SCHOOL'S OUT FOR THE SUMMER.
No, I didn't sound the horn!
The locomotive, from the East Troy Electric Railroad, is equipped with an extension cord. The reel holds several hundred feet of heavy-duty cable, and the pole below the window has a hook that goes over the trolley wire, permitting short moves onto sidings that don't have trolley wire.
The North Shore Line had two locomotives equipped with storage batteries. Those were able to move somewhat farther from the wire, and on at least two occasions, they helped a steam locomotive on a connecting railroad start a heavy train.