scratches head

Limited use unless somebody is wanting to defend a train itself from being taken intact.

Tracks can be monitored by light patrols, by aircraft, and in open flat lands anybody with binoculars can keep an eye on the tracks over long distances during daylight/clear days. Radio/telegraph can be used to report track damages to keep the train from derailing, though it would impede travel. Also, damaging the track can hurt a partisan's efforts in the long term as a civilian populace probably needs the supplies that trains move around. Piss off the civilians too much and they'll turn on partisans.