Say what you will about the complexity of modern machines - often a fair criticism - I've noticed a LOT MORE thought goes into maintenance on say, newer vehicles than old relics. I wouldn't doubt that applies to old diesel locomotives vs the new diesel-electric pushers, for example. The latter may have more stuff to go wrong, but the stuff that commonly goes wrong is easier to get to overall. I watch a lot of classic car restoration and customization shows (anxiety precludes me from watching other sorts of television due to drama) and what I've seen from 80 year old cars - regardless of condition - would curl your hair in terms of servicing them, and that's not accounting for not being able find parts. :~
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix