Unconventional Signals

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Inversnecky

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How many signals had an unconventional arrangement like the infamous SN109?

Why was SN109 designed like that: seems to have been room for vertical alignment of all four aspects.

Wonder how many of these cases were because of unusual or not to obvious aspects:

 

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zwk500

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No idea how many others are out there, but my understanding is that SN109 was arranged like that because of a bridge or gantry (or combination of multiples of them) restricting viewing at the braking point.
 

edwin_m

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There are quite a few co-actors (duplicate signal on the ground) and a few signals mounted horizontally under platform canopies, both discussed recently on other threads. Birmingham New Street used to have searchlights - for sighting reasons I think, but later replaced by normal signal heads. Nottingham retained a couple of searchlights until resignalling in 2013, due to sighting under the footbridge I believe,which also required co-actors at the other end of the station. I'm not aware of any others like SN109 with the red aspect separate, although I've an idea there were a couple of others elsewhere in the Paddington re-signalling.
 

Snow1964

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Some colour lights installed by Southern railway had small repeaters on the side. Used where signal was against a bridge or tunnel wall and allowed drivers of electric multiple units to draw up virtually level with signal where platform lengths were restricted.

There used to be electo-mechanical banner repeaters under some platform canopies (even in colour light areas), but fibre optic type has replaced these. There were some locations with double banner repeaters above each other, one with a fishtail, again for sighting, not sure if any still exist.

From memory the signals at the exit of Southampton Tunnel are unusual layout, nearer the centre line (so crown of tunnel doesn’t obscure them) with theatre indicators and calling on signals to side. I think could also signal a siding (but that might have gone now). The same gantry has two 4 aspects towards the tunnel as both lines as fully bi-directional as the tunnel section is between 4 track sections.
 
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Annetts key

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There have been various unusual configurations in the past, but such unusual signals are not normally being installed now that LED signals are available.

The reason these were used was normally due to limited sighting.

The modern way is to use a standard LED signal head and have a LED banner signal on approach. LED banner signals are now available that can show a green light instead of a white light if the main signal is showing a green aspect.
 
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30907

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How many signals had an unconventional arrangement like the infamous SN109?

Wonder how many of these cases were because of unusual or not to obvious aspects:

I don't recall comment at the time suggesting a connection, but it was 20 years ago.

Looking at the list, there aren't any obvious locations to have "odd" signals - unless it was the Southampton Tunnel ones.
 

Horizon22

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No idea how many others are out there, but my understanding is that SN109 was arranged like that because of a bridge or gantry (or combination of multiples of them) restricting viewing at the braking point.

Yeah the Ladbroke Grove report goes into great detail about the signal sighting issues (they didn't sight them after key changes), how and why the signal was changed to the "Reverse L" and how the Heathrow Express electrification and bridge gantries caused a cluttered mess, how many SPADs there were in the late 90's in that section, as well as it being unclear which signal was for which line in/out of Paddington.

A quote from the report:

At a re-signalling meeting on 15 April 1994 it was agreed that the signals on gantry 8 should be re-configured so as to take the form of a “reverse L”. It was recognised that this did not comply with the then standard, SSP 4. On 20 May 1994 Mr Colin Bray, Signalling Standards Engineer, wrote to Mr R McCulloch, Signal Engineer, noting that the proposed arrangement of aspects would have the effect of allowing the linespeed to be increased to 70 mph. He recommended that the non-compliance of the signals on gantry 8 should be accepted provided that their operating colleagues accepted that there was “no significant risk of non-reading of the non-standard signals”. He also recommended that the non-compliance with SSP 6 in regard to signal sighting time should be accepted. It was stated in evidence that the re- configuration had been peer reviewed by senior signalmen and “it seemed to be the consensus of those that had contributed that it was probably about the only reasonably practical arrangement that we could arrive at”
 
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Not sure how far into the past the OP wants to cover, but the western end of "old" Manchester Victoria (and Exchange) had some unusual 4-aspect colour lights in a cluster arrangement.

The two yellows were above each other, whilst the red and green aspects were off-set on each side, in a kind of diamond arrangement with a circular backing plate.

I understand these were originally installed in a LMS re-signalling scheme around 1929. Certainly some were still there into the 1960s and some specimens could be found as far west as Ordsall Lane Jn. - though I'm unsure if any lasted right through until the major rebuilding and abolition of Vic West Jn. and Deal Street boxes, or whether BR replaced all these signals with a more standard in-line pattern in later years. It's surprisingly hard to track down images of these signals on the web.

I believe similar 4-aspect clusters were installed for the Southern Railway (also by Westinghouse) in the London Bridge / Charing Cross / Cannon St area in the 1920s.
 

swt_passenger

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Didn’t the recent thread about “Signals Light Order” also cover the reasons for SN109 already?

Isn’t it likely this thread will end up with a huge overlap with this one:
 

Inversnecky

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Not sure how far into the past the OP wants to cover, but the western end of "old" Manchester Victoria (and Exchange) had some unusual 4-aspect colour lights in a cluster arrangement.

I understand these were originally installed in a LMS re-signalling scheme around 1929. Certainly some were still there into the 1960s.

I realise that the semaphore signals familiar to us weren’t fully standardised till the 1930s (eg distant), but I was meaning the topic to include semaphore too, and not be restricted to colour lights.
 
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Skoodle

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TL601 at Sydenham, when it was changed to LED style a couple years ago, now has the No.1 Junction Indicator placed to the left of the actual signal, instead of placed on top of it.
 

Annetts key

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I realise that the semaphore signals familiar to us weren’t fully standardised till the 1930s (eg distant), but I was meaning the topic to include semaphore too, and not be restricted to colour lights.
That opens up various cans of worms, in the past there were lots and lots of unusual semaphore and colour light signals.

Even signals that were both signals and not signals at the same time, like the saint Andrew’s crosses at Bristol Temple Meads station... (picture on this page ). Not part of the signalling system (powered by the station 240V lighting circuits), but drivers were to treat them as stop signals unless routed through the whole platform.
 

Class172

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Worcester Shrub Hill possesses a very unusual example of a full semaphore signal (SH80 if the memory serves correctly) with the appearance of an oversized shunting disk. It is situated half way along platform 1, suspended from the canopy, and is accompanied by a smaller ‘normally proportioned’ calling-on disk beneath it.
 

MadMac

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TL601 at Sydenham, when it was changed to LED style a couple years ago, now has the No.1 Junction Indicator placed to the left of the actual signal, instead of placed on top of it.
There was one like that at Alexandra Parade in Glasgow due to it being under a bridge.
 

Y Ddraig Coch

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Does anywhere else have a signal like Conwy which was only installed due to a local shuttle using the wrong road as far as Conwy before returning to Llandudno Junction. So basically has never shown any other aspect than red and the shuttles it was there to protect stopped 30 years ago?
 

CyrusWuff

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Signals ME353 and ME187R on the approach to Bicester South Junction are two of very few examples of colour light Outer Splitting Distants on the network if that counts.
 

vikingdriver

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London end of Weybridge has a signal like that on the Up Fast if I recall correctly. So the driver could see the two most restrictive aspects, single yellow and of course, danger.
 

The Planner

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Signals ME353 and ME187R on the approach to Bicester South Junction are two of very few examples of colour light Outer Splitting Distants on the network if that counts.
Did the ones at Tilehurst go as part of Reading?
 

JN114

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Did the ones at Tilehurst go as part of Reading?

All the Western region splitting distants are “Inner” examples - IE the signal preceding the junction signal.

Bicester South Jn is the only example I can recall of an outer Splitting Distant.

There are still several “inners” on Western route -

SN212 approaching Ealing Broadway Up Main
SN271 approaching Hayes Down Main
SN312 approaching Stockley Up Relief
T1624 approaching Ruscombe Up Relief
T1759 approaching Tilehurst Down Relief
T1764 approaching Tilehurst Up Main

****

As to L or reverse-L shaped signals, some of the signals on the Heathrow branch are also configured as such, as stacking them vertically they’d be too tall for mounting close to the tunnel walls.
 

30907

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Does anywhere else have a signal like Conwy which was only installed due to a local shuttle using the wrong road as far as Conwy before returning to Llandudno Junction. So basically has never shown any other aspect than red and the shuttles it was there to protect stopped 30 years ago?
Kent House had a permanent red installed in 1967 on the Up Main for the new peak terminators.
 

John Webb

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Does anywhere else have a signal like Conwy which was only installed due to a local shuttle using the wrong road as far as Conwy before returning to Llandudno Junction. So basically has never shown any other aspect than red and the shuttles it was there to protect stopped 30 years ago?
St Albans City Station had a semaphore fixed stop signal at the north end of the up slow (south-bound) platform from 1973 until 1979 which allowed down trains to use a facing crossover from the down slow line to cross over into the up slow line platform from whence they could return towards London either as service trains or ECS. This signal was removed on the start of the new multiple aspect signalling worked by West Hampstead PSB and the introduction of a proper turn-back siding between the two slow lines in December 1979.
 

Fincra5

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TL601 at Sydenham, when it was changed to LED style a couple years ago, now has the No.1 Junction Indicator placed to the left of the actual signal, instead of placed on top of it.
There's a signal (or was - been years since I drove towards London Bridge) on the UP Fast, after Norwood Junction that had Junction Indicators (Postions 1,2,4,5 I think) on the left and right of the Main Signal. We used to call it the "Gromit Signal" download.jpg
 

swt_passenger

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Kingston platform 2 has one - installed to allow ten-car trains (too long for the bay platform) from the Twickenham direction to terminate there
But is a “ fixed red” actually an “unconventional signal” as the thread asks about?

Then how about Brockenhurst, where a fixed red at London end of P4 stops the up direction Lymington shuttle? Maybe it’s not so common, but presumably it conforms to standards?
 

zwk500

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But is a “ fixed red” actually an “unconventional signal” as the thread asks about?

Then how about Brockenhurst, where a fixed red at London end of P4 stops the up direction Lymington shuttle? Maybe it’s not so common, but presumably it conforms to standards?
I agree, a fixed red is a conventional signal because the aspect's exactly where you'd expect to find it. They're also fairly common across the network.
 

pompeyfan

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It’s been a while since I’ve been in a cab in the area but I believe the up signal at Lymington junction on the up main is a splitter, either that or it may just be a splitting Banner Repeater. I forget!
 

Western 52

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Worcester Shrub Hill possesses a very unusual example of a full semaphore signal (SH80 if the memory serves correctly) with the appearance of an oversized shunting disk. It is situated half way along platform 1, suspended from the canopy, and is accompanied by a smaller ‘normally proportioned’ calling-on disk beneath it.
I think that signal is the one known as the "banjo ". It's an amazing survivor!
 

MarkyT

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That opens up various cans of worms, in the past there were lots and lots of unusual semaphore and colour light signals.

Even signals that were both signals and not signals at the same time, like the saint Andrew’s crosses at Bristol Temple Meads station... (picture on this page ). Not part of the signalling system (powered by the station 240V lighting circuits), but drivers were to treat them as stop signals unless routed through the whole platform.
I know the St Andrews crosses were considered the limits of authority for position light movements in the old signalling at Temple Meads. The signals authorising movements towards them were equipped with numeric route indicators, and the appropriate description would illuminate with the correct signal aspect according to whether the near or far platform number was the destination. I realise there were separate exit buttons for the short routes to the crosses, but could a position light also be cleared to the far platform with that already occupied, or was a PL equivalent movement beyond the cross only ever possible under signallers' verbal authority?
 
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