Great Western Electrification Progress

[Philip Phlopp]

And other electrification schemes shouldn't have to contend with the BR Western Region legacy of buried, unmapped signal cables, which has been one of the key problems along the GWML.

And the cables which weren't buried and hidden started to suffer from internal failures when piling started - that's arguably worse than a clean break as they can cause more transient faults which are harder to pinpoint.

 

[Hellzapoppin]

Who says they aren't mapped ?

 

[YorkshireBear]

Have you missed Network Rail's PR offensive in just about any publication that moves in recent weeks saying that they have indeed learned lessons?

And other electrification schemes shouldn't have to contend with the BR Western Region legacy of buried, unmapped signal cables, which has been one of the key problems along the GWML.

Lots of steelwork now in place at Denchworth

http://hondawanderer.com/Recent_Additions.htm

No I haven't but as I work in the industry I have often seen Lessons Learnt and then also seen them repeat within months....

I hope lessons have actually been learnt.

 

[jimm]

Who says they aren't mapped ?

The chief executive of Network Rail.

http://www.railjournal.com/index.ph...electrification-costs-set-to-reach-£25bn.html

"Construction has been very much more complex than it should have been, and that was partly down to planning," he explains. "Normally you would carry out resignalling before electrification. Challenges in the signalling supply chain and construction sequencing meant we weren't able to do that in all cases, so we decided to start piling. Because the signalling cables were buried in the ballast in the1970s we didn't know exactly where they were, so we have cut through signal cables on two occasions during piling. This means that for every pile we now need to dig a trial hole."

Cable detection systems have been used in an attempt to overcome the problem, but Carne says that because cables are buried at depths of up to 1.2m these systems "have not proved sufficiently reliable." Furthermore, cabling location records are "not accurate" because they are relative to the position of the rail, which at many locations has moved over the last 40 years.

 

[po8crg]

Sounds like they are going through the gears in terms of progress now. Lets just hope there is a big folder somewhere called lessons learned. While some may call this electrification a disaster it will only be so if we do not learn from it and apply the lessons to every electrification in the country.

Not just this country! Balfour Beatty have just got the contract to electrify the CalTrain line into San Francisco.

 

[nlogax]

Not just this country! Balfour Beatty have just got the contract to electrify the CalTrain line into San Francisco.

These projects go back years. Balfour Beatty also electrified the northern end of the Northeast Corridor in the US and that was twenty years ago. Who's keeping this 'Big Book of Learned Lessons'..?

 

[Tio Terry]

And the cables which weren't buried and hidden started to suffer from internal failures when piling started - that's arguably worse than a clean break as they can cause more transient faults which are harder to pinpoint.

There's a bit more to it than that.

The design of the signalling systems that were installed along with the signalling in the 1970's included "single cut" circuitry, this, in effect, used common return instead of switched return. Later systems used "double cut" designs which are far more reliable. So, if a cable became damaged, cores within the cable could become livened erroneously and, with common return, could lead to wrong side signalling failures. A similar, but not identical, situation to Clapham Junction. A false feed could result in a proceed signal indication when it should be at red.

 

[Hellzapoppin]

The chief executive of Network Rail.

http://www.railjournal.com/index.ph...electrification-costs-set-to-reach-£25bn.html

What he does say is that the available information is not reliable enough not that there are no drawings available.
The trial holes need to be excavated regardless as they are used to check a position is clear to pile, this includes checking for obstructions, old track drains, old culverts, voids etc etc as well as to see the type of ground.
I was with a team yesterday who dug down 300mm and hit bedrock, this info will now be passed back for a review of the type of foundation. Finally its the safe thing to do, railway services aren't the only things running close to the track.

 

[jimm]

What he does say is that the available information is not reliable enough not that there are no drawings available.
The trial holes need to be excavated regardless as they are used to check a position is clear to pile, this includes checking for obstructions, old track drains, old culverts, voids etc etc as well as to see the type of ground.
I was with a team yesterday who dug down 300mm and hit bedrock, this info will now be passed back for a review of the type of foundation. Finally its the safe thing to do, railway services aren't the only things running close to the track.

If you want to play semantics, that's up to you.

The key fact of the matter is that they don't accurately know where a lot of the cables are, even if some sort of records may exist from way back when, but these cannot be relied upon, as Mr Carne made clear to the MPs. With the net result that piling has been far slower than projected, etc, etc.

I somehow doubt that when they were planning the things like the factory train that they expected men with shovels would have to go out and dig 15,000 to 20,000 holes before the technology could do its stuff.

 

[SpacePhoenix]

Is it just the GWR where they don't know the location of the cables or is it a common problem all over the network?

 

[Tio Terry]

Is it just the GWR where they don't know the location of the cables or is it a common problem all over the network?

Western had a policy of direct burial of S&T cables. Most BR Regions utilised concrete troughing or something similar so the location is generally known. Of course, there will be instances where the trough route has become buried but that will probably be for relatively short distances.

During the 1970's a lot of cable was buried by rail mounted Mole Plough, East Anglia has quite a bit, so if it comes to electrifying any of those routes then the same problem will exist. Peterborough-March-Ely, Ely-Chippenham Junction and Cambridge-Haughley Junction, Ipswich- Felixstowe, Norwich-Yarmouth/Lowestoft and Norwich-Ely all have considerable amounts of Mole Ploughed cable. I'm sure there are other areas where this method of cable laying was used.

 

[HowardGWR]

At Bath station western end skew bridge over the Avon, the orange men on pontoons were doing work on one of the abutments in the water. I wondered whether this was electrification work and whether it's planned to fix the overhead gantries to these, as opposed to cantilevering them from the bridge.

 

[Hellzapoppin]

If you want to play semantics, that's up to you.

The key fact of the matter is that they don't accurately know where a lot of the cables are, even if some sort of records may exist from way back when, but these cannot be relied upon, as Mr Carne made clear to the MPs. With the net result that piling has been far slower than projected, etc, etc.

I somehow doubt that when they were planning the things like the factory train that they expected men with shovels would have to go out and dig 15,000 to 20,000 holes before the technology could do its stuff.

Actually Jimm it was. Health and Safety legislation and NRs own standards are quite specific and trial holes are to be used to confirm the location and condition of buried services regardless of having detailed drawings or not.The Pangbourne cable strike cost millions and that is unsustainable. As for trial holes holding up the programme well that's not the case anymore. The lads in Wales are trialling alternative methods of excavation which avoids men on shovels and that's proving positive so far.
--- old post above --- --- new post below ---

Actually Jimm it was. Health and Safety legislation and NRs own standards are quite specific and trial holes are to be used to confirm the location and condition of buried services regardless of having detailed drawings or not.The Pangbourne cable strike cost millions and that is unsustainable. As for trial holes holding up the programme well that's not the case anymore. The lads in Wales are trialling alternative methods of excavation which avoids men on shovels and that's proving positive so far.

http://www.youtube.com/watch?v=RSCz-35M9hA&sns=em

Hope this link shows correctly but this is what happens if you're not careful and don't follow the rules.

 

[Mintona]

I forgot to post on Thursday afternoon as I was a little busy, but I had a trip over to Cardiff around lunchtime. The Severn Tunnel now has brackets attached to the roof for almost the entire length on both the up and down sides. There are also more piles installed to the west of Severn Tunnel Jn station. As previously noted there are now masts alongside the up main at Llanwern, and more installed alongside the down relief. And finally between Ebbw Jn and Marshfield (Newport and Cardiff) a decent amount of masts were laying alongside piles in the downside cess, which can only assume had been left ready to install this weekend.

I believe I have another trip over Monday morning so should be able to provide a further update of the weekend's work then.

 

[jimm]

Actually Jimm it was. Health and Safety legislation and NRs own standards are quite specific and trial holes are to be used to confirm the location and condition of buried services regardless of having detailed drawings or not.The Pangbourne cable strike cost millions and that is unsustainable. As for trial holes holding up the programme well that's not the case anymore. The lads in Wales are trialling alternative methods of excavation which avoids men on shovels and that's proving positive so far.

I'll take your word for it, though if it was always planned to dig all these holes anyway, one might ask why the electrification programme isn't on schedule? And yes, I know trial pits are not a guarantee of anything, that cables are at random depths, etc.

Even if you don't like the word unmapped, the records of buried signal cable locations are not detailed, accurate or reliable, which has not assisted matters when it comes to piling work, as people like Mark Carne and Sir Peter Hendy have made very clear, on a number of occasions.

Unless I'm missing something, South Wales has been resignalled recently, without buried cables, which presumably means there are likely to be rather fewer piling locations where buried services might be present in the first place. If new methods are speeding up the process there, great.

 

[Philip Phlopp]

I'll take your word for it, though if it was always planned to dig all these holes anyway, one might ask why the electrification programme isn't on schedule? And yes, I know trial pits are not a guarantee of anything, that cables are at random depths, etc.

Even if you don't like the word unmapped, the records of buried signal cable locations are not detailed, accurate or reliable, which has not assisted matters when it comes to piling work, as people like Mark Carne and Sir Peter Hendy have made very clear, on a number of occasions.

Unless I'm missing something, South Wales has been resignalled recently, without buried cables, which presumably means there are likely to be rather fewer piling locations where buried services might be present in the first place. If new methods are speeding up the process there, great.

It's the disadvantage of piled foundations. The use of poured concrete foundations would have eliminated most of these issues, but H&S makes the type of lineside excavation and concrete pouring that went on during the ECML electrification difficult to achieve.

The lack of experience in electrification has been the biggest problem, combined with switching from using the techniques and access arrangements in place for the ECML, the only thing that's the same as ECML electrification is running the contact wires, really, almost everything else is different and new.

 

[Tio Terry]

The original plan was to relock and recable the signalling and comms systems before starting to pile mast foundations with cables in clearly visible concrete troughing. But lack of competent signalling resource meant that the signalling works were delayed. The decision to go ahead with piling quickly proved to be the wrong one with a number of cable strikes causing some major delays. There was never any intention to hand dig for each pile, which is what they have had to do, so the time and cost have increased quite dramatically.

 

[LNW-GW Joint]

Unless I'm missing something, South Wales has been resignalled recently, without buried cables, which presumably means there are likely to be rather fewer piling locations where buried services might be present in the first place. If new methods are speeding up the process there, great.

Resignalling has been completed Patchway-Cardiff East, so there shouldn't be any cable problems there.
Cardiff resignalling (Central and West) is still in progress, completing over Christmas/New Year.
Port Talbot West, completing resignalling to Swansea, will be 2018, but that shouldn't affect the electrification programme.

 

[edwin_m]

It's the disadvantage of piled foundations. The use of poured concrete foundations would have eliminated most of these issues, but H&S makes the type of lineside excavation and concrete pouring that went on during the ECML electrification difficult to achieve.

Isn't the hole for a concrete foundation dug with some kind of auger, and wouldn't that be just as likely to damage any buried cables as a pile would?

 

[Philip Phlopp]

Isn't the hole for a concrete foundation dug with some kind of auger, and wouldn't that be just as likely to damage any buried cables as a pile would?

It is now, it wasn't then.

http://www.railforums.co.uk/showthread.php?t=54804

Dug out foundations with a polystyrene former. It would need a good digger operator and team to be paying attention for wires, but they were generally good at it, of course the route was widely re-signalled for electrification and was ready to go, so less of an issue anyway.

 

[edwin_m]

It is now, it wasn't then.

http://www.railforums.co.uk/showthread.php?t=54804

Dug out foundations with a polystyrene former. It would need a good digger operator and team to be paying attention for wires, but they were generally good at it, of course the route was widely re-signalled for electrification and was ready to go, so less of an issue anyway.

Thanks for that. It surprises me that a digger could make a hole that deep and that narrow, but they obviously did so.

I seem to remember some sort of solvent was poured over the former after the concrete set and it effectively disappeared leaving a square hole for the mast. This is probably considered a hazard these days, so may be why they now have threads cast in for bolting the mast instead?

 

[McRhu]

I seem to remember some sort of solvent was poured over the former after the concrete set and it effectively disappeared leaving a square hole for the mast. This is probably considered a hazard these days, so may be why they now have threads cast in for bolting the mast instead?

Petrol was used to dissolve the polystyrene, at least when conditions were wet apparently. As regards digging the hole for the masts, augers were indeed used, at least on the Glasgow North Suburban Electrification of the early 1960s. Apologies for temporarily sending this thread off topic by about 400 miles, but here's a link (see 18th page down in PDF).

http://www.railwaysarchive.co.uk/documents/BRS_Glasgow1960.pdf

 

[Mintona]

I can confirm that there are now 29 masts installed in the Llanwern West area, and a further 14 (all alongside the down relief) between Pheasant's Curve and Marshfield. These are the first ones to be installed between Newport and Cardiff.

 

[CapitalStar378]

On the train from Cardiff to Didcot on Sunday I didn't see any sign of even piling on most of the line after Bristol. Seems strange to be doing south Wales ahead of the middle section.

 

[LNW-GW Joint]

On the train from Cardiff to Didcot on Sunday I didn't see any sign of even piling on most of the line after Bristol. Seems strange to be doing south Wales ahead of the middle section.

The signalling area of Bristol PSB has not been upgraded yet, so piling is not being done to avoid the buried cable problem.
Some piling has been done at the Wootton Bassett end, which has been resignalled .
The signalling west of Patchway has been upgraded so they are able to do the piling.
I think it is a different set of resources doing the work, too.

 

[HowardGWR]

The signalling area of Bristol PSB has not been upgraded yet, so piling is not being done to avoid the buried cable problem.
Some piling has been done at the Wootton Bassett end, which has been resignalled .
The signalling west of Patchway has been upgraded so they are able to do the piling.
I think it is a different set of resources doing the work, too.

I can't wait to see the back of the Bristol PSB. It sums up all the frustration at the 70s retrenchment consequences that blocked off the terminus side of Bristol TM. A bit off topic but these schemes are totally interlocked as LNW-GW_Joint's post demonstrates.

 

[Andrewlong]

On the train from Cardiff to Didcot on Sunday I didn't see any sign of even piling on most of the line after Bristol. Seems strange to be doing south Wales ahead of the middle section.

Same thing in Thames Valley. Tilehurst to Didcot completed before say Reading to Maidenhead. I am sure someone in the know will explain.

 

[swt_passenger]

Same thing in Thames Valley. Tilehurst to Didcot completed before say Reading to Maidenhead. I am sure someone in the know will explain.

Tilehurst to Didcot was always planned to be the advance area for wiring for use as an IET (class 800 series) test track. That's about it. Otherwise sections such as Maidenhead to Reading come under a different contractor, because at some stage the contract areas of responsibility were split.

 

[HowardGWR]

Tilehurst to Didcot was always planned to be the advance area for wiring for use as an IET (class 800 series) test track. That's about it. Otherwise sections such as Maidenhead to Reading come under a different contractor, because at some stage the contract areas of responsibility were split.

On the subject of the first stretch, while visiting a friend in Goring the other day, I was told that they get station announcements warning not to raise umbrellas! My friend wondered how pax on WCML and ECML have survived all these years, without. GWR (as FGW) have, in the past had to apologise for stupid announcements.

 

[swt_passenger]

On the subject of the first stretch, while visiting a friend in Goring the other day, I was told that they get station announcements warning not to raise umbrellas!

Was discussed in this thread a couple of weeks back. Who knows what announcements were made immediatley prior to switch on with the WCML and ECML schemes. I recall some sort of news media safety campaign at the time, but cannot remember any posters or announcements made.

AIUI the safety distances are calculated to include the possibility of people raising umbrellas.