Where will the last semaphore signals be on the national network?

[Western 52]

I think there's still a semaphore gantry at Llandudno? Is that the only one left now, or maybe another somewhere?

 

[zwk500]

I think there's still a semaphore gantry at Llandudno? Is that the only one left now, or maybe another somewhere?

Depending on the distinction between a gantry and a Bracket, there's probably a few around Shrewsbury.

 

[Highlandspring]

Is that the only one left now, or maybe another somewhere?

There’s a nice gantry at Hilton Junction which is, incidentally, Scotland’s oldest signalbox dating from 1873.

 

[DorkingMain]

That is an interesting point - assuming the current arrangement is considered safe to operate (obviously)

Yes and no.

By current standards, it isn't safe to operate. But it's operated on grandfather rights, on the basis of "this is the safest thing we can do with the current infrastructure", because the alternative is closing it all, or ripping it all out and shuffling it about at great expense.

 

[John Webb]

Yes and no.

By current standards, it isn't safe to operate. But it's operated on grandfather rights, on the basis of "this is the safest thing we can do with the current infrastructure", because the alternative is closing it all, or ripping it all out and shuffling it about at great expense.

Regarding Shrewsbury, by the time it is replaced I would expect a new signalling system to be much better at checking train speeds as they enter the station and thus controlling their approach to the platform end junctions with accuracy not currently achievable, thus compensating for the lack of overlaps at the junctions.

 

[zwk500]

Regarding Shrewsbury, by the time it is replaced I would expect a new signalling system to be much better at checking train speeds as they enter the station and thus controlling their approach to the platform end junctions with accuracy not currently achievable, thus compensating for the lack of overlaps at the junctions.

Like ETCS, you mean? (Sort of).

 

[John Webb]

Like ETCS, you mean? (Sort of).

Something along those lines (deliberate pun there!)

 

[Annetts key]

Just a reminder: the reason for overlaps is two fold, first, to mitigate driver error (late braking, distraction, loss of concentration) and secondly, possible loss of braking performance (wet/slippery rails, wheel slide, braking system fault).

The standard overlap is a nominal 200 yards / 183 metres in length. But a reduced overlap of 50 yards / 183 metres can be used if the line speed is low, or the preceding signal is approached released (approached controlled) from red (and hence, the approach speed of the train is reduced).

Alternatively, it may be possible to have swinging overlaps, if it is possible for the points ahead of the signal to move, and so provide an alternative length of track that will now form the overlap distance.

In special circumstances, it appears it is possible to have modern colour light signalling with no overlap or very short overlaps. See the signalling at Bristol Temple Meads for an example, especially the mid platform signals.

 

[Y Ddraig Coch]

I think there's still a semaphore gantry at Llandudno? Is that the only one left now, or maybe another somewhere?

Indeed there is still a gantry, it is a semaphore as far as Deganwy then Llandudno Junction box takes over with lights.

 

[MadMac]

Indeed there is still a gantry, it is a semaphore as far as Deganwy then Llandudno Junction box takes over with lights.

I think the junction signal at Hilton Junction is still a gantry?

 

[John Webb]

Indeed there is still a gantry, it is a semaphore as far as Deganwy then Llandudno Junction box takes over with lights.

Gantry was still at Llandudno in 2017 (click on photo to go to the larger original on the Geograph website):
Six signals and a signal box

© Copyright Richard Hoare and licensed for reuse under this Creative Commons Licence.

 

[Y Ddraig Coch]

Gantry was still at Llandudno in 2017 (click on photo to go to the larger original on the Geograph website):
Six signals and a signal box

© Copyright Richard Hoare and licensed for reuse under this Creative Commons Licence.

It is still alive and well today I assure you.

 

[LowLevel]

A very famous and historical structure it is too - I believe it is the surviving portion of the original LNWR Rugby gantry on the WCML.

Rugby Station - Rugby's Signal Gantry prior to the construction of the Great Central bridge carrying the new railway over the LNWR mainline

(Link to a Web page featuring a photo of the original gantry in place at Rugby).

 

[John Webb]

I think the junction signal at Hilton Junction is still a gantry?

It was a year or so ago:
Hilton Junction

© Copyright A MELVILLE and licensed for reuse under this Creative Commons Licence.

 

[Western 52]

Does the gantry at the north end of Shrewsbury platforms 3 and 4 still have any semaphore arms on it?

 

[John Webb]

Does the gantry at the north end of Shrewsbury platforms 3 and 4 still have any semaphore arms on it?

It did in 2017:
Shrewsbury Railway Station - end of Platform 3

© Copyright Colin Cheesman and licensed for reuse under this Creative Commons Licence.

Much simplified and rebuilt since 1957:
Stopping train from Chester entering Shrewsbury

© Copyright Ben Brooksbank and licensed for reuse under this Creative Commons Licence.

 

[Tomnick]

I can't see Shrewsbury being resignalled any time soon. For one thing you'd lose shedloads of platform capacity as the new design would have to be compliant with modern standards and include irritating details such as signalling overlaps etc! The current arrangement with fixed distants and junctions right on the end of platforms can't be easily recreated with MAS without losing critical capacity and operational capabilities.

Modern standards? The principle of the overlap, or the clearing point in the context of an Absolute Block section, has been around for much longer than a century - and in that context it is of course equally applicable to the current installation around Shrewsbury. A junction right on the end of a platform doesn't mean that you can't have an overlap - it just means that it might extend over the junction (as would typically be the case with Absolute Block acceptance conditions).

 

[Wilts Wanderer]

Modern standards? The principle of the overlap, or the clearing point in the context of an Absolute Block section, has been around for much longer than a century - and in that context it is of course equally applicable to the current installation around Shrewsbury. A junction right on the end of a platform doesn't mean that you can't have an overlap - it just means that it might extend over the junction (as would typically be the case with Absolute Block acceptance conditions).

Only at Shrewsbury it doesn’t - for instance I don’t believe there is any restriction on a northbound arrival into P4 while a southbound train crosses from the Gobowen line into P7.

Similarly Birmingham New Street is signalled without overlaps - which is why there is a 10mph limit. Both layouts have grandfather rights and could not be so designed as a new installation today. In both cases the lack of overlaps is mitigated by fixed distants and a severely restricted linespeed, which would require a lot of difficult derogations against modern design standards.

 

[Annetts key]

Similarly Birmingham New Street is signalled without overlaps - which is why there is a 10mph limit. Both layouts have grandfather rights and could not be so designed as a new installation today. In both cases the lack of overlaps is mitigated by fixed distants and a severely restricted linespeed, which would require a lot of difficult derogations against modern design standards.

See post #128…

 

[najaB]

But replacement parts are normally made by either the original manufactures, the company that bought/merged with the original company, or another company (e.g. Unipart which bought the National Railways Supplies company, a part of the former BR stores system). When it becomes uneconomic for either Network Rail to buy replacement parts, or uneconomic for the company to produce new parts, then at some stage the railway will have to fit more modern equipment.

This might have been mentioned further down the thread, but the rise of 3D metal printing may make this less of a concern. As long as you have an example of what the part is like as new then it is relatively simple to reproduce a new one. Even with quite complex mechanisms.

 

[Llanigraham]

You never know. However, the box equipment has been declared life expired, as I understand it.

I seem to remember that being said about the equipment in my old Box, even before I laft, and it is still there and it's closure has slipped back so many times now no-one believes any date.

 

[Bobdogs]

Ferryside, Pembrey and Burry Port.
Are there any plans to close the five signal boxes west of Llanelli on the South Wales main line?

 

[Western 52]

I live near Pembrey box, which has recently had new windows, so maybe safe for a while. Still some wire pulled semaphores here, but the days when there were over 80 levers used have long gone! Ferryside has had new windows too.

 

[D6130]

I live near Pembrey box, which has recently had new windows, so maybe safe for a while. Still some wire pulled semaphores here, but the days when there were over 80 levers used have long gone! Ferryside has had new windows too.

Be careful what you wish for! In BR days we always used to say that if a station or signalbox received any major repairs, a repaint or even new windows, it would be closed within a year. There were numerous examples of this back in the 'seventies and 'eighties....Helensburgh Upper station building being a prime example.

 

[Western 52]

Be careful what you wish for! In BR days we always used to say that if a station or signalbox received any major repairs, a repaint or even new windows, it would be closed within a year. There were numerous examples of this back in the 'seventies and 'eighties....Helensburgh Upper station building being a prime example.

Very true! I've heard such stories too. The signals here look rather neglected and could do with some paint, but at least they are still here.

 

[BS56]

Just read that NR have signed a contract with a major signalling company to install new signalling in Cornwall and Devon . The signal boxes at Exeter and Plymouth will control one county each. So it looks like in a few years time the west country will not be the last place to see semaphore signals.

 

[Llanigraham]

I live near Pembrey box, which has recently had new windows, so maybe safe for a while. Still some wire pulled semaphores here, but the days when there were over 80 levers used have long gone! Ferryside has had new windows too.

It was always said that if they came and started to paint the Box or do it up in any way it was sure to be closed soon!

 

[Ashley Hill]

Cornwall has been mentioned above but what is the Devon resignalling you mention,getting rid of Exeter's fringe boxes?

 

[Gloster]

Cornwall has been mentioned above but what is the Devon resignalling you mention,getting rid of Exeter's fringe boxes?

A bit of googling produces several articles, all of which look as though they are based on the same press release. Based on that my interpretation is that it is the work mentioned above. Exeter to take over Lostwithiel, Par and Truro, while it is not clear what they are doing at Plymouth. In particular they mention two level-crossings being involved: I would see this as Lostwithiel and Truro, and so presume they are not going further west.

 

[Ashley Hill]

A bit of googling produces several articles, all of which look as though they are based on the same press release. Based on that my interpretation is that it is the work mentioned above. Exeter to take over Lostwithiel, Par and Truro, while it is not clear what they are doing at Plymouth. In particular they mention two level-crossings being involved: I would see this as Lostwithiel and Truro, and so presume they are not going further west.

That's my understanding of it too. I was just thrown by the addition of Devon resignalling by the poster.