Looking at a signal tower over a double track on the NS Danville district in Virginia, one side displays stop for track 1 and approach (yellow over red) over track 2, the other side displays clear (green over red) for both tracks. Does this mean theres a train coming soon? No other markings on signal tower. Thanks for the help and information.
I'm not at all sure, but I see various indications on NS and it may have to do with Automatic Block Signaling vs Centralized Traffic Control? NS's line between Columbia, SC and Charlotte, NC sees perhaps six trains a day, is ABS and most times the signals are green. It doesn't indicate a train is coming. NS's mainline between Charlotte and Spartanburg is busier and the signals there are normally yellow over red until the Dispatcher sets up a route and they change to green. On the mainline in this area, green does indicate a train is coming. As you hang around trackside and perhaps carry a scanner, you'll figure it all out and be clairvoyant in regard to train arrivals.
Another signal variation is the always-irritating approach lit signal, which stays dark until train time. The former SAL main through South Carolina (and elsewhere?) remains approach lit.
Thanks for the help! I think you're right about that signal being an ABS, because I parked about 11 miles up from it and a bit later a train came up northbound on the track that had the stop signal for southbound. There's quite a learning curve to all this because I travel a lot due to my job (Trucker) and everywhere I go it seems the rules are a bit different. Ah well that's all just part of the fun.
Good point. Number plates (often the approximate MP) usually indicate a "permissive" signal, while absolute signals lack number plates.
You're right! I'm a signal fan and yet I'm still baffled by what I see sometimes. I took this shot a few years ago of these NS absolute signals and noticed that the backgrounds are trimmed off at the bottom. I'm not sure what this means. Perhaps it's an extra visual indication, adding a margin of notification that these are absolute signals that cannot be passed if at stop indication? Maybe Jovet can help me with this.