I had some time to watch the action on the CSX A&WP Sub in Newnan Georgia today, and caught about six trains, not too bad. But after a few passed, I noticed something that seemed odd to me. A quarter mile south of me is a diamond where NS crosses the single CSX track, and two double head interlock signals (probably messed up the terminology) on the CSX line that face outward from the diamond. I noticed both signals were displaying an approach signal, yellow over red. Until now I had believed that if one signal displayed approach, then the opposing signal should display stop. Why would these signals display approach in both directions? The signals have been like this for several hours. Any help or info is greatly appreciated!!!
I shouldn't answer because I'm not sure, but I see this same indication on NS's mainline through Spartanburg, SC when nothing is happening. When a train is expected, the signal aspects change accordingly. I think it's an Approach indication. This page may be of interest to you: http://signals.jovet.net/rules/CSX Signal Rules.pdf
Yeah, after watching it for a bit, I think I have it figured out. The signals default to yellow over red (presumably approach) and flip to high green when a train comes through, then red while train is passing. After train passes, they change to restrict (red over white) until I'm guessing the train has cleared the block, at which point they change back to the default approach signal. They're protecting a diamond and not a block so it would make sense. Thank you for that link by the way!
That is a bit weird. But it sounds like a strange automatic interlocking. The first train to get close enough gets access to the diamond. Why the signals aren't Stop all the time, though, is just odd to me!
