said by Jack_in_VA:Until recently diesel railroad engines were never shut down. Sometimes they would sit and idle for hours. Now they do shut them down because of fuel costs.
Railroads prefer to keep locomotives idling for two reasons, the primary one being a warm engine is a bear to restart and second beeze if there is a possibility of the temps dropping below 32 the engineer is required to dump the cooling water out of the engine when tying it down if the locomotive is not equipped with temperature controlled dump valves.
Either way the cooling system must be refilled before firing the locomotive back up which is not only a time consuming process it requires a ready supply of clean water and lots of it, heck a basic locomotive such as a GP-40 requires 254 gallons of cooling water.
Hence the reason so many locomotives are tied down with the reverser removed and left to idle when not in service.
And as a foamer I can assure you when it comes to wet stacking, pffft, even after day of idling that is not a problem.
Wayne