As a former volunteer fire fighter I offer the following: The first rule when attacking a fire is to save lives. The second is to prevent further exposure, and the third, and final, is to extinguish the fire.
On more than one occasion, being in a rural department, we came on a scene where the primary structure was beyond saving with our limited resources. So we would concentrate on preventing further exposure. On at least one occasion this led to some difficulties with the property owner.
On one occasion we were called out on a structure fire in a small cabin closely surrouded by trees. When we arrived it was obvious that the structure was gone, and we immediately started hosing down the surrounding area to keep the fire contained. The property owner, who was there, was very irate and couldn't understand why we weren't concentrating on his cabin. We never did convince him.
In this present instance, would it have been wiser to concentrate the fire fighting efforts on protecting the historical RR equipment? Not being there I won't presume to second guess the incident commander's judgment. All I'm trying to do is to point out that early on in a fire there are judgement calls which have to be made which early on which strongly affect the eventual outcome of the fire fighting efforts.
There are a lot of unknowns here.
CJ