Color Light Signalling query

[Meiriongwril]

Anyone know when color light signals started being used on US railroads generally? I want to have a multi-era SP layout (I know SP held on to semaphores for a long time in many areas). Would color lights be out of place in an 1960s SP layout??

 

[60103]

I think colour lights were coming in before WW2. I know Canadian Pacific and Canadian National had them during the 50s.
I think replacement was done on the basis of expediency. If a line were resignalled for higher speed that required moving the signals, colour lights might replace the semaphores, but a single signal destroyed in an accident would be replaced with the same. (A few accidents were blamed on mixing two types of signals).

 

[Greg Elems]

SP was installing single lens search light signals around WWII. Other railroads, such as Santa Fe and Western Pacific fallowed suite around the same time. Main lines using search light signals in California included the Central Valley and Coast route south. North depended on which line and how far. Going east over Donner single lens search light signals were used in ABS territory during the late 50's onward. The early 80's saw the tri-colored signals introduced. Some semaphores still exist on ex-SP lines in Oregon, IIRC. So to answer your question, it will depend on the area and traffic density but SP's classic search light signal is not out of place for many mainlines during the 1960's. If you would like some pictures of old SP signals I can e mail some to you. Also RMC had drawings in HO of the SP standard signal.

Greg Elems

 

[Meiriongwril]

Many thanks Greg - I'd appreciate a few pictures. I'm wondering whether any of the new Atlas N color light models would be possible, so pictures to make a comparison would be very helpful