Semaphore signals and electrification

[krus_aragon]

Do line electrification and electric signalling go hand in hand? Are colour signals required for electric trains, or is it just that routes important enough to be electrified will already be important enough to have their semaphores replaced?

 

[Old Timer]

Do line electrification and electric signalling go hand in hand? Are colour signals required for electric trains, or is it just that routes important enough to be electrified will already be important enough to have their semaphores replaced?

There is no requirement for mechanical signalling to be for electrification, per se.

There may well however be benefits from undertaking re-signalling at the same time in order to simplify a layout to make the OHL Equipment wire runs and feeding less complex.

In some cases mechanical signals may not be sufficiently separated from the OHL Equipment and would thus need to be altered or their positioning changed.

Once a signal is altered in any way however, it becomes subject to quite stringent requirements, which by virtue of what they now are will almost without exception create a domino effect requiring other signals to be altered, which in turns requires further signals to be altered, etc, etc.

 

[DaveNewcastle]

. . . will . . . create a domino effect . .

A domino effect of semaphore signals! What a lovely picture THAT conjures up! I can just imagine a row of signals fading into the distance with their red arms dropping one after each other!

Seriously, I can't for the momment think of any location with both semaphore and OHLE. But I'm sure OT is correct that this isn't a necessary link rather than a result of having to upgrade if a signal has to be moved.
And thre must be very few locations where the localness of control of semaphore signals has any long-term need to be locally controlled. Level crossings perhaps, and (not electrified admittedly) exceptional breaks in track access such as the swing bridges we saw last week at either end of the Caledonain Canal.

 

[TDK]

A domino effect of semaphore signals! What a lovely picture THAT conjures up! I can just imagine a row of signals fading into the distance with their red arms dropping one after each other!

Seriously, I can't for the momment think of any location with both semaphore and OHLE. But I'm sure OT is correct that this isn't a necessary link rather than a result of having to upgrade if a signal has to be moved.
And thre must be very few locations where the localness of control of semaphore signals has any long-term need to be locally controlled. Level crossings perhaps, and (not electrified admittedly) exceptional breaks in track access such as the swing bridges we saw last week at either end of the Caledonain Canal.

There is a few semaphore shunt discs at Oxley

 

[Old Timer]

If my aged memory serves me right there were minature arms in the Willesden yards, and coming of the Down Sidings at Northampton at the north end of what is now the EMU Depot.

I think that there were also some in the Stoke area.

We are going back to the 60s and 70s here though, to days when life was much simpler and more interesting..

 

[Kneedown]

If i remember rightly there was a fair bit of semaphore signalling on the old Woodhead route.
More recently i can only think of a few shunt signals in the Stoke on Trent area before that was resignalled.
Off topic a little, but a previous poster mentioned swing bridges. I frequently drive over the one at Trowse just outside of Norwich and have often wondered whether there are any more electrified swing bridges anywhere, or if it is unique?

 

[JustinStacey.x]

There are plenty of non electrified routes up here in Scotland which use 'traffic light' style signalling.

 

[GB]

Up untill very recently there were a couple of semaphores at Frinton and a Shunt Disc at Clacton.

http://www.east-rail.fotopic.net/p55537948.html

 

[DaveNewcastle]

Off topic a little, but a previous poster mentioned swing bridges. I frequently drive over the one at Trowse just outside of Norwich and have often wondered whether there are any more electrified swing bridges anywhere, or if it is unique?

I think you're right, that it IS unique.
Does it open often? And is it reliable?

 

[GB]

I think it only opens occassionly and only then thats just usually a test.

I was suprised to learn the other day that the OHL power is still live even when the bridge has swung open as the power cables actually go under the river bed.

 

[DaveNewcastle]

(Smiling at the thought of a loco on the bridge and wanting to take power while the bridge is in the open position!)
That is unexpected, but isolating and switching the power would only introduce more equipment, more automated and manual checks, and more monitoring, hazards, signalling and reporting. Its not as if we isolate the OHLE at level crossings or over lines when the route is set against them.

 

[Kneedown]

I think you're right, that it IS unique.
Does it open often? And is it reliable?

Never seen it open, but as i'm always driving over it when i see it thats probably a good thing!
As to reliability it's not too bad AFAIK. It has it's own signalbox for use during difficulties.

 

[krus_aragon]

Thanks for all the replies, this is really interesting stuff.

There are plenty of non electrified routes up here in Scotland which use 'traffic light' style signalling.

I was asking mainly about the other way around: electrified routes with semaphores. There are traffic light signals in several areas of Wales, but not an inch of electrification. Sorry if I was unclear on that.

 

[33056]

If my aged memory serves me right there were minature arms in the Willesden yards.........

They are still there, assuming that you mean the ones in the "Carriage" at Wembley / Stonebridge Park.

 

[Oracle]

I have shots of some signals in Willesden Carriage Sdings. Both the ones I know of, CN15 [operated by Willesden Carriage Sisings South 'box?] and CN25 [Down operated by Willesden carriage Shed North 'box] Carriage Linehave metal grids facing away from the sempahiore arms. I think that there may be more semaphores in addition to those two? Shunt signals seem to be discs.

 

[yorksrob]

There were certainly plenty of semaphore signals on the third rail network when I was growing up (Canterbury East and West spring to mind) and that was about 30 years after electrification. That said if you're electrifying somewhere you're probably as well updating the signalling and everything else so that your passengers notice an improvement in reliability.

 

[25322]

Stafford 4 still has mechanical signals in use and thats near the middle of the WCML. Albeit only Ground/shunt disks.

Part of the reason for the removal of semaphores is that when raised (off) they come closer to the overhead equipment and more likely to arc over in wet weather. Also most semaphore sticks (posts) are taller than the current eye level of the red aspect on a colour light.

The smaller arms on signals are generally only used on lines that are freight loops

 

[Metroland]

Also Stockport and several other locations on the WCML. Woodhead (although DC) also had semaphores and some of the post war electrification on the great eastern also left many semaphores in place.

The main reason resignalling tends to take place during electrification is track circuits, as one of the rails is used for the return. There are also effects on other equipment, and various things need to be bonded. Often resignalling takes place because the line is undergoing a general upgrade anyway for a new service.

 

[mallard]

There were certainly plenty of semaphore signals on the third rail network when I was growing up (Canterbury East and West spring to mind) and that was about 30 years after electrification. That said if you're electrifying somewhere you're probably as well updating the signalling and everything else so that your passengers notice an improvement in reliability.

There's at least one left in Canterbury, on the line south of Canterbury East near the Old Dover Road bridge. (Saw it from the upper deck of a bus just over a week ago.) Probably more around, but I haven't been through there on a train recently.

 

[AlexS]

There's lots of discs at Oxley and also one single running signal on a post at the yard neck at the south end.

I suspect this is probably the only lower quadrant running signal that controls electrified railway.

It's even still got it's GWR finial but it's not in brilliant condition as a post.

 

[HSTfan!!!]

majority of the GWML will have been resignalled to the 2 lense signals (certainly between bristol and swansea) before electrification even starts as far as I know

 

[The Planner]

There's lots of discs at Oxley and also one single running signal on a post at the yard neck at the south end.

I suspect this is probably the only lower quadrant running signal that controls electrified railway.

It's even still got it's GWR finial but it's not in brilliant condition as a post.

Wont last, Oxley is getting a bit of a re-vamp signalling wise soon.

 

[SWT Driver]

There used to be some at Holmwood & Warnham on the Dorking to Horsham line, but I believe they've since been removed.

The other places that still have semaphore signals with 3rd rail electrification is Billingshurst, Pulborough & Amberley in West Sussex on the Arun Valley line, how much longer they last is anyone's guess, but they do bring a certain country charm to the line.

 

[starrymarkb]

majority of the GWML will have been resignalled to the 2 lense signals (certainly between bristol and swansea) before electrification even starts as far as I know

Though there will eventually be no lineside signals as the route is supposed to be getting ETCS at the same time...

Does ETCS have the "bus stop" flags like TVM?

 

[paul1609]

There used to be some at Holmwood & Warnham on the Dorking to Horsham line, but I believe they've since been removed.

The other places that still have semaphore signals with 3rd rail electrification is Billingshurst, Pulborough & Amberley in West Sussex on the Arun Valley line, how much longer they last is anyone's guess, but they do bring a certain country charm to the line.

The Dorking to Horsham Line was converted to Colour light signalling last year as was the Bognor Branch. Semaphores remain at Littlehampton as well as the locations you have mentioned.

 

[O L Leigh]

Up untill very recently there were a couple of semaphores at Frinton and a Shunt Disc at Clacton.

http://www.east-rail.fotopic.net/p55537948.html

The semaphore signals at Frinton-on-Sea were apparently the last such signals on Network Rail metals to be operational on a line electrified using 25kV AC OLE, but were removed on the night of 17-18 April 2009 as part of the GE route modernisation scheme together with the old manual gates.

However, as the Frinton line was electrified way back in the 1960's, it shows that electrification and re-signalling schemes do not necessarily go hand in hand.

O L Leigh

 

[Oracle]

I assume that that is passenger line? Unless the Willesden Carriage Sidings signals have been replaced recently.

 

[SREW]

Hi all,
A picture to show a minarture with 25KV at Eastfield, Peterborough