Signals Question

[DC Railfanner]

What is the use of having single red lights at the very bottom of a set of signals. Being a CSX fan, this has always confused me as they don't have them. Thanks!

Example: http://www.railfanguides.us/sc/blacksburg/groverall.jpg

[Wayside]

What is the use of having single red lights at the very bottom of a set of signals. Being a CSX fan, this has always confused me as they don't have them. Thanks!

Example: http://www.railfanguides.us/sc/blacksburg/groverall.jpg

The extra signal head is there to allow for more aspects to be displayed at the location in question, such as a restricting, which is two reds over a bottom yellow.

But now that I actually click through to your link, I see you are asking something else. The signals you show are actually able to only have two lights burning at a time. The top three are red/yellow/green lights. The picture is actually of a location where it appears the signalmen are taking down the the two signals and their supporting signal bridge after having installed the two alongside the tracks.

[DC Railfanner]

What is the use of having single red lights at the very bottom of a set of signals. Being a CSX fan, this has always confused me as they don't have them. Thanks!

Example: http://www.railfanguides.us/sc/blacksburg/groverall.jpg

The extra signal head is there to allow for more aspects to be displayed at the location in question, such as a restricting, which is two reds over a bottom yellow.

But now that I actually click through to your link, I see you are asking something else. The signals you show are actually able to only have two lights burning at a time. The top three are red/yellow/green lights. The picture is actually of a location where it appears the signalmen are taking down the the two signals and their supporting signal bridge after having installed the two alongside the tracks.

I know that the signals are undergoing replacement. What I was confused about was the bottom head on all signals pictures only has the ability to display a red. Therefore, to my knowledge, the only aspects that can be displayed are clear, approach, or stop (there may be more, I'm not an expert on NS aspects) whereas if a head that could only display a red was placed on top it would create medium/limited (diverging on NS) aspects (ex: diverging clear). I was wondering what role a head with a single red on the very bottom plays.

*EDIT: I FOUND OUT THAT THE ALWAYS RED ON THE BOTTOM SIGNALS THAT A MAINLINE ROUTING CAN BE TAKEN OVER THE TURNOUT. BOTH TRACKS HAVE THIS IN THE IMAGE BECAUSE THE SWITCH PAST THE SIGNAL IS A "Y" SWITCH, NOT A STANDARD TURNOUT USED IN A SIDING.

[Wayside]

okay yup

NS signals:
http://signals.jovet.net/rules/NS%20Signal%20Rules.pdf

[bostontrainguy]

Haven't seen signals placed like this before. Anyone have any idea of what's up with this? It's on CSX's S Line in Florida.

Obviously a train in the right track would block the signal for trains on the left track. Doesn't make sense to me.