If anyone can find a copy of the March 1979 Trains magazine, it has an entire section (7 pages) dedicated to "Ohio's Robot Railroad" (the Muskingum Electric). I was in Chicago this weekend and got a copy while visiting the Illinois Railway Museum in their used book store.
The railroad was completely unmanned. Trains ran in sets of one E-50 locomotive and 15 hoppers. Trains operated in a "push/pull" manner where the unpowered end consisted of a specially designed hopper car with airhorns, a headlight and other equipment mounted on it's front to allow for the push operation from the rear upon returning to the coal tipple for new loads.
The two trains used a loop track at the loading tipple to load, and automatically slowed to 1/3 of a mph for the loading sequence. E50 #100 always used the west loop track while #200 used the east loop track to avoid any collisions.
Truck-mounted shoes on the hoppers picked up signals to control hopper door opening and closing at the unloading trestle. Command signals placed every 50 feet between the rails controlled train movements (such as speed, etc) on it's 30 mile round trip.
Really is an interesting article that tells you about anything you wanted to know regarding this railroad (except for the abandonment info obviously).
If anyone would like a copy, let me know. I can probably send a couple out by mail (although I can't guarantee overnight service between work and college course hours