(by flexible hours I mean he has no sleep schedule and may have to work 12+ hour shifts at any time of the day, with the possibility of a 8 hour break and another 12 hour shift)
If so sign me up! :D
"Mechanical engineering is the discipline that applies engineering, physics, engineering mathematics, and materials science principles to design, analyze, manufacture, and maintain mechanical systems. It is one of the oldest and broadest of the engineering disciplines. " https://en.wikipedia.org/wiki/Mechanical_engineering
My father was one, but designed gas compressors for oil & gas industry.
Locomotive Engineer's basically are the one in charge of operating the locomotive. What most people think of as a "Conductor" is actually a lower level job and is mostly paper work from what I hear.
Source: Close friend is a Locomotive Engineer in Canada.
All my explanations would be the "realistic" but kinda sarcastic answers.
Computer Engineer - Copy's pastes code until it works.
Rocket Scientists - Spend 50% of the time designing rockets, and 50% of their time hoping the rocket doesn't explode.
Locomotive Engineer - Whoops this isn't a real engineer! /s /s