What is this ground shunt signal for?

[Rover]

Hi, could anyone explain the significance of the ground shunt signal on the left hand side of this photograph at Orpington? In particular why a yellow band?
thanks
Kev

 

[Harsig]

Hi, could anyone explain the significance of the ground shunt signal on the left hand side of this photograph at Orpington? In particular why a yellow band?
thanks
Kev

This page should answer your questions about yellow shunt signals:

http://www.railsigns.uk/sect3page3/sect3page3.html

In particular the following extract from the rule book, that appears on the web page, sums it up quite well:

"Shunting signals showing a yellow arm or light may be passed, without being cleared, for movements in a direction for which the signal, when cleared, does not apply."

 

[Rover]

Thanks for that and a very interesting website.

 

[John Webb]

Slightly earlier version we have on display at St Albans South:

The SR, with electricity available, tended to use floodlights rather than the more usual lamps as seen on the left, although we've fitted our ground discs with LED bulbs rather than oil lamps for convenience and greater visibility in daylight!

 

[30907]

Thanks for that and a very interesting website.

In this case, the permitted move is into the headcount or even headshunt (used for berthing) where the 4EPB is sat - apologies if that's obvious.

Edit: autocorrect corrected

Slightly earlier version we have on display at St Albans South:
View attachment 80652The SR, with electricity available, tended to use floodlights rather than the more usual lamps as seen on the left, although we've fitted our ground discs with LED bulbs rather than oil lamps for convenience and greater visibility in daylight!

A pure SR half-moon design, rather than the BR full disc at Orpington.

 

[pdeaves]

I remember being told, slightly tongue in cheek, that a horizontal bar means 'stop, or don't'. As others have said, it depends on the lie of the points and where you are supposed to go.

 

[Rover]

In this case, the permitted move is into the headcount (used for berthing) where the 4EPB is sat - apologies if that's obvious.

No it wasn't obvious to me and it helps me understand the reason for the signal.
Were these signals specific to a region or were they in general use? I don't recall seeing one before but probably have.

 

[Belperpete]

No it wasn't obvious to me and it helps me understand the reason for the signal.
Were these signals specific to a region or were they in general use? I don't recall seeing one before but probably have.

In general use, although not very prolific. I suspect that some regions favoured them more than others, the Southern used them a fair bit, the Western not so much (although I seem to recall a yellow ground-position-light at Old Oak), don't recall ever seeing an example on the LM.

I once came across a fixed yellow shunt, at Poole, I think. The crossover had been recovered, but for some reason they kept the yellow disc, which was fixed as it never needed clearing!

 

[Belperpete]

The big problem with yellow discs is the potential for the signalman to reverse the points just as a train is passing the yellow disc "on". Yellow discs are not supposed to be used on new signalling schemes.

 

[edwin_m]

No it wasn't obvious to me and it helps me understand the reason for the signal.
Were these signals specific to a region or were they in general use? I don't recall seeing one before but probably have.

Yellow shunts were in use over the whole network as far as I'm aware, though the form of the signal itself would follow the local practice of the time and region it was installed in. There were even colour-light versions, like the standard three-lens shunting signal with two white lights but with a yellow instead of the red. I believe some were even converted to the current standard with a bi-colour lens so they showed two yellows at an angle or two whites horizontally, though I don't recall ever seeing one.

More modern installations tend to have two of the standard red-white shunting signals "back to back" but arranged so both can be cleared for shunting to and fro with the points normal. For a move to or from the main line the signaler would put both back to danger then set the appropriate route that would reverse the points. This was certainly the practice in the late 1980s when I had closer involvement with signaling.

don't recall ever seeing an example on the LM.

I found one at Bloxwich in around 2006, facing right onto the level crossing. It would have gone with the Chase Line re-signaling. The link below shows it to be yellow and white, but yellow and black was more common as easier to see.

https://www.expressandstar.com/resizer/MTqSsvvfUiEobzaneTH87hymo-w=/990x0/filters:quality(100)/arc-anglerfish-arc2-prod-expressandstar-mna.s3.amazonaws.com/public/WADS7RRUQRBBNKLBQXD733H77Q

 

[Belperpete]

I found one at Bloxwich in around 2006, facing right onto the level crossing. It would have gone with the Chase Line re-signaling. The link below shows it to be yellow and white, but yellow and black was more common as easier to see.

https://www.expressandstar.com/resizer/MTqSsvvfUiEobzaneTH87hymo-w=/990x0/filters:quality(100)/arc-anglerfish-arc2-prod-expressandstar-mna.s3.amazonaws.com/public/WADS7RRUQRBBNKLBQXD733H77Q

Wow, that is a weird place to put a signal. I suppose it could not be put on the approach to the crossing, because otherwise a driver could pass it "on" and over the open crossing. But that means there must have been another signal, on the approach to the crossing, reading up to the yellow shunt.

The only yellow and black shunts that I can recall were the floodlit ones. I suspect glare from the floodlight made it hard to tell the yellow and white apart at night. Shunts with the yellow and green oil lights wouldn't have the same problem, as the driver would be looking at the oil lights not the disc at night. In my experience, yellow and black shunts tended to be the electrically-operated ones, while traditional mechanically-operated ones tended to be yellow and white.

 

[Bald Rick]

Slightly earlier version we have on display at St Albans South:
View attachment 80652
The SR, with electricity available, tended to use floodlights rather than the more usual lamps as seen on the left, although we've fitted our ground discs with LED bulbs rather than oil lamps for convenience and greater visibility in daylight!

Beautifully restored!

 

[30907]

In my experience, yellow and black shunts tended to be the electrically-operated ones, while traditional mechanically-operated ones tended to be yellow and white.

That makes sense, and ties with my memories.
Slightly OT: a real rarity (I remember being startled) was a full-size yellow semaphore running signal. It was at the exit from Brockenhurst down sidings, and beyond Brockenhurst B down starter (hence needing a running signal). Not sure what the history is, but a look at the box diagram shows the exit crossover was worked from a ground frame, so it may have been a later addition.

https://www.flickr.com/photos/77350329@N07/49937670192
(keen eyes will notice there is a yellow disc on the same line nearer the station.)

 

[John Webb]

Beautifully restored!

Thanks - and it works off our MR ground frame - which is an interesting mix!

EDIT: additional info - thanks to Chief Planner's post below for a reminder of where it was from and for getting it for us.

 

[ChiefPlanner]

In general use, although not very prolific. I suspect that some regions favoured them more than others, the Southern used them a fair bit, the Western not so much (although I seem to recall a yellow ground-position-light at Old Oak), don't recall ever seeing an example on the LM.

There was one at Watford North when the CCD was extant.It was carefully disconnected one Sat am when the S+C was taken out , with a view to using it for training at the school.

In the 30 mins from the disconnection , and before a Traction Inspector could collect , - said disc was stolen. They are quite rare. (hence the keeness to have the ex Petersfield disc saved and restored)

 

[Belperpete]

That makes sense, and ties with my memories.
Slightly OT: a real rarity (I remember being startled) was a full-size yellow semaphore running signal. It was at the exit from Brockenhurst down sidings, and beyond Brockenhurst B down starter (hence needing a running signal). Not sure what the history is, but a look at the box diagram shows the exit crossover was worked from a ground frame, so it may have been a later addition.

https://www.flickr.com/photos/77350329@N07/49937670192

Wow, that is a rarity. Brings home, however, that shunt signals were originally just miniature semaphores.
A shunt disc is basically just a miniature red (or yellow) semaphore arm on a white background for ease of visibility.

 

[Belperpete]

In general use, although not very prolific. I suspect that some regions favoured them more than others, the Southern used them a fair bit, the Western not so much (although I seem to recall a yellow ground-position-light at Old Oak), don't recall ever seeing an example on the LM.

There was one at Watford North when the CCD was extant.It was carefully disconnected one Sat am when the S+C was taken out , with a view to using it for training at the school.

In the 30 mins from the disconnection , and before a Traction Inspector could collect , - said disc was stolen. They are quite rare. (hence the keeness to have the ex Petersfield disc saved and restored)

I was half expecting my comment about not having seen any on the LM to produce a flood of replies listing places. That yours is only the second, suggests that they were very rare on the LM.

Coincidentally, there was a yellow/white shunt disc up for sale on eBay only a week or two ago, in quite good condition, for only £60 if I recall correctly. Was tempted, but I have too much junk in the loft already.

 

[Ashley Hill]

Off the top of my head in my area yellow position light versions exist at Keyham,Exmouth Jct,Bridgewater and Kingsland Road (Bristol). No doubt there are others. Yeovil Jct used to have 2 WR disc versions with black and yellow faces but were replaced with standard red position lights upon resignalling. There are also two yellow discs at Staverton on the SDR controlled by Bishops Bridge box.

 

[edwin_m]

I seem to recall seeing a photo somewhere of a yellow semaphore arm at the exit from the aluminium smelter sidings at Burntisland - probably one of the smaller type used (when coloured red) for entry into loops and sidings. If I could remember the name of the box there I might be able to search it!

 

[High Dyke]

Nene Valley Railway have one on the Civils' Siding, just east of Wansford station; though I understand it's now out of use.

 

[ChiefPlanner]

Wow, that is a rarity. Brings home, however, that shunt signals were originally just miniature semaphores.
A shunt disc is basically just a miniature red (or yellow) semaphore arm on a white background for ease of visibility.

The 2 electrified turnback sidings at Harrow and Wealdstone (No 2) were fitted with 2 LNW semaphore armed shunt signals for departing moves - they survived until resignalling in about 1988 - I really hope they went to a good and safe home. They must have been of 1910 - 1917 vintage when the lines were installed.

 

[4069]

The 2 electrified turnback sidings at Harrow and Wealdstone (No 2) were fitted with 2 LNW semaphore armed shunt signals for departing moves - they survived until resignalling in about 1988 - I really hope they went to a good and safe home. They must have been of 1910 - 1917 vintage when the lines were installed.

Yet the signal to go into those sidings was of Midland Railway design. Maybe it was all that was available when a replacement was needed in a hurry!

 

[alxndr]

Yellow shunts were in use over the whole network as far as I'm aware, though the form of the signal itself would follow the local practice of the time and region it was installed in. There were even colour-light versions, like the standard three-lens shunting signal with two white lights but with a yellow instead of the red. I believe some were even converted to the current standard with a bi-colour lens so they showed two yellows at an angle or two whites horizontally, though I don't recall ever seeing one.

There is an example of one at Thingley Junction on this page (second from bottom): http://www.railsigns.uk/photos/p_shuntsig2/p_shuntsig2.html

It is one of two that I can think of, both of which are controlled by way of a groundframe. Presumably, the thinking is that it's less likely someone would accidentally move the points while a train is traversing them if they're within sight of the thing.

 

[ChiefPlanner]

Yet the signal to go into those sidings was of Midland Railway design. Maybe it was all that was available when a replacement was needed in a hurry!

Possibly to do with the catastrophic accident in October 1952 where some of the down Manchester /Liverpool ended up on the DC lines. (OT a bit)

 

[edwin_m]

There is an example of one at Thingley Junction on this page (second from bottom): http://www.railsigns.uk/photos/p_shuntsig2/p_shuntsig2.html

It is one of two that I can think of, both of which are controlled by way of a groundframe. Presumably, the thinking is that it's less likely someone would accidentally move the points while a train is traversing them if they're within sight of the thing.

Quite unusual to have signals controlled by a ground frame, as hand signals are usually considered sufficient. Is there a particular problem here with sightlines between the GF operator and the driver?

 

[alxndr]

Quite unusual to have signals controlled by a ground frame, as hand signals are usually considered sufficient. Is there a particular problem here with sightlines between the GF operator and the driver?

Perhaps some sloppy wording on my part, the slot for the signal is controlled from the groundframe, rather than the groundframe operator having sole control over the signal.

 

[edwin_m]

Perhaps some sloppy wording on my part, the slot for the signal is controlled from the groundframe, rather than the groundframe operator having sole control over the signal.

To be honest I'm now even more confused, wondering what the situation is that requires a slot on a yellow shunt from a ground frame.

 

[alxndr]

To be honest I'm now even more confused, wondering what the situation is that requires a slot on a yellow shunt from a ground frame.

I can't say I've ever put much thought into it, every groundframe I know has slots so I saw it as the norm. I can only assume it's so that the signal doesn't display white lights until both the signaller says "I'm happy for a train to enter the main line" and the groundframe operator says "I'm happy for the train to leave my yard/siding etc".

 

[John Webb]

There is an example of one at Thingley Junction on this page (second from bottom): http://www.railsigns.uk/photos/p_shuntsig2/p_shuntsig2.html

It is one of two that I can think of, both of which are controlled by way of a groundframe. Presumably, the thinking is that it's less likely someone would accidentally move the points while a train is traversing them if they're within sight of the thing.

Quite unusual to have signals controlled by a ground frame, as hand signals are usually considered sufficient. Is there a particular problem here with sightlines between the GF operator and the driver?

A careful look at the railsigns photo seems to indicate there was once mechanical rodding about (line of now empty 'stools' for holding the rodding rollers going away from the camera) but that the point is now probably electrically operated. Don't know the area at all, but has there been some resignalling in recent years which may have removed the ground frame?

 

[alxndr]

A careful look at the railsigns photo seems to indicate there was once mechanical rodding about (line of now empty 'stools' for holding the rodding rollers going away from the camera) but that the point is now probably electrically operated. Don't know the area at all, but has there been some resignalling in recent years which may have removed the ground frame?

There was a mechanical groundframe but it is now electrically operated. I'm not sure when it was converted as I didn't move to this side of the country until after that photograph was taken, but I'm wondering if it was around the same time as there appears to be temporary fencing around the cabinet in the background (which houses the control panel), the rail looks fairly new, and the yellow clamplock covers are very clean and unfaded. Images of the control panel are available here: https://photos.swindonpanel.org.uk/picture.php?/539/category/21

That site also has an album of images from Swindon Down Yard showing another example of a yellow GPL worked from a mechanical groundframe (still in situ): https://photos.swindonpanel.org.uk/index.php?/category/48