'Rumble strips' on rail track

[CosherB]

I've noticed at terminal stations, just before the buffers, the track has a criss-cross pattern welded onto it that makes a distinct rumbling sound as the train runs onto it.

First thoughts were that it was there to improve wheel grip if a driver brakes late and is in danger of hitting the buffers, but on reflection it looks as though it would reduce the area of rail contact for the weel and thus be more likely to cause a braked wheel to skid than plain track would.

Then I though the rumbling it makes might be a 'wake up call' to a dozy driver that he'd better stop soon or he'll hit the buffers. But if he's left his braking that late he's going to hit the buffers with a heck of a thump anyway, despite an emergency application when the rumble wakes him up.

So waht are those 'rumble strips' for?

 

[Vulcan]

I believe it is to reduce the surface area of the rail, so that it stays shiny from trains passing over at slow speeds. If the rails get too rusty or dirty it could be possible for a short vehicle to be 'lost' from the track circuits.

 

[EM2]

Exactly as Vulcan says, it's to ensure track circuit continuity.

 

[Vulcan]

I think this is the first time I've known the answer to a question on here and managed to stick my oar in first to take the credit!

I know stuff about railways, me

 

[Trog]

The welded strip is stainless steel, which does not rust hence ensuring a good contact between the rails and wheels for track circuiting. Even if the track is only used very occasionally.

 

[CosherB]

Thanks guys. That makes perfect sense! What a mine of railway info this place is!

 

[A60K]

You'll see it on the Underground as well - sometimes near buffers, but also on some little-used crossovers. I think the east to west crossover on the Met/Circle at Liverpool Street has it.

 

[CarterUSM]

I've only ever seen these in the bay platforms at carlisle, never thought much of them myself, but i'm pleased I know now. It's nice to know these little snippets.

 

[Old Timer]

You'll see it on the Underground as well - sometimes near buffers, but also on some little-used crossovers. I think the east to west crossover on the Met/Circle at Liverpool Street has it.

Farringdon also.

 

[Peter Mugridge]

...and generally known as "wiggly wire", isn't it?

 

[Old Timer]

...and generally known as "wiggly wire", isn't it?

Not heard that one.

I am struggling to remember what we used to call them colloquially when I was involved more than I am now.

 

[A60K]

...and generally known as "wiggly wire", isn't it?

It certainly is on the Underground, don't know about on the mainline network.

 

[Crossover]

To add in my two penneth :P

You will also find it at Manchester Piccadilly on the terminal platforms...I think they may all have it, but certain the likes of 11 and 12 have anyway

I, like CS, thought it may also be to give the drivers a bit of a shake (like rumble strips on roundabouts - and you can feel it as the bogies go across it)/help drivers park the train up to the buffers, but conductivity makes sense I guess :P

Whether its an official colloquialism or not, I think "wiggly wire" is an awesme name for it anyway

 

[Vulcan]

You will also find it at Manchester Piccadilly on the terminal platforms...I think they may all have it, but certain the likes of 11 and 12 have anyway

You'll find it at all terminal platforms at Man Picc, and I would have thought all terminal platform lines where track circuits are in use. Its one of these things that you never notice until your in the leading coach as it rumbles over it to the buffers.

I don't think it is intended in any way to 'wake up' the driver, as I would hope any train driver would be wide awake when driving, especially at that close proximity to the buffer stop.

 

[Peter Mugridge]

I am surprised nobody has heard "wiggly wire" before; that's the only name I've ever heard for it, and that's going back over 30 years!

It is purely to ensure the track circuits operate, as has been stated.

 

[badger1badger]

I've noticed at terminal stations, just before the buffers, the track has a criss-cross pattern welded onto it that makes a distinct rumbling sound as the train runs onto it.

First thoughts were that it was there to improve wheel grip if a driver brakes late and is in danger of hitting the buffers, but on reflection it looks as though it would reduce the area of rail contact for the weel and thus be more likely to cause a braked wheel to skid than plain track would.

Then I though the rumbling it makes might be a 'wake up call' to a dozy driver that he'd better stop soon or he'll hit the buffers. But if he's left his braking that late he's going to hit the buffers with a heck of a thump anyway, despite an emergency application when the rumble wakes him up.

So waht are those 'rumble strips' for?

Well I have found something out - I believed it was to warn the driver that he was appoaching the end of the track - but now a more technical reason and a very sound reason ! could it be a bit of both ?

Cheers

Paul

 

[Vulcan]

From all the engines I've sat in the driver's seat of, I would have said I'd pretty easy to see where the front is and where the buffer stop is in relation to it.

 

[Ploughman]

Often to be found on emergency crossovers as well.
Strensall between York & Malton for example.

 

[Dougman]

Nicely illustrated on page 10 of this report

 

[O L Leigh]

I don't understand why welded zig-zag is required if it is merely intended for track circuit continuity. Terminus lines are well used and not generally subject to surface corrosion, so operation of track circuits shouldn't be compromised. Likewise, it's use is not universal. We have only one very small section of zig-zag, and that is inside Ilford depot. None of our bay platforms, dead-end lines or emergency crossovers have it.

If a train is going to disappear from the panel due to problems operating track circuits it is much more likely to be somewhere in the back of beyond on a lightly used line. Those classes of train particualrly prone to this problem are fitted with track circuit actuators (TCA) that ensure an adequate current is maintained across the axle to ensure that the track circuit shows "occupied".

O L Leigh

 

[Old Timer]

Hello chap.

The running surface metal strips pre-date TCAs.

They were installed on crossovers and headshunts which were not heavily used in order to assist with train detection.

 

[O L Leigh]

I guessed they might be a relic from an older and more innocent time, hence their inconsistent use. I guess it must also pre-date permissive working which is why you only find it a carriage length or so out from the buffer stops and not down the entire length of the platform.

O L Leigh

 

[sheff'd victoria]

I've only ever seen these in the bay platforms at carlisle, never thought much of them myself, but i'm pleased I know now. It's nice to know these little snippets.

Also in the bay platforms of number 3 & 4 at Sheffield Midland

 

[Old Timer]

I guessed they might be a relic from an older and more innocent time, hence their inconsistent use. I guess it must also pre-date permissive working which is why you only find it a carriage length or so out from the buffer stops and not down the entire length of the platform.O L Leigh

On elocation where you would find them was at the buffer stop end of terminal platforms, where locos would occasionally stand. The reason for this was that it would be possible for a locomotive to be "lost" and the platform entry signal clear to a yellow (or in previous days a green) rather than a sub signal.

Another situation would be a crossover where it would be undesirable to "lose" a locomotive or unit passing through it, as the points could be normalised underneath the movement.

 

[Bill EWS]

I remember reading about the Wiggly Wire system many years go. It was a completely different set-up to the zig-zag surface that came much latter. I don't know if they are still around but you had the zig-zag strips at some places, as you approached the points at bi-signalling junctions.

I google'd "Wiggly Wire System" and came up with this interesting web page article.....

http://www.old-dalby.com/mtesting.htm

 

[Trog]

The short sections of stainless steel zig zags near terminal buffers, were probably also there to detect the presence of a single van sitting on the buffers, back in the days when adding odd vans as tail loads was common practice. As these being light and short wheeel base could be sitting on the rusty rails right next to the buffers that would not usually be used, and hence not be detected by the standard track circuiting. You also sometimes see track depression bars used for the same reason.

 

[bengley]

Rickmansworth platform 3 has this.

 

[Maxfly]

certainly at least one of the platforms at Leeds has them. pretty sure when they were explained to me it was not just because of corrosion but also the build up of oil, grease and general ****e that is not easily cleared by the wheels at low speeds

 

[driver9000]

Another situation would be a crossover where it would be undesirable to "lose" a locomotive or unit passing through it, as the points could be normalised underneath the movement.

Wigan North Western has an example of this on the crossover just south of the station between the Up & Down Loop and Down Main (Platforms 5 & 6) although this connection is rarely used now. I was always told the rumble strips were for Track Circuit occupation purposes and most of the terminal platforms I work into have them, only very recent renewals has seen them disappear.

 

[fgwrich]

tis often found at several level crossings on various branchlines - Par to Newquay & even the mid norfolk railway to name a few...