I thought the rods moved also, looked like a lever of some type to change direction when they left the tower.
For those not familiar with air switches, look up the DA10 by us&s (or its modern equal the quick switch from AAA). There is a modern version of this in many hump yards today on BNSF that would include Argentine ks, Galesburg il (until last year), bartow ca, gm yard (Oklahoma city), Flynn yard (Oklahoma City). Also inflat yards such as Cicero Il and Barstow CA NX system (receiving departure yards).