Signals - Present-Day Semaphore, Lights and Repeaters

[Michael Hodgson]

15 hours ago, melmerby said:

Why leave the distant dark when the UQ is on?

Surely if it is a distant it would be logical to just duplicate what the equivalent semaphore would show?

That's what the GWR implemented when they first put colour light into the Paddington area.  However when you need to to display a stop aspect, the distant is providing irrelevant information by teling you about the signal in advance - and we have to slot it to avoid giving a contradictory message.  Much better for it not to say anything.

[melmerby]

2 hours ago, Michael Hodgson said:

That's what the GWR implemented when they first put colour light into the Paddington area

They were treated effectively as just semaphores without arms and displayed the same aspects, with the moving part (the coloured lens) inside the casing.

 

Now if they had bit the bullet and gone for three aspects instead of two, they could've had speed based signalling. 👍

They were after all standard US signal heads.

[4069]

On 15/05/2023 at 19:08, The Stationmaster said:

Not an exact replacement by any means as that line was originally the Up Goods with a substantial number of connections from the yard plus a facing connection. to the Up Main.  The nearest signal to that site was probably an ordinary straight post signal with a 3ft arm and maybe at one time had a Goods 'ring' on the arm - and no lower arm distant for Banbury South.

I think that signal replaced the disc which can be seen (partly) covered up here. The one alongside was a direct semaphore replacement. Here they are when new, January 1980:

 

Apologies for the poor quality of the picture, but at least it was taken from a genuine GWR vehicle:

Edited May 16, 2023 by 4069

[eastglosmog]

On 15/05/2023 at 17:37, melmerby said:

Is it normal to remove the green spectacle, when a distant is converted to fixed as this one obviously is ?(no pull off wire)

If you look at the Worcester Shrub Hill north end signals  I showed a photograph of on p1 of this thread, you will see that the entire spectacle plate has been removed from both fixed distants and there is just a lamp.

[melmerby]

18 minutes ago, eastglosmog said:

If you look at the Worcester Shrub Hill north end signals  I showed a photograph of on p1 of this thread, you will see that the entire spectacle plate has been removed from both fixed distants and there is just a lamp.

That is the normal way of providing a fixed distant

I commented because the one pictured had originally been an operating signal that had become fixed by removing the operating wire and green spectacle.

[The Stationmaster]

On 16/05/2023 at 14:45, Michael Hodgson said:

That's what the GWR implemented when they first put colour light into the Paddington area.  However when you need to to display a stop aspect, the distant is providing irrelevant information by teling you about the signal in advance - and we have to slot it to avoid giving a contradictory message.  Much better for it not to say anything.

 

23 hours ago, melmerby said:

They were treated effectively as just semaphores without arms and displayed the same aspects, with the moving part (the coloured lens) inside the casing.

 

Now if they had bit the bullet and gone for three aspects instead of two, they could've had speed based signalling. 👍

They were after all standard US signal heads.

A bit of yes and no in there.  The GWR installations at addington, Bristol TM and Cardiff, as Melmerby has siad, exactly replicated teh aspec ts of semaphore signals and the 'lower arm distants' were alight at all times.  II think Michael might have confused them with colour light 'distant' repeaters mounted below semaphore stop signals as was at one time required at sen mapg hore to colour light signalled transitions - those only illuminated when teh stop arm was cleared.

 

As far as 3 aspect signals are concerned the earliet clour light signal at Paddington, which replaced the well known 3 position semaphore on the Down Main was a 3 lens 3 aspect signal R/Y/G colour light signal 

 

The Engine & Carriage Lines between Old Oak Common and Paddington were also equipped with 3 aspect signals plus an automatic Calling On subsidiary (originally a miniature green).  These signals probably predated the main scheme at Paddington and what gradually spread, using the same semaphore style' aspects,  as far as Southall.  and the E&C Lines signals included some of the most original colour light signals I have ever seen.  Even into the early 1960s there were still examples of them with timber posts and standard GWR finials complete with cast iron  vertically arranged number plates mounted on the front of the post while others were mounted on newer, very simple, tubular steel posts.

 

These signals almost certainly post-dated upper quadrant 3 position semaphores on the GWR but seem to have been around before the main 1930s GWR power signalling schemes.  So with plenty experience of 3 aspect signals, including automatic 3 position UQ semaphores, I have often wondered why the company steered away from them to simply replicating 2 position semaphore signal aspects?

[62613]

23 hours ago, melmerby said:

They were treated effectively as just semaphores without arms and displayed the same aspects, with the moving part (the coloured lens) inside the casing.

 

Now if they had bit the bullet and gone for three aspects instead of two, they could've had speed based signalling. 👍

They were after all standard US signal heads.

There were a couple of semaphore home/3 - aspect YGY colour light signals on the same post, in the vicinity of Philips park Junction, on the line from Stalybridge to to Miles Platting. This was before the whole area was rationalised and resignalled in the 1990s. I think they were 3 - aspect because of the closeness of the Philips Park Junctions to Miles Platting, so that with the semaphore home off and a green aspect, you were clear right the way through; double yellow meant clear to MP, and single yellow to Philips Park. That's only a guess!

 

On the westbound approach to Stalybridge, before the tunnel, there was another 3 - aspect YGY signal which I suppose was acting as a distant (there was a signal with a theatre - type route indicator on the exit from the tunnel, in the same direction). That went in the previous resignalling, replaced by a 4 - aspect with a feather

[The Stationmaster]

1 hour ago, eastglosmog said:

If you look at the Worcester Shrub Hill north end signals  I showed a photograph of on p1 of this thread, you will see that the entire spectacle plate has been removed from both fixed distants and there is just a lamp.

That was how the Western did it.  The spectacle plate hadn't been removed for the simple reason that there had never been one in the first place.  The arm was bolted either direct to the post in the case of signals with a timber post or to a bracket which attached it to the post in the case of signals with tubular steel posts.   The lamp case was fixed to the other side of the post in the normal way.

 

This arrangement was clearly adopted fairly early on as there are photos of it taken in the 1920s plus an example of a 5 ft arm photographed with such an arrangement.  On our local branch there was a lattice post (GWR lattice that is) distant signal with exactly the same arrangement until it was replaced by a colour light fixed distant in 1961.

[The Stationmaster]

Colour light signalling in Britain seem to have first appeared in tunnels on some London underground railways.  The signals were 2 aspect and basically consisted of a spectacle plate moving vertically in front of the light source and were power operated. Some had oil lamps while some were electrically lit

 

Daylight colour light signals - as they were originally called because the light was powerful enough to be seen in daylight - first appeared in Britain in 1920 on the Liverpool Overhead Railway.  These were two lens 2 aspect signals showing either red or green.  There were no distant or repeater signals for the stop signals most of which worked automatically.  

By the second half of the 1920s the Southern railway was installing 4 aspect colour lights in the London area on its South eastern section.

 

Notwithstanding these early advances there was still room for something a bit different and the most interesting of these was the mechanically worked colour light signal.  These seem ti have originated on the LNER and were basically a conversion of an existing semaphore signal by removing the arm, providing a backplate to help viewing and, of course, providing a poweful electric lamp.  these appeared at various places on the Southern Section of the ECML although many (all?) were later replaced by ordinary colour light signals.

 

What the phot below shows is a recreated version, probably incorporating some original components which is to be g found on the preserved section of the old GCR route.  So a 21st century photo of a very  20th century way of creating a colour light signals at minimal cost.

 

 

 

 

[Michael Hodgson]

37 minutes ago, The Stationmaster said:

What the phot below shows is a recreated version, probably incorporating some original components which is to be g found on the preserved section of the old GCR route.  So a 21st century photo of a very  20th century way of creating a colour light signals at minimal cost.

Installed by LNERGE of this parish.

[St Enodoc]

8 hours ago, Michael Hodgson said:

Installed by LNERGE of this parish.

@LNERGE must know my old mate Graham Bannister, then.

[eastglosmog]

A couple of photographs of the signal for bi-directional running on the up line at Charlbury station on the OWW.  I have never seen it green - will have to go down and have look next time there are engineering works. 

Bi-directional running is on the up line only, so when a few years ago an HST bound for London failed in the station, there was no way past it.

[Michael Hodgson]

6 hours ago, St Enodoc said:

@LNERGE must know my old mate Graham Bannister, then.

They've known each other for years. 

Graham does a fantastic job on the GC

[melmerby]

3 hours ago, eastglosmog said:

A couple of photographs of the signal for bi-directional running on the up line at Charlbury station on the OWW.  I have never seen it green - will have to go down and have look next time there are engineering works. 

Bi-directional running is on the up line only, so when a few years ago an HST bound for London failed in the station, there was no way past it.

That seems to be the only signal in that direction for 15miles with a crossover at Moreton in Marsh to regain the normal running line, or carry on , using MM38  for another 15miles where it becomes single track at Evesham.

[2251]

Is AW 2409 capable of showing a proceed aspect, is it is really just a limit of shunt indicator?

[The Stationmaster]

14 minutes ago, 2251 said:

Is AW 2409 capable of showing a proceed aspect, is it is really just a limit of shunt indicator?

Not Limit Of Shunt but possibly a Fixed Red to allow a train to be signalled across to the Up to reverse.

[melmerby]

36 minutes ago, The Stationmaster said:

Not Limit Of Shunt but possibly a Fixed Red to allow a train to be signalled across to the Up to reverse.

There isn't a crossover beyond that signal which is at the Worcester end of Charlbury station, on the up line, reading towards Worcester.

The single from Oxford becomes double at Charlbury Jn to the East of Charlbury station. The next trailing crossover is at Moreton in Marsh, 15 miles west of there.

[Mike_Walker]

I think AW2409 is a fixed red but I'm away from my records at the moment.  I'll confirm tomorrow.

[eastglosmog]

When the Cotswold line was redoubled in 2011, the public information was that bi-directional running would be available on the up line.  The reason was so that any required maintenance works on the down line could begin earlier at night with the last train to Moreton traveling on the up line if required.

I can see no particular point in it being a limit of shunt signal.  Why would a down train need to go into the up platform? There are no terminating trains at Charlbury and as Melmerby points out, the nearest crossover is at Moreton.  The timetable is set up so that trains generally cross at Charlbury or a few miles to the east, dictated by the single line to the west.  Main exception is the last pair of trains, which pass north of Moreton - there is enough time in the timetable for the last down train to reach Moreton before the last up train does.

[Mike_Walker]

Having looked it up, I can confirm AW2409 is a fixed red.  It provides a facility to reverse a train from Oxford in times of disruption by routing it into the Up platform.  There is no facility to depart towards Oxford from the Down platform.  The Down direction signal approaching Charlbury, AW2407, has a standard theatre indicator which remains dark if the train is continuing on the Down line but displays U if it is to cross the the Up line. 

 

There is no bi-directional signalling anywhere along the Cotswold Line.

[melmerby]

I'm confused

6 hours ago, Mike_Walker said:

It provides a facility to reverse a train from Oxford in times of disruption by routing it into the Up platform. 

What does that mean?

A train from Oxford goes into the up platform, then what?

[Mike_Walker]

The driver changes ends and it goes back to Oxford.  Simples...

[The Stationmaster]

48 minutes ago, melmerby said:

I'm confused

What does that mean?

A train from Oxford goes into the up platform, then what?

As explained by Mike Walker.  In signalling terms it clearly isn't a Limit if Shunt signal (which is a position light showing two horizaontally arrange small red lights) .    So, as I hinted would be the case, it is a fixed red - that means a running route can be set towards it from another signal and it could be for a passenger train if needed.

 

The big advantage of fixed reds - instead of STOP boards or position light, or Limit of Shunt signals is that it has the ability to set a main route towards it.  That is why I specified the use of fixed reds on the freight lines west of Southall  station for movements which would enter them in the ;'wring' direction.  But in that case my requirement was to get freights off the Main or Relief Lines more quickly (in preparation for the increased passenger train frequency which came with the opening of HEX).

 

Fixed reds have been around for many years although they've never been particularly common but they have definitely become more common with colour light signalling schemes of more recent years (e.g. 1656  at the east end of Kennet Bridge Loop at Reading for an Up direction movement into the loop.  I think there is also one at Kemble fulfilling the same function as the one at Charlbury)  

 

But there were a few semaphore examples including on the WR - there was one created at West Drayton in, I think, the late '60s at West Drayton which had previously been a worked signal.  There was also a query many years ago  in one of the model railway magazines about one on the LMR Watford - St Albans branch.   Very useful things when used appropriately.

[melmerby]

OK

So we saying a train has left Oxford for Worcester but before it gets to Charlbury a problem has be identified further on needing to stop the train.

Train is therefore sent into the up platform and when ready it can now be signalled back to Oxford, which it couldn't do if it was on the down line.

 

Further on~:
What is Evesham 2453 used for?

It's similarly placed facing Worcester at the west end of the up platform at Evesham.

However it must have more than just a red aspect, else it could never be used for anything.☹️

[phil_sutters]

An assortment of signals at Dover & Ashford (currently not) International.