The Finger Lake Live Steamers has a single track area on their 1" 1:12 track that might work in areas on both Bob’s and the IPP&WRR. The engineer hits a switch that gives him a green signal as he enters the trackage and that presents a red signal at the other end of the single track. When he arrives at the other end, he must turn the signal off. These switches are at each end and requires two poles for turning the signals on and two for turning them off. They stay dark when not in use.
Not certain how and where Bob would like to use them, but on the IPP&WRR, the trackage going under St. Helen’s running from Peter’s Pond to the long lead climbing to Bell might be a candidate. The new short passing siding along the back fence has alleviated some of the concern and, of course, a dispatcher controls this trackage when they are doing their job.
If the wiring was being put in, I guess you could also have it controlled from the Dispatcher’s Office, when they are in attendance, and then switched to manual operations by the engineer or operator, when a Dispatcher is not present.
I think the EBT did something like this controlling the doors to the tunnels. And think there were some pranks played that also took down the tunnel doors. 
