Signalling, modern and old?

[truckman060473]

Why do certain locations on main lines retain semaphores? For example down my way - Ferryside and Burry Port. Don't get me wrong, it's great to see them, but you'd think in this modern world obsessed with health & safety that it would be insisted upon for them to be replaced with new L.E.D. high brightness coloured signals.

 

[The Planner]

M o n e y, and the fact the level of service probably doesnt require any different

 

[John Webb]

The semaphore system is well-established and quite robust. As the Planner says, it's mostly a matter of money and also a sense of 'If it ain't broke don't fix it' as well. It may be that they are waiting to see if any final decision is to be made about electrification in the area before considering any signalling replacement.

 

[PinzaC55]

Also semaphore signals have what is known as "grandfather rights". In a situation where you have a semaphore protecting a level crossing it may be only a few feet from the crossing. If you wish to replace it with a colour light it has to conform to the new standards which (I think) say it has to be a minimum of 50 metres from the crossing. This causes all kinds of problems as it did at Poppleton near York where a new signal was erected in 1990 but they realised they'd have to double the length of the platform, so the signal was never brought into use.It stood covered over for 15 years and has now been removed. :roll:

 

[Zoe]

Considering ERTMS without lineside signals is on the horizon there wouldn't be much point in a resignalling scheme that would have a short lifetime.

 

[DaveNewcastle]

. . . ERTMS without lineside signals is on the horizon . . . . .

Ah yes, you're right. Isn't that the horizon that the pigs fly over?

 

[The Planner]

Considering ERTMS without lineside signals is on the horizon there wouldn't be much point in a resignalling scheme that would have a short lifetime.

Not the view taken at all, if it was then New St, Wolves, Bletchley, Northampton, Walsall, Stourbridge, Stafford, Norton Bridge, Water Orton, Reading, Cardiff etc etc... wouldn't be happening and Newport, Coventry, WCML etc etc wouldnt have happened !!

 

[Zoe]

To be fair the WCML has been done and will have a fair bit of life before a further ERTMS resignalling. This won't be the case in the future. I remember when Labour published the original GWML electrification plans it was to include ERTMS also.

 

[The Planner]

You are looking at a lifespan of 30-40 years for a re-signalling scheme. If ERTMS was the saviour of it all it would be rolling out a lot more than it is now. ERTMS is meant to be overlayed on the GWML at some point, but sticking it on that compared to the Cambrian makes the mind boggle....

 

[Bittern]

It's actually remarkable that these signals have remained in service for so long. Did any of the active Semaphores start their lives with the Big Four or have these been replaced by BR/NR with 'modern' Semaphores?

 

[Zoe]

You are looking at a lifespan of 30-40 years for a re-signalling scheme.

So what's the point in committing to resignalling schemes designed to last 30 - 40 years then when in reality they may well last much less than that?

 

[Railsigns]

So what's the point in committing to resignalling schemes designed to last 30 - 40 years then when in reality they may well last much less than that?

Because introducing ERTMS doesn't necessarily entail getting rid of all the existing signalling infrastructure. Most signalling equipment installed nowadays is required to be ERTMS-compatible; ERTMS still needs an interlocking and it still needs a train detection system (axle counters or track circuits). Nor does fitting ERTMS necessarily mean there will be no lineside signals. You can overlay ERTMS onto a railway and keep the colour light signals so that non-ERTMS fitted trains can still run. That's what will be happening on the GWML; ERTMS will be overlaid onto conventional signalling and it won't be until many years later that the signals will be taken away. There will be large conventional resignalling schemes for decades to come, and as long as they come with ERTMS-compatible equipment they can be viewed as a stepping stone towards ERTMS, as opposed to completely abortive work.

 

[Zoe]

ERTMS will be overlaid onto conventional signalling and it won't be until many years later that the signals will be taken away.

I thought ERTMS level 2 without lineside signals was to be installed not ERTMS level 1 which uses existing infrastructure. If what you say is that case then by that time I would expect technology to be sufficiently advanced to allow driverless operation. Driverless cars are on the horizon so why not trains?

 

[Railsigns]

By that time though I would expect technology to be sufficiently advanced to allow driverless operation. Driverless cars are on the horizon so why not trains?

Well, that's a completely different question to the one you originally asked. No doubt the technology is available but it all comes down to money and also the question of public perception and whether the disbenefits of not having a human being at the front of every train (when things go wrong) outweigh the benefits.
--- old post above --- --- new post below ---

I thought ERTMS level 2 without lineside signals was to be installed not ERTMS level 1 which uses existing infrastructure.

ERTMS level 2 is being used, both with and without lineside signals; either way, both can make use of existing equipment as long as it's compatible.

 

[Metroland]

M o n e y, and the fact the level of service probably doesnt require any different

And the fact that semaphore signalling lasts an age compared to the modern equivalent. Signalling frames dating from the Victorian era are still in service (relatively simple and robust) compared to 1960s PSBs like Saltley, Trent etc that are now life expired. Even 1980s installations like Leicester and Exeter are getting past their sell-by data because of the quality of wiring.

BR never got around to developing a really cost effective double track low cost scheme for regional lines, so I guess with budgets being as they are some boxes were just left in. That said, surprisingly some mechanical signalling (albeit level frames controlling mostly colour lights) remain on significant main lines: Banbury, Stafford, Stockport, Crewe coal yard are obvious examples. But large areas of the southern commuter network are still controlled from old style signalboxes, and mechanical signalling remains on lines like Poole-Wool, Ely-King's Lynn even though were electrified in the 1980s. Even the recent Cotswold line redoubling scheme will leave local signal boxes in places in many locations, because it's not quite cost effective to go the whole hog and stick the control area on Thames Valley signalling centre.

 

[The Planner]

The Cotswolds is a slightly different kettle of fish, read cost effective as being "we've run out of cash".

 

[driver9000]

It's actually remarkable that these signals have remained in service for so long. Did any of the active Semaphores start their lives with the Big Four or have these been replaced by BR/NR with 'modern' Semaphores?

There are some beautiful GWR Somersault signals still in use, but the the name of the station they are at has escaped me (I can't find the photo of them since Fotopic went under)

Have a look at this link which has some old centre pivot signals at Severn Bridge Junction, the photographs are recent.

http://www.roscalen.com/signals/Shrewsbury/SevernBridgeJunction.htm

 

[matchmaker]

It's actually remarkable that these signals have remained in service for so long. Did any of the active Semaphores start their lives with the Big Four or have these been replaced by BR/NR with 'modern' Semaphores?

Many remaining posts are pre-BR. In fact, lattice post signals may well be pre-grouping. Stirling, for example, retains many Caledonian posts. The last lower quadrant Caledonian signal survived at Stirling as late as 2000.

http://www.signalbox.org/gallery/sc/stirlingmiddle.php

 

[MrC]

and mechanical signalling remains on lines like Poole-Wool

Not long for this world though.

 

[strange6]

There are some beautiful GWR Somersault signals still in use, but the the name of the station they are at has escaped me (I can't find the photo of them since Fotopic went under)

Have a look at this link which has some old centre pivot signals at Severn Bridge Junction, the photographs are recent.

http://www.roscalen.com/signals/Shrewsbury/SevernBridgeJunction.htm

That signalbox is a real beauty - just look at the size of the thing!

 

[PinzaC55]

They are not somersault signals - the GWR didn't use that type of signals unless you count one or two of the minor Welsh lines, I think. These are conventional lower quadrant signals for restricted clearance with the spectacles moved to the left of the post.

THIS is a somersault signal at Thorpe Culvert on the Skegness line which I photographed in 1990.

http://www.flickr.com/photos/pinzac55/3786859618/

On a somersault signal the arm stands completely clear of the post when it is "pulled off".

 

[driver9000]

They are not somersault signals - the GWR didn't use that type of signals unless you count one or two of the minor Welsh lines, I think. These are conventional lower quadrant signals for restricted clearance with the spectacles moved to the left of the post.

THIS is a somersault signal at Thorpe Culvert on the Skegness line which I photographed in 1990.

http://www.flickr.com/photos/pinzac55/3786859618/

On a somersault signal the arm stands completely clear of the post when it is "pulled off".

You're quite right, I didn't break my post up properly. I found the link to the centre pivot ones and thought they were interesting enough to add while I searched for the photograph (or similar) I've seen....not having much luck either!

 

[Class172]

I think that in areas that still retain a good large set of semaphores, any new or replacements should be semaphores as well, unless it's completely necessary to have LED signals. Some excellent examples are at Worcester, Droitwich Spa & Shrewsbury. The first two are due to be resignalled in the next few years but it has been confirmed that they will both retain their signal boxes (not have a single control centre) due to their location and importance - not money!

http://www.roscalen.com/signals/DroitwichSpa/index.htm
http://www.roscalen.com/signals/Worcester/index.htm
http://www.roscalen.com/signals/Shrewsbury/index.htm

 

[Zoe]

I think that in areas that still retain a good large set of semaphores, any new or replacements should be semaphores as well, unless it's completely necessary to have LED signals. Some excellent examples are at Worcester, Droitwich Spa & Shrewsbury. The first two are due to be resignalled in the next few years but it has been confirmed that they will both retain their signal boxes (not have a single control centre) due to their location and importance - not money!

Would have thought they would eventually both go into either Saltley or the Thames Valley Signalling Centre.

 

[The Planner]

Worcester and Shrewsbury are a long way off, they can't decide what to do with them yet. Worcester would go to Saltley, Shrewsbury to Cardiff.

 

[brillopad]

Liskeard ??

 

[Class172]

I've read that the Worcester area won't go to saltley, it will remain separate due to it's location - if anything it'll merge with other areas in worcestershire and herefordshire.

 

[The Planner]

Can't see it. Id speculate on Hereford going to Cardiff along with everything down the Marches, possibly along with Ledbury, Malvern, Henwick and Newland East. Gloucester will probably end up in Saltley at some point too along with Walsall and the Chase boxes, Aston, Wolves, Banbury and Leamington. Evesham, Moreton, Ascott and Oxford will go to Didcot.

 

[Bald Rick]

But large areas of the southern commuter network are still controlled from old style signalboxes, and mechanical signalling remains on lines like Poole-Wool, Ely-King's Lynn even though were electrified in the 1980s.

Ely-King's Lynn has big levers in old signalboxes, but it's mostly electrical interlocking and colour lights, save for a small oasis of heritage up at King's Lynn Jn SB for the Middleton Towers branch.

Running out of money used to happen in the "good" old days as well, there is a large empty space on Panel C at Cambridge PSB for the line all the way to King's Lynn.

 

[SteamontheMet]

It's actually remarkable that these signals have remained in service for so long. Did any of the active Semaphores start their lives with the Big Four or have these been replaced by BR/NR with 'modern' Semaphores?

Greenford in North West London still retains its LQ Semaphores to this day with a few being moved around due to the singling of the track, the ones at Greenford South Jnc are being replaced by the LED lights.

http://www.roscalen.com/signals/Greenford/index.htm

If HS2 gets to go ahead then the exisiting Semaphores will disapear as the planned route is to run over the Existing Old Oak Common - Northolt Jnc.