How long can diesel locomotive theoretically last given if all the spare parts are available and the owner is willing to do continued major overhauls? I know the locomotive life span is between 15-25 years, but that is kind of vague considering mileage and the type of work is not taken into consideration. What does class I use as metric as to determine when a locomotive should be retired/scrapped? I hope to not get into a GE vs EMD debate as to which one last longer, but in general what would eventually force a engine to retire if overhaul can be done? Is it cracked frame, engine block or etc...? thanks
engine blocks get replaced all time, but any frame damage will bring end to a locomotive , be it from damage, metal fatigue , rust, etc.
there are locomotives in service of 60 years and better, maybe not in class 1 service , but on short lines and in passenger service.
It really all depends on if owner is still willing to spend money on it or it is part of historical significance.