How to totally destroy a rail line? Of course the amazing work of taking out a train is a big accomplishment. But how to remove rail as an option?

Bridges and such can be targeted but entire rail track are too small to effectively attack with bombs.

So ok creat a drone that runs down the track dropping beacons that guide bombs to them. Ideally take out a mile or so of track where repair crews can be targeted.

… just wishing for a faster end to this war.