Chicago Trains

Posthip Scott sent me this link to a story about an ancient railroad switch control system that is still in use. NBC has a pretty good video summary.

Metra’s 'tower' at the A2 interlock, built 1907.
Metra must be the new name for the Chicago Transit Authority

Switch control system, installed in the tower in 1932.

This machine was state of the art way back when. It's fiendishly complex and was no doubt custom built for this application. The company that made it made similar equipment for other railyards, but every configuration is unique. BroadwayLion has an explanation of how these things are operated (last post on the page).  I think the actual switching is done with pneumatics.

Small, gnarly portion of the railroad switches controlled by the Tower.