Locomotive left running

Locomotive engines by their nature aren't absolutely watertight. They leak a bit of coolant water into the crankcase. Plain water is boiled off and goes out the vent with no harm done whereas antifreeze would mix with the lubricating oil, destroying its properties. Antifreeze in oil leads to main and rod bearing failures including the possibility of seizures.

EMD engines had/have an automatic (temperature sensing) coolant drain valve such that if coolant temp approaches freezing it opens and dumps the cooling water. 

Lew

In 1984, When I ran a diesel (ALCO RS1 8669) on excursions at TVRM, I would put the reverse lever in neutral and remove the handle, while taking a break in the stations. I do not remember if the throttle handle was also removable as well, but the engine was secure, without having to lock the cab doors. The 8669 had six-wheel trucks and a Euro-style slanted cab side for use on the Trans-Iranian Railway during WW II to ferry supplies to Russia, our then ally.

During the eleven weeks of loco service in the Summer of 1984, I primarily ran and fired 2-8-0 Ex SR 722, but when the 722 required its monthly boiler flush, my substitute engine was the venerable, vintage RS1 8669 (1938?), and it was,a nice break from coal firing. Operating a steam loco vs a diesel is analagous to operating a standard shift car vs an automatic. The interplay between the throttle and the power reverse, which adjusted the valve stroke, required constant vigilance so as not to work the engine too hard, whereas the diesel could simply be put into a particular run, and it would automatically transition to that setting. We had an old style, non-self lapping brakestand on the 8669, which required attention the same as on the 722.

All the above could be correct.

Cooling system is the primary reason. But I would think this unit would have antifreeze in it. Before the EPA got all over the RR's they left most of them running 24/7 I remember down in the Southern yard they would all be sitting there running ready for anyone who called. Aired up and ready to roll. I was also told a lot of the older motors were better off left running so it would not suffer the stress of starting. they would run there entire life. White motors recommended to leave them running on generator/ compressor plants. And again if the engine had an issue with a cylinder leak as noted above you want to keep it running, but someone needs to keep an eye out for low fluid levels. 

Or the guy simply was told someone was coming for it and to leave it running, and or forgot to shut it down. As noted above the reverser level can be pulled so it wont move. 

Can some of the newer, smaller prime movets for gensets take antifreeze?

WRT emissions railroads are installing automatic cooling system heaters to keep coolant from freezing so the engine can be shut down when sitting idle.

https://www.hotstart.com/markets/railroad/

Lew

Anything less then 45* we do not shut them down. 

No concern over diesel gelling, if they are shut down in cooler weather??

Mike Wyatt posted:

No concern over diesel gelling, if they are shut down in cooler weather??

That’s another concern, yes. 

Usually they are left running in the winter to prevent the diesel gelling and coolant water freezing, but NS has started using locomotives that can be plugged into an outlet type object. (SD33ECo and GP33ECos)