Signalling cable question

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ryan125hst

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I have travelled between Retford and Sheffield quite a lot over the last couple of years due to the fact that I am a student at Sheffield Hallam University. One thing that I have noticed and, as yet, have failed to get a photo of, is a green cable that seems to run for most of the way and isn’t buried at all. I’m assuming it’s part of the signalling system? It’s puzzled me for a while, particularly given how exposed it appears to be as well as the fact that it just seems to be dumped where it lies. It doesn’t look like it has been neatly laid with any thought at all really.

Does anyone what it is? I’ll be heading back to Sheffield in a couple of weeks so I might be able to get a photo then if it helps, although I don’t know how well it’ll take.

And while on the topic of signal cable management, why have they chosen not to use troughs for cabling when they upgraded the signalling in the Retford area (Lincoln to Sheffield line). The cabling on the ECML seems to be in troughs as I remember seeing them when standing on platform 2 (they may have moved it now though due to the alterations for the new Network Rail Track Maintenance Train that is stabled in Retford down sidings). I went on a walk with my Mum last week which goes in parallel with the line (just near Retford Golf Course) and what look like fairly flimsy bits of wood can be seen all the way along the track carrying several cables. Given the issue of copper theft plus the fact that any damage to the cable would cause disruption, why has it been decided to do this? Surely the fees caused by delays alone would make it a viable extra cost to make the cables a bit more hidden?

I have attached photos below that I took of this while on the same walk last year.
 

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Railsigns

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The green cable is Double Insulated Super Armoured Cable (DISAC) fibre cable. It's designed to be laid on the surface.

More info.
 

ryan125hst

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The green cable is Double Insulated Super Armoured Cable (DISAC) fibre cable. It's designed to be laid on the surface.

More info.

Thanks for that Railsigns. I see that document has a photo of it confirming that it is the cable I was on about. Despite the fact that it is designed to be laid like that, I still find it odd that it is literally dumped on the side of the track- even the photo shows it as such. I wonder why they don't lay it more neatly?

Do you know what it carries? I'm assuming it's related to communications, maybe Network Rail's new phone system? I would say signalling to replace the multicore cables as I've heard that's been done as well, but I'm sure I've seen that cable all the way along the route between Retford and Sheffield, even in areas where the signalling hasn't been upgraded.
 

Ploughman

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It also gets in the way of renewal work.
Vegetation clearance when its laid over bushes or caught on branches.
Should have been buried but its cheaper to surface lay even when there is a trough route available.
 

ryan125hst

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I can imagine it must be a nightmare during engineering work as you say. Surely it makes this more expensive, so any savings made when the cable was laid ends up being lost due to the increased time taken during renewal works. Even more so if the cable gets damaged!
 

Bald Rick

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I can imagine it must be a nightmare during engineering work as you say. Surely it makes this more expensive, so any savings made when the cable was laid ends up being lost due to the increased time taken during renewal works. Even more so if the cable gets damaged!

Putting cable in a cable route costs a lot of cash; and on a rural /secondary route this cost is much, much more than any additional costs incurred during engineering works etc.
 

D Foster

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Another consideration is that fibre optic cable has absolutely no scrap value - so there is no need to bury it to hide it or to make it more difficult to steal. :|

Also, as well as being expensive - due to the labour involved in opening out a few miles of troughing - working in the cable and then putting all the troughing back straight - and - like any box of house-removals goodies - it never goes back the same... As well as that - the job is an absolute swine of bending and lifting for the teams that get lumbered with it. There are significant risks of back injury and trapped fingers... Nothing difficult about lifting a troughing lid and putting it back? try a few hundred of them at night and see what your shoulders, back and legs think then...
 
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ryan125hst

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Putting cable in a cable route costs a lot of cash; and on a rural /secondary route this cost is much, much more than any additional costs incurred during engineering works etc.

I guess if it is that much more expensive to do then it does make sense, even if it does look a bit untidy.

D Foster said:
Another consideration is that fibre optic cable has absolutely no scrap value - so there is no need to bury it to hide it or to make it more difficult to steal.

It doesn't stop the thieves from nicking it and then realising it's worthless, but by then the damage has been done and the rail services are disrupted.

D Foster said:
Also, as well as being expensive - due to the labour involved in opening out a few miles of troughing - working in the cable and then putting all the troughing back straight - and - like any box of house-removals goodies - it never goes back the same... As well as that - the job is an absolute swine of bending and lifting for the teams that get lumbered with it. There are significant risks of back injury and trapped fingers... Nothing difficult about lifting a troughing lid and putting it back? try a few hundred of them at night and see what your shoulders, back and legs think then...

It sounds like that troughing is a bit of a nightmare if that's the case so there's no wonder they don't use it if they don't need to. Do they use troughs anywhere on the network now when they're renewing the signalling?
 

68000

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Cable route is one of the biggest headaches and costs involved in S&T renewal work. The existing route is usually in a state of disrepair because it is not maintained. Laying troughs takes a long time as well being labour intensive

Unfortunately, DISAC fibre is hard to get nowadays

That DISAC was probably put in by the FTN Project and will be the backbone of the railway transmission system
 

mr_towers

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{SNIP} Do they use troughs anywhere on the network now when they're renewing the signalling?

They're certainly doing so as part of EGIP - though this probably has something to do with the 25kv string going in too. I've watched some of the teams renewing/repairing/installing it and it definitely doesn't look fun.
 

edwin_m

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Newer forms of troughing comes in smaller/lighter sections so less hazardous.

I would have thought a loose cable wouldn't be allowed in the cess where someone could trip and fall onto the track.
 

D Foster

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There have been all sorts of attempts to create "lightweight" troughing for decades. Some have been loudly trumpeted as the "next new thing" - but one rarely sees them used much. When one does see some of them they are often in various degrees of disrepair - largely depending on age. A look along the lines between Stafford and Crewe will show a fine example of "lighter" troughing falling apart in a number of places.

I don't know if some "channel" troughing supported on stakes contained asbestos - but a form of thin walled concrete looking trough was tried for a time. There have also be plastic and fibreglass efforts. I can't recall seeing much metal troughing - except sometimes around under bridges where extra strength is needed.

The current concrete trough catalogues show no reduction in the standard sizes of standard units of troughing - which is only logical - the system has been in place for a few decades now... Which raises the question of when it first appeared?

In some places there is still a fair quantity of wooden troughing (3 equal planks formed to a square U) with a fourth plank for the lid - all on support legs - sometimes wood or steel instead of more wood.

Perhaps we can conclude that the green pipe on the surface is only another attempt to find a solution?

"Trip hazards" in cesses? there's junk all over the place - including (in my bruised experience) on so called "safe cesses". My particular favourite was when people dug holes in safe cesses - and didn't mark them.

There is a reason why railwaymen walk looking at the ground.

:-x
 

LAX54

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Troughing...prime location for rats and the like, who are partial to a nibble here, and a nibble there, and being enclosed, warm, quiet and undisturbed !
 

carriageline

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It surprises me the railway doesn't use something to the blown fibre system that BT use.

Which is essentially a tube with lots of holes in it, and using compressed air they blow wires/cables down the tubes.

Only time it needs "lifting" is when it is installed, and installing further cables is easier. It can also be buried hidden, with occasional man holes at set distances.

How easier it is to install cables the sort of lengths they require I don't know, or whether the initial outlay would be worth the cost, but it would certainly improve things when installing future cables


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D Foster

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Troughing...prime location for rats and the like, who are partial to a nibble here, and a nibble there, and being enclosed, warm, quiet and undisturbed !

A couple of years back I saw troughing that had been "filled-in" with giant sized and very long "bottle brush" that was dark red-oxide in colour. I assumed that this was to keep vermin out - and cats. I have a picture of a cat emerging from troughing at Rock ferry - it had probably popped in for a snack.

Perhaps with nice new work like the Borders Railway the blown system is relatively easy and cheap. Much of the time the railway is working with a live system. Even with possessions any cabling often has to be down between or alongside other jobs going on. Perhaps the blown system would be installed during a blockade in future?

Meanwhile, back at the OP... It occurs to me that troughing routes are "cables laid along the cess"... And much bigger than the green stuff! We've just got used to it.
I wonder what the various track staff made of its appearance in the cess when it first replaced those nice old-fashioned telegraph poles and overhead copper cable (that got stolen).
Incidentally - looking at the handling and risk issues - unless they got lucky and could get a ballast train to dump out their new poles the S&T had to manually carry poles out to site. This would involve the gang carrying the pole on their shoulders. It probably happened "between trains" to a fair extent.
The poles were stepped by hand as well - no nice, convenient, Hiabs on power trolleys or RoadRailers and cranes would be a major luxury. The energy for drawing the copper wires up and along the pole line also came from human muscles.

:)
 

randyrippley

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I remember an overnight snow storm in around 1982/83 which felled just about every railway telegraph pole between Yeovil and Salisbury. Within about 2 days BR had a "temporary" cable lying on the surface alongside the track connecting up the signals. Real cable, not glass fibre. That "temporary" solution lasted around 10-15 years before the signals were finally upgraded
 

Hellzapoppin

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I remember that very well, in fact I was one of the staff who installed the temp cable and jointed it through. Bl##dy cold it was too, we had to warm the insulating tape up with our gas torches as it was too cold to use. We used every bit of temp cable we could get our hands on, I can remember the poles being snapped off due to the weight of ice and the high winds on the wires. Happy days !!
 

ryan125hst

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Interesting stuff guys! I never realised that it was so difficult to install and maintain the cables in the troughs for one thing, and just how much of an issue rats and cats getting in them can be for another. I guess what cables and troughing are installed is always some compromise between cost, durability, ease of access and robustness.

And that was quick work laying the temporary cable, particularly given how long it lasted!
 

Hellzapoppin

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Thanks Ryan. Trough routes are probably the best compromise although they are expensive to install hence the use of DISAC in some areas. Blown fibre may seem like a good idea however you have to install the duct first, in which case why not install a fibre optic cable in the first place. The bottle brushes were used to try and keep sharp toothed critters out of the troughs and so was filling them with sand. I've seen all sorts in the troughs, toads, frogs, lizards, snakes, rabbits, thousands of ants nests, weasels, stoats and even a fox. Incidentally, the DISAC is anchored ever 20-30 metres to stop it being dragged into the track but I agree it can look messy.
 

68000

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Blown fibre may seem like a good idea however you have to install the duct first, in which case why not install a fibre optic cable in the first place

Future proof, when FTN was installed, the standard fibre was 24 fibre, now it is 48 fibre. With the blown fibre solution, you install what you need now and 'blow in' extra in later years without the need to refurbish or upgrade the route or install a new cable. It is much quicker to install as well
 
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