Signalling Logic

[Conductorphil]

I'm currently working on a small, fictional branchline UK layout which I'm really enjoying, however, I have come across a problem and I am not sure what would be the "logical" method.

When coming out of a station in the south, the line splits in two. The track going left rises up and rejoins the mainline (Which crosses over the railway further down) while the other track continues down the branchline to another station.

Most work on the branchline is done independantly, which basically means most work on the branchline stays on the branchline.

There are three signals that I can use to show which direction the train is going when crossing the turnout, either left onto the mainline or right, staying on the branch. The raised signal indicates that a track is a "main" track (While the lower one is a diverting). Which one should be considered the "main" track - the mainline divert or the branchline divert?

Many thanks.

 

[Bill69]

I don't know exactly what your layout configuration is but you could consider using a BR signal 01 which shows both ways as a diversion.

This one.

Cheers,
Bill69

 

[Conductorphil]

Thanks Bill

The route era that I am using is roughly around the 1950's - 60's, so I am using semaphores. There is an option to use a junction semaphore that have both semaphores at the same height so I think I'll go with that.

Many thanks.

 

[itareus]

A lot of signalling practices depended on the originating company, for example the GW had lower quadrant signals whereas the rest had upper quadrant and, even locally, practices varied a lot in the early days.

Generally speaking the higher post and arm denoted the 'main' route and the lower the 'secondary' althought main and secondary had no hard and fast definition!

Have a look here for UK signalling info:

http://www.signalbox.org/signals.shtml

There are also some useful links on that site - Menu item 16.

Regards

Chris

 

[Conductorphil]

A typical signal serving a simple junction has two arms. The right-hand arm applies to the main line (fastest route) and the left-hand arm serves a branch or loop line.

Thanks for the link Itareus. Helped a small amount.

I think in this case I'll use the upper signal as the branchline signal and the lower one as the divert to the mainline, as most work on this route is independant (It's coal based with a coal mine on one side and an offloader at the other)

Many thanks

 

[AntonyVW]

I know this may sound "illogical" but to me the logical answer depends on the traffic. What I mean is - you said that most of the traffic stays on the branchline - so for that traffic the most important route is the branchline. So I personally would give that the priority. but that is just me.

 

[AntonyVW]

I know this may sound "illogical" but to me the logical answer depends on the traffic. What I mean is - you said that most of the traffic stays on the branchline - so for that traffic the most important route is the branchline. So I personally would give that the priority. but that is just me.

 

[itareus]

..I think in this case I'll use the upper signal as the branchline signal and the lower one as the divert to the mainline...

I would do the same myself - and whatever anybody says it's your railway !!

Cheers

 

[colourlight]

In signalling terms the signal at the junction which takes you from the mainline to the branch is considered to be a "branch" signal and would be the lower gantry signal. However, once you are on the branchline it is considered to be the mainline for signalling purposes and all signals that apply to your branchline are mainline signals. So, in answer to your question the signal at your junction that takes you along the branchline is the main signal and the signal that takes you back to the mainline then becomes the branch signal.

 

[nexusdj]

It's all in the name , The branch line being a branch off a mainline should be the lower arm but you need to take into account the diverging speeds of the junction . The higher arm applying to the route with the higher speed . Should both routes be the same speed then a post with both signals set at the same height should be used .

 

[chrisaw]

Whether a line is called the main or branch is imaterial. I'm pretty sure (although I'm sure there will be exceptions) that the comparative height of the signal arms is determined by the line's speed limit, the lower arm being for the slower direction.

Chris.

 

[stovepipe]

A lot of signalling practices depended on the originating company, for example the GW had lower quadrant signals whereas the rest had upper quadrant and, even locally, practices varied a lot in the early days.

That's a common misconception about Lower Quadrant signals. Many other companies used them besides the GWR, the North Eastern Railway and Midland Railway for two.