This next update are some photos of Infomat – a Pullman car space reservation scheme developed for the PRR by US&S in the early 1950’s:
The PRR logo is a nice touch.
Some close-ups up of the relay apparatus in the back show step-by-step switches, along with cases of type L relays and a KP line relay for the coding equipment perhaps.
To find circuit plans for this would be a real treat – if they even exist anymore?
Note how the bundle of wires in the upper left hand corner grows in size as each row of vertical wires from the front panel joins it. Imagine how much time and patience it took wire something like this… All in a days work back then.
I know its a long shot, but if anyone has any details, photos of this system in service, pamphlet U-5134, or even any recollection of how it worked – please share. Thanks! -Rich
UPDATE: More discussion here and US Patent 2622142 info here. A look at the circuit diagrams reveal those timing relays we all know and love that are common to most US&S relay timecode systems: 1L, 2L, LP, LB … some things never changed 🙂