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Discussion Starter · #1 ·
This is a response to a request from one of our newer members.

First use of colour light signals: London Underground about 1898

First Overground use: Liverpool Overhead Railway 1920

The principle of three-and four aspect signals was agreed by the Institution of Railway Signal Engineers in 1924. This was rapidly followed by the Southern Railway installing its first four-aspect signals in 1926.

Some companies used 'Searchlight' signals where the same lens and lamp could give the three aspects by filters being moved mechanically in the signal. This was to keep the main aspects as close to the best viewing position for drivers to sight the signals as possible. A second yellow-only aspect was added when four aspects were needed.

Most railways used three or four aspect signals made with a separate lens for each aspect - easier to maintain but slightly more expensive to make. After 1960 searchlight signals were dropped.

The LMS had a relatively short-lived 'Speed' indicating system in the Mirfield area in the early 1930s.

More recent developments include 'flashing' aspects to give the fastest moving trains greater information on the track ahead.

Hope the above helps.
Regards,
John Webb
 

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The most recent development is LED signals, which resemble the old searchlights in having a lens that can display red, yellow or green. The difference is that this is done by a multi-coloured LED cluster rather than mechanical movement of coloured glass. 4-aspect signals have a second lens twice the normal distance above, which can display only yellow.
 

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Discussion Starter · #3 ·
Thanks for the info on LED signals. None of my reference books are that up to date.

Is the multi-LED cluster behind any sort of lens at all? Or are they more like the similar application to traffic lights where they just are behind a plain glass or plastic sheet which keeps the rain out?

Regards,
John Webb
 

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Hi John
You may find this site interesting Dorman Railway signalling Dorman Unipart supply Network Rail with LED main and subsidiary signals for new and also as a direct replacement use.
There is a lens fitted but not Fresnel as per old filament lamps. Short and long range main line LED signals can be obtained.
 

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thx guys,

Well it looks like I can't justify colour signals on my proposed LMS/LNER layout.. sort of new this really but had to check


Be much easier if I modeller later BR steam of course btu not quite the same for me...

I would love working semaphores in N gauge but too much work and no-one does them ready made. Really never understood why no-one has done that. Must be a big market for working semaphores out there...

Cudders
 

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Cudders,

There were parts of both LMS and LNER that had colour lights pre-WW2. I've not done much research because it's not my particular area of interest, but you may find that some urban areas had colour lights, as well as sections of main line - for example the Thirsk/Northallerton area of the East Coast mainline had an early three-aspect semaphore power-operated system replaced by colour lights in the 1930s. On the LMS surburban lines out of Euston colour-light signalling using mostly two-aspect searchlight signals were installed, again in the early 1930s.

So if you model a fictious location on a main line near to an urban area jointly used by LMS/LNER in the 1930s you could choose to install colour light signals. Start off by looking at 'Two Centuries of Railway Signalling' by Kitchenside and Williams. (See topic Sources of Information on Signals in this sub-forum.)
Regards,
John Webb
 

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QUOTE (John Webb @ 5 Jul 2007, 10:48) <{POST_SNAPBACK}>Cudders,

There were parts of both LMS and LNER that had colour lights pre-WW2. I've not done much research because it's not my particular area of interest, but you may find that some urban areas had colour lights, as well as sections of main line - for example the Thirsk/Northallerton area of the East Coast mainline had an early three-aspect semaphore power-operated system replaced by colour lights in the 1930s. On the LMS surburban lines out of Euston colour-light signalling using mostly two-aspect searchlight signals were installed, again in the early 1930s.

So if you model a fictious location on a main line near to an urban area jointly used by LMS/LNER in the 1930s you could choose to install colour light signals. Start off by looking at 'Two Centuries of Railway Signalling' by Kitchenside and Williams. (See topic Sources of Information on Signals in this sub-forum.)
Regards,
John Webb

Hmm yes, Just found some of that info. I always go ficticious so maybe I could do it afterall. The period is anything LNER/LMS so right up to nationalisation. Makes DCC that bit more appealing now


Thx John
 

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I noticed that on the Shrewsbury to Birmingham New Street twin track route that some former twin aspect colour light signals, between stations, have had the top aspect blanked off with flat black sheeting leaving only the lower (formerly red aspect) showing.

I could only see signals on the opposite track which were all showing green aspects but they did look like LED's so I assume that these are bi-colour LED's which can also show a red aspect.

Telford station was devoid of platform starter signals but at other stations (e.g. Wolverhampton) traditional 4 aspects, some with route panels or feathers were in use.

Dorman's have a useful pdf sales brochure giving pictures and details of their LED signal products at:- http://www.dorman.co.uk/Product%20bulletin...ht%20Signal.pdf
 

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All the LED signals that I have seen, both new signals (Nuneaton) and replacement (all sorts of places) maintain the silhuoette of previous signals whether it is 2, 3 or 4 aspect. So a 2 aspect gets one LED cluster with a backboard big enough for two, a 3 aspect gets one LED with a larger backboard for three and a 4 aspect gets 2 LEDs and a four aspect board. I suspect that this is to both quash any questions about the visibility of the LEDs against whatever background and (possibly more the case) to avoid having to do a whole mass of Driver Route Learning for "signals that look different".

A couple of years ago I was amazed to see some brand new semaphore signals with "Health and Safety" (insane) structures. When I asked the reason for the lunacy the reason I was given was that they maintained the image that drivers expected and therefore avoided the cost of Route Learning. This seems crazy when replacement of a semaphore with a colour light signal used to be so simple...

One thing about the LEDs...

From the approach side (In Rear of the signal in real-rail-speak) the LEDs are extremely bright and penetrate weather far better than the old aspects ever did. They are very impressive. ...however! If you are walking down the track (on a safe cess of course) trying to locate a signal [from behind] in the gloom the old aspects cast a pall of light around them in the murk and reflected off of anything like OHLE stanchions. This made it much easier not just to find them but to get an idea of how far away they still were when quiet a long way In Advance (Beyond In New-Speak) of them. The LEDs don't do this at all. If you don't keep a lookout you can find that you have plodded well past a LED or pair of LEDs on the far side of 4 track. This is not fun on a freezing wet night.

There were some very new looking aspects at Lancaster early this year. I will have to dig out my pics to see if they are a different kind of LED or something else.

I'm going nuts learning how to post pics on at present - so if someone would like to volunteer I will e mail them pics of various recent types of aspect and they can post them here. (That way you will get them before Christmas).

Not colour light but related - and I imagine already known here - there was a massive drive to switch the bulk of old style standard 2 or 3 apsect Position Light Signals to LED PL Signals a couple of years ago now.

None of this will help the OP with LMS/LNER but it does cover "colour light history".

 

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QUOTE (John Webb @ 1 Jul 2007, 21:55) <{POST_SNAPBACK}>This is a response to a request from one of our newer members.

First use of colour light signals: London Underground about 1898

John Webb

This is going to be a very inadequate post - but it is about a find I had while researching... I have never seen any reference to it anywhere else or since - I do have a photocopy from the original journal but don't have a clue where in the chaos after two moves in less than two years (admittedly some years ago).

Anyway... The find was...

The LSWR carried out an experiment with a white light signal that, as I recall, was a light effectively inside a vertical half cylinder that was mirrored on the inside. This was surrounded by a full cylinder that could be rotated in the same way that a conventional semaphore arm is rotated - except that the rotation was about a vertical axis instead of the conventional horizontal. Rotation changed the display from a horizontal white bar to a 45 degree white bar - that is the "aspects" mimicked a semaphore arm. I think that a 3rd position was suggested as possible but not used in the experiment. One signal was set up I think between Nine Elms and Vauxhall for a trial period in I think the 1890s. It didn't last long! It was, however, an early attempt at light signalling without arms .

I have never seen any other reference to it... I'm afraid that all I can tell you at present is that it was in the immense pile of stuff I worked my way through at The I Mech E.

A patent or proposed patent about the same time involved fitting the centre line of a semaphore arm with a line of lights.

In some ways it is rather surprising that British signalling took such a single/uniform colour light route and that (apart from MGR train unloading signals) we never went for Baltimore & Ohio (or similar) white light or colour light signals.

Sorry I can't give you a scan of the photocopy... I will try to find it - over the next decade or two,

Maybe someone else knows about the LSWR experiment?
 

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QUOTE (John Webb @ 1 Jul 2007, 21:55) <{POST_SNAPBACK}>Some companies used 'Searchlight' signals where the same lens and lamp could give the three aspects by filters being moved mechanically in the signal. This was to keep the main aspects as close to the best viewing position for drivers to sight the signals as possible. A second yellow-only aspect was added when four aspects were needed.

Regards,
John Webb

Delighted to see this included! My first thoughts were about Searchlight Signals.

I was familiar with the GWR pattern with the small coloured aspects inside the signal head between the lamp and the lens (lenses?) Those were IIRC a lot like a single colour light aspect - possibly rather bigger. Then I stumbled on the Searchlight signal on the present GCR - which has a white lamp and lens behind a conventional external semaphore aspect plate.

Senility now creeps in... Did I once see something similar many years ago at Quainton Road? Was this pattern used by the GCR, Met or both please?

Thanks

B)
 

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QUOTE (John Webb @ 5 Jul 2007, 10:48) <{POST_SNAPBACK}>Cudders,

There were parts of both LMS and LNER that had colour lights pre-WW2. I've not done much research because it's not my particular area of interest, but you may find that some urban areas had colour lights, as well as sections of main line - for example the Thirsk/Northallerton area of the East Coast mainline had an early three-aspect semaphore power-operated system replaced by colour lights in the 1930s. On the LMS surburban lines out of Euston colour-light signalling using mostly two-aspect searchlight signals were installed, again in the early 1930s.

Regards,
John Webb

Sorry to come up with yet another issue... But...

Didn't the LMS system, the LNER system or both have a rather odd arrangement of what for want of a better term I will call "lesser signals/indications" fitted on "side arms" that made the signals look a bit like desert cacti?

I know that I have seen something about those signals somewhere - and I'm pretty sure it wasn't Mirfield - but I don't have a clue where. I only have one picture of an example and that's in a flower bed on ??? Preserved Railway. (Oop North someplace).

Thanks

B)
 

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Mirfield had various signals cranked out to the side, but the Euston-Watford DC lines also had something very similar.
 

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Discussion Starter · #14 ·
QUOTE (Bear 1923 @ 13 May 2011, 20:28) <{POST_SNAPBACK}>Sorry to come up with yet another issue... But...

Didn't the LMS system, the LNER system or both have a rather odd arrangement of what for want of a better term I will call "lesser signals/indications" fitted on "side arms" that made the signals look a bit like desert cacti?

I know that I have seen something about those signals somewhere - and I'm pretty sure it wasn't Mirfield - but I don't have a clue where. I only have one picture of an example and that's in a flower bed on ??? Preserved Railway. (Oop North someplace).

Thanks


The set-up on the Euston-Watford line was another of Bound's experiments (it was about the same time as his Mirfield 'speed signalling' trials) and used additional marker lights before and at main stop signals. These markers were below the main light on stop signals and on the left of the repeater signals sited about a train's length before the main signals. It was, in effect, an approach-controlled calling-on system. There is a detailed description in "Two Centuries of Railway Signalling" by Kitchenside and Williams.

Re the search light signal in a flower-bed, I think that's outside Bolton Abbey station on the Embsay-Bolton Abbey line. They have long-term plans to signal Bolton Abbey with an electro-pneumatic points operating system and searchlight signals - a very distinctive first in preservation when done! There is some information on their website.

Regards,
John
 

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In OO gauge model terms I remember that in the 1960's TRIX made a single aspect colour light signal which had two bulbs in the base and used early fibre optics for the signal post and which was very near to OO scale size. Much better than the equivalent Tri-ang/Hornby twin aspect!

Thanks for all the information to everyone about the change to LED signals my 1975 edition of BR Railway Signalling (by G.M. Kichenside & Alan Williams) from Ian Allan does show the Watford signals in colour schematic form and black & white photos of the Mirfield and Watford actual types.
 
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