Back to the topic of How We Used to Railroad:
When we took siding in ABS territory and went to beans, we took the lead strap from a torpedo and stuck it upright into a rail joint, so that, when we returned, we would know if any train had passed, and could call the DS and find out which train(s) and compare them with our train orders. With almost no open train order offices, that's the only way we could tell which extras had been met when we were eating or whether the passenger train was displaying green signals.
CLARIFICATION: I just re-read what I wrote, and I think it could be misleading. The lead strap was just confirmation that some train had run on the main track while we were gone. It was the call from the phone booth to the DS that informed us what train had passed and if green signals had been displayed.
