Saturday, April 9, 2022

Union Pacific Automatic Cab Signal Training Videos

 With the fate of UP's Automatic Cab Signal system unclear, I found what appear to be 1980's ACS training videos on Youtube.  The first discusses basic use of the system and the second inadvertent activation in non-cab signal territory. Interesting takeaways is the use of heavy cast iron control and display boxes on board the locomotive as I assume Union Switch and Signal had no capacity to work in plastics or sheet metal 😏


The cab signal "hits" video is interesting as since UP uses a 60hz code carrier, mains current that enters the rails could trigger such an event on any equipped locomotive, anywhere on the system and if the crew isn't on the ball the activation could result in a penalty brake application.

One additional point of note is the similarity of the US&S ACS display with a standard Soviet pattern ALSN cab signal display of the type that appears in this video at about the 14 second mark. about the 14 second mark.


1 comment:

  1. The similarity with ALSN displays could come from the fact that US&S actually did several signal projects in the early Soviet Union. I'm not sure if cab signals were done then, but many colorlight signals in Soviet-influenced areas look eerily similar to R-2s

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