Page 1 of 2

British Railway Signalling

Posted: Wed Sep 01, 2004 4:16 pm
by solentary
A simple question from an old fogey.

I was brought up with three-aspect (red, yellow, green) and four-aspect (red, yellow, double-yellow, green) colour lights.

Now I note a newer aspect. It is green with a single yellow above it. What does that signal, please?

Thanks for all the good support here.

David

Posted: Wed Sep 01, 2004 4:30 pm
by Optrex
It's a two-aspect repeater or distant signal, directly replacing the old semaphore distant in some cases.

Simple as that. :)


Mike

Posted: Wed Sep 01, 2004 5:32 pm
by Tomnick
Hang on...green with the yellow above? That's the wrong way round to be a normal repeater/distant!

Do you mean that both the yellow and the green lights are lit at the same time? If so, is it a Japanese BVE signal you've been looking at? If not...I'm as confused as you are!

Posted: Wed Sep 01, 2004 5:46 pm
by Optrex
Ack... quite right. I read what I wanted to read. :)

Sometimes signals can be mounted with the lamps in a different order to normal in places where visibility is a problem. For example, if a normal signal is mounted very close to the ground (as opposed to a shunt signal), then the stop or caution aspect is arranged so it is closer to the driver's eye level.

Could this be it?

Mike

Posted: Wed Sep 01, 2004 5:54 pm
by Tomnick
Could well be - that was my one other thought! I take this:
solentary wrote:Now I note a newer aspect. It is green with a single yellow above it. What does that signal, please?
to mean that the green and yellow are displayed at the same time though - not that these are the arrangement of the lenses. I understand 'aspect' to mean an arrangement of lights that a signal is capable of displaying, not a single lens - i.e. a 4-aspect signal is so-called because it can display R, Y, YY, G, not because it has four lenses! Could well be wrong there though...can anyone confirm or else laugh at me?

(Co-incidentally, does that mean that the 'flashing green' signals north of Peterborough are effectively 5-aspect signals?)

Posted: Wed Sep 01, 2004 6:01 pm
by ianmacmillan
There are also 3 aspect signals with yellow, green, yellow.
They are used coming from a two to a 4 aspect area.

And Optrex is correct. The Stop or caution aspect is always nearest drivers eye level.

Most signals in tunnels have the red aspect at the top because they are usually mounted low for clearance.

Posted: Wed Sep 01, 2004 7:08 pm
by jimbob
There are also (now very few) double 'searchlights' there is one at the london end of platform 3 at colchester, this has two lenses but can display Red, Yellow, Double Yellow & Green. It also can be quite Discerning as you watch it changing as it flickers between the coloured filters.

Posted: Wed Sep 01, 2004 7:17 pm
by Optrex
Searchlights are making a bit of a comback in some areas, again for sighting reasons. The new versions use LED technology - they were detailed in Modern Railways magaine a few issues ago about the WCML upgrade.


Mike

Posted: Wed Sep 01, 2004 8:59 pm
by jimbob
You also get some limited visability areas cause the normal 4 aspect to be horizontal rather than virtacle.

Posted: Wed Sep 01, 2004 9:29 pm
by Tomnick
Excellent stuff - thanks for the info :) . Speaking of ground level signals - I've seen a few of these around, particularly in tunnels. Are there many 2-aspect repeaters at ground level around the network though? I seem to remember one on the Cumbrian Coast somewhere - something to do with high winds on an exposed sea wall section?

Searchlight signals - I've heard a few stories about those! I'm told that they used to (and possible still do?) change from yellow to green - via red! Don't know if it's true, but probably caused a few nasty brown stains if it is... :D .

Posted: Wed Sep 01, 2004 10:34 pm
by solentary
I am now even more confused than before. There are two possibilities emerging for me. One is that this is where a home signal is at clear (green) and the distant signal, on the same post in a short physical headway, is caution (yellow). But that would seem at odds with using th more standard double-yellow.
The second is that I am still using Japanese signals on BVE. One example is signal TN33 on the Ashford to Orpington line on BVE, the second signal past the junction north of Ashford.

I shall, as a precaution, go now to my BVE stuff and download the British version of the signals. I thought I had done that - ages ago - but maybe not! Thanks, as always, friends - and sorry! I see that this FORUM should have been for MSTS stuff. Please forgive me my trespasses!

Posted: Wed Sep 01, 2004 10:52 pm
by solentary
Hi again! I just did the BVE download of British signals. The signal TN 33 on the Ashford to Orpington line still shows a four lens post. The bottom lens is green, the middle two are off and the top one is yellow.

So - what does this mean? Something that I have not come across so far in my railway career.

David

Posted: Thu Sep 02, 2004 6:38 pm
by Tomnick
Oo 'eck...just noticed that we are, most definitely, trespassing! Just to quickly answer (before the bailiffs come round :wink: ), the reason that you haven't come across it, is because it doesn't exist! That's definitely one of the Japanese signal aspects!

Have you definitely installed the British signals to the right folder? I had no problems, but if you've got BVE itself in someplace other than where it wanted to go by default, you might find that the signals are in the wrong folder! The best way to check is probably to look at one of the RelayX.bmp files (found within your main BVE folder) - if these are the familiar 'banner' repeaters, then all should be well! If you see something that looks more like a hump-shunting signal, then you're still using Japanese signals!

Keep us updated anyway! And, if there's anyone here with the right powers, any chance of shunting this over to the BVE Forum? Just to keep us safe from any men with big sticks... :) .

Posted: Thu Sep 02, 2004 8:19 pm
by johndibben
Tomnick wrote:And, if there's anyone here with the right powers, any chance of shunting this over to the BVE Forum? Just to keep us safe from any men with big sticks... :) .
It's very interesting and no real need to move it that I can see.

We're not ogres and only use big sticks on trolls :)

Posted: Thu Sep 02, 2004 8:43 pm
by thenudehamster
Where is this signal? It sounds reminiscent of the former NY Central speed related signalling system (also tried out by the LMS at one time) now fairly standard in the US, which uses siglamps at differing heights to signify different route aspects, often on the same line - it's a peculiar concept and takes some understanding; I'm not sure I get it yet...