Signals questions

Hey guys, I just got the BLMA Modern Cantalever Signal Bridge. It has four LED signals (Green, Yellow, Red). I was looking at getting the Logicrail signal animators.

All I want to do is to have the infrared detector that logicrail has, change the signals when a train passes over it.

I have two parallel mainlines where this signal is going. Northbound and Southbound.

Can someone explain how the signals are suppose to work? Like for instance, the top left signal, what is it indicate?

And do I need 4 infrared detectors? For northbound trains, and southbound trains.

And do I need 4 of their circuit boards, or will one of them do what I need?

Thanks for the help!

I’ve worked with Chuck Stancil at LogicRail on some questions I had. Real nice person and I’m sure he would be glad to answer any questions you might have. Phone call or email him. Good choice on the Logic Rail detectors, I’ve got a couple Example:

http://www.youtube.com/user/ClinchValleySD40#p/u/13/r6Aq9oUHtv4

Michael,

BLMA has a video on its web site that illustrates the light combinations.

Check it out:

http://www.blmamodels.com/cgi-bin/webstore/shop.cgi?c=videos/signalbridge.htm&t=main.htm&storeid=1

Rich

Thanks Rich!

I think I have an idea, I did a quick search on signals.

1.) So the top left signal = left main northbound

2.) bottom left signal = left main southbound

3.) Top right signal = right main northbound

4.) Bottom right signal = right main southbound

I tried to call Logicrail, nobody answered, left a message. Waiting to here back from them.

But I think in order to have 4 different infrared detectors, I need the 4 different circuit boards. So I just ordered 4.

Let me know if I’m wrong on this?

OK Chuck from Logicrail just called me. Very nice guy. I indeed need the 4 circuit boards. And he told me where to place the infrared detectors.

I am no signal expert, so I could easily be mistaken.

But, I believe that the two left signals correspond to movements on the inner track, and the two right signals correspond to movements on the outer track.

That modern cantilever signal bridge is showing block signals. The top signal heads, both left and right, indicate the status of the block ahead, and the bottom signal heads, both left and right, indicate the status of the current block.

For example, say the top left signal is red and the bottom left signal is green. That setup indicates that there is a train present in the next block on the inner track and no train present in the current block.

A yellow signal indicates that the block after the next block is occupied, so proceed at reduced speed.

Can someone with more signal expertise confirm this (or correct this)?

Rich

OK I’m going with Rich’s suggestions on the detection placement for the signals.

Unless someone else chimes in?

Sorry, but I don’t think this is correct. To be seen by an engineer, the signals for the northbound track would have to be on the opposite side of the signal bridge from the signal seen by an engineer going south on the northbound track.

Also, unless there is something new going on with signaling, I don’t think the the signal indications on two signals above each other reference the block ahead as well as the block ahead of that. From what I know, the lower signal aspect normally has something to do with a diverging track.

However, take a look at the following website, http://www.lundsten.dk/us_signaling/signalbasics/. It might have some helpful information.

Where I am placing the signal, I actually have a single crossover. So I think what Rich suggested will work for me.

If a train is coming towards me (southbound) on the inside track, and takes the single crossover to the outside track. In this case, when a train approaches going away from me (northbound) on the inside track, the signal will be red, warning that a train is on either the inside track, or taking the crossover.

Also, this place on my layout, the signal bridge can only be seen on one side.

It might not be completely prototypical, but I’ll take some modeler’s choices.

I am very interested in the various methods that can be used to interpret these signals. Apparently, there is no single right answer.

I found this reference on the Internet:

http://model-railroad-hobbyist.com/node/4381

Scroll down the page to find the section titled BLMA Signal Bridge. It contains a message from Craig Martyn of BLMA about how to wire and interpret these signal lights.

As a resource, LogiRail has designed a signal wiring diagram to use the Modern Cantilever Signal Bridge with their product. You can download the file from the BLMA website here:

www.blmamodels.com/documents/BLMA_Bridge_Wiring_4030.pdf

This reference may go a long way, Michael, in helping you decide how to wire and interpret your signal lights.

Rich

Both signals on the left are for the track on the left and both signals on the right are for the track on the right. As displayed in their catalog, the signal is for one direction only. Both tracks for northbound diection or both tracks for southbound direction, depending on which way you face the signal. They are two headed signals.

If you are using route signals they can display diverging or advance indications. If you are using speed signals they can display medium and slow speed signals.

If you want them to display prototypical signals, then you will need to establish 3 blocks beyond the signal, each a train length long. There will have to be detection in each block, so for 2 tracks that’s 6 block detectors. You could probably get buy with 4. Any switches in the area beyond the signal will also have to be interlocked into the circuit so if the switch is lined for a reverse route the signal displays a more restrictive signal and if it is lined against a route the signal will display stop.