this context) - because comfort is conducive to sleep.
One of the setups I come to almost expect in maritime accident reports is an officer taking a night watch, alone, while somewhat fatigued. Warm, dark, quiet. After a few hours the ship has drifted significantly off its intended course. For unknown reasons (the officer was probably asleep) no attempt is made to correct... When they do wake up, they often don't have good situational awareness, and their focus is on pretending nothing is wrong, even if they are in fact already in serious trouble and need all the help they can get.
Night-time railway accidents are less common in my country, perhaps because the relevant unions insist on proper "if you're too tired just go home you aren't fired" type rules to reduce fatigue errors, but I do recall a case where a freight driver was dipping in and out of consciousness. When he was conscious he could see a red lamp out of the window, signalling "Danger" ahead so he'd reduce the traction power. If he'd been less sleepy he'd have noticed those red lamps were not getting closer each time, they were moving gradually away from him. His train was on a steep climb, and he'd reduced power so much it was gently rolling backwards. Oops. Nobody died, that time.