GWML Electification

[Coryton]

At the risk of going off-topic, my take (as an outsider with some subject knowledge but no inside information) is that a lot of the Edinburgh problems were underground utilities not geology as such.  There was a major dispute between the civils contractor and the client about payment for work allegedly outside the original scope.  This may suggest that the client went for the cheapest who are often the ones that submit a low price aiming to make their money on variations when unforeseen items turn up that the client has no practical alternative but to pay for. 

 

 

I do find the way these things work rather strange (though I don't know how I'd improve matters).

 

A contract like that will go through a very thorough tendering process to (attempt to) ensure value for money.

 

But once the contract is awarded, when the contract change notes start coming in it's a very different story - you can't easily go elsewhere at that point so how do you ensure you continue to get value for money? (Answer - so far as I can see - you don't).

[St. Simon]

But once the contract is awarded, when the contract change notes start coming in it's a very different story - you can't easily go elsewhere at that point so how do you ensure you continue to get value for money? (Answer - so far as I can see - you don't).

It's upto the project team to ensure that value for money is maintained, this is particularly done in NR as I have been seen in some of my projects as we must demonstrate value for public money.

 

There's a lot that happens behind the scenes on projects that the public doesn't see.

 

Simon

[SwissRailPassion]

There's so much complexity to this. The DfT did not specify 140 mph at first but a little later. Thus the catenary design had to be adjusted. Two pantographs raised on 5 + 5 services causes more stress and movement so the system needs to be robust, this too was not apparent at the start. The DfT moved the goalposts which added to the costs and made things much harder to control. Add to this cabling, bridge work, piles deeper than a dockyard, a whizz bang magic installation train that was incorrectly specified, engineers unused to large project electrification, a functioning busy mainline, Crossrail overlap, and Reading station rebuilding and there's a lot that can go wrong.

 

If the DfT had authorised a few infill schemes technical expertise could have been built up over time and good practice developed. However that's never the way with Whitehall.

[Siberian Snooper]

Not only DfT that shift goal posts, MoD does as well, that always pushes the overall cost up of any project regardless of size and they'd like it in the same time frame, so that you get an overtime premium as well.

[jonathan452]

FYI - Alstom launches Clever cantilever for UK railway electrification - 12th May 2017

 

http://www.railengineer.uk/2017/05/12/alstom-launch-clever-cantilever-for-uk-railway-electrification/

Edited May 13, 2017 by jonathan452

[The Stationmaster]

I grew up in Maidenhead and used the station regularly in the 90s so this is quite interesting. At one point there was a proposal to double-track the bay. Is that going ahead or do 5A and 5B simply represent the existing platform being notionally divided half-way along to separate terminating mainline services from those on the branch (which I think happened anyway in the 90s).

 

Do you have any pictures of the slow and branch platforms as I would be interested to see how much they have changed with the work.

 

5A & 5B are simply a split somewhere in the length of the branch bay (which is of course a through line).  I am thinking of popping up there to take some pics as I haven't taken any at Maidenhead since just before the original MAS was commissioned back in the 1960s so  I really ought to get up to date.  The original canopies have mostly gone and have been replaced by some appalling looking things which are probably as ineffective as they look - quite why that has happened I don't know but at least at Twyford the existing canopies are simply being cut back and the full woodwork will hopefully be reinstated - at some other stations east of Maidenhead there doesn't even seem to be any cutting back!

 

Incidentally the original footbridge is still in position at Taplow but is boarded up to prevent use although I noticed a couple of orange clad persons 'doing something' on it yesterday so I wonder if it will be reinstated after some sort of testing?  Similarly the old footbridge at Slough is still there and in use and there are also a couple of brick arch overbridges which have not been altered at all so presumably offer sufficient clearance  (that is what is also going to happen on the Relief Lines at Twyford I believe).

 

A small update - all platforms lines at Reading except No.10 now have catenary in place, there is a catenary wire only on Platform 10.  This doesn't of course mean the catenary is usable because apart from not being connected to a power supply various temporary lashings are still visible in places and at least one contact wire is attached to a steel structure without any sort of intervening insulator.

[The Stationmaster]

FYI - Alstom launches Clever cantilever for UK railway electrification - 12th May 2017

 

http://www.railengineer.uk/2017/05/12/alstom-launch-clever-cantilever-for-uk-railway-electrification/

It doesn't look very 'clever' to me compared with the kit being used on the GWML which only needs one insulator. only has a single point of attachment to the fitting from the boom/gantry  (with no need to drill the mast) - the attachment to a single line mast isn't much different and again only needs a single insulator.  (click on pics to enlarge)

 

 

[Peter Kazmierczak]

FYI - Alstom launches Clever cantilever for UK railway electrification - 12th May 2017

 

http://www.railengineer.uk/2017/05/12/alstom-launch-clever-cantilever-for-uk-railway-electrification/

Wonder if they'll do it in OO?

 

Just watched the Alstom video a couple of times. Towards the end does the guy say they'll be two variations of CLever and that the one illustrated is for line speeds of 100mph and below? Slightly confused here.....

Edited May 13, 2017 by Peter Kazmierczak

[ejstubbs]

At the risk of going off-topic, my take (as an outsider with some subject knowledge but no inside information) is that a lot of the Edinburgh problems were underground utilities not geology as such.

 

Indeed, I thought I made that clear in the reference to "digging large trenches down 200-plus-year-old streets and being surprised at finding unexpected stuff down there".  I said the issues with GWML electrification echoed the Edinburgh trams in that sense - meaning that stuff that couldn't be surveyed or otherwise accurately costed at the outset was not properly accounted for in the project plan (budget & schedule) as tendered.

Edited May 13, 2017 by ejstubbs

[Hellzapoppin]

Unexpected stuff isn't a true statement to be honest, trial holes were and still are excavated and these should highlight any issues.

The problems with the project are many and each one has an impact on production and as yet I've seen no definitive answer to these and I don't think I will.

[jim.snowdon]

Edinburgh's problem was finding and working out where the Utilities went. From my experience with the Croydon Tramlink project, until the New Roads & Streetworks Act obliged Utility companies to record where there apparatus was when it was laid or altered, the records could be distinctly sketchy. Even after NR&SWA, the generally accepted view was that they were accurate to the nearest street. The contractual problem is when the number and nature of Utilities apparatus being found found exceeds even the risk factor that would have been allowed for in pricing the contract. On top of that, the whole situation was not helped by variations in the exchange rates working against the contractor.

 

For Great Western, the unknowns in this context are almost entirely confined to railway apparatus, and it was common knowledge that the Western Region had buried their signal cables where others would have laid trough route. It should not have been difficult to put two and two together and question why there were no trough routes full of cables. If nothing else, I would have expected the early stages of the Thames Valley resignalling project to have thrown that up when equipment was being decommissioned. The real showstopper would appear to have been the piling, if only that the problems over driving the piles and the rate of installation were painfully obvious (and audible). By no means all of the issues can be blamed on the state of the earthworks, given the variations in topography along the line. It would be hard to believe that the sheer depth of the piles was not a significant factor, and to me it is still a good question as to why these piles had to be so deep in comparison to OLE foundations across other parts of the electrified network. It all has a feel of excessive conservatism in the design, something that is reflected in the steelwork that has been planted on top of said piles. The general technique before tubular piles became flavour of the month was for the foundations to be augered to nothing like the same depth and concreted in situ. So far, there are no signs of either the Liverpool/Manchester or Southend OLE wanting to fall down after over half a century in service, and some of the ground conditions on the LT&S are none too friendly, given that it is built alongside the Thames Estuary.

 

Jim

[phil-b259]

So far, there are no signs of either the Liverpool/Manchester or Southend OLE wanting to fall down after over half a century in service, and some of the ground conditions on the LT&S are none too friendly, given that it is built alongside the Thames Estuary.

 

Jim

 

This may be true - but the LTS system does not have to cope with 140mph running and although there are sections of the WCMl where 130 is achieved by Pendalinos, this is with only a single pantograph deployed rather than the two required for IEPs operating in multiple.

 

Its also true, that having been 'stung' by OLE problems on the ECML there was a deep desire within NR not to make the same mistake by going for a minimal 'well it will just about cope solution', particularly as OLE stuff can be very awkward to upgrade if certain methods are employed (e.g. headspans where all lines are affected rather than just one). As such going or a slightly 'over engineered' solution now is understandable in principle.

[jim.snowdon]

This may be true - but the LTS system does not have to cope with 140mph running and although there are sections of the WCMl where 130 is achieved by Pendalinos, this is with only a single pantograph deployed rather than the two required for IEPs operating in multiple.

 

Its also true, that having been 'stung' by OLE problems on the ECML there was a deep desire within NR not to make the same mistake by going for a minimal 'well it will just about cope solution', particularly as OLE stuff can be very awkward to upgrade if certain methods are employed (e.g. headspans where all lines are affected rather than just one). As such going or a slightly 'over engineered' solution now is understandable in principle.

Maybe, but the number of pantographs per train and speed has more to do with the design of the contact wire and its suspension than it does about the size of the masts and their foundations. Wire tension does have an effect on them but the GW masts are still over engineered by comparison with anything else. What I understand the ECML as suffering from is not any failing of the support structures but dewirements that have more to do with the contact system itself. It is worth comparing the GW wiring with that of the French high speed lines, where train speeds are higher still and trains are frequently two units, giving two pantographs per train.

 

Jim

[Edwin_m]

I do find the way these things work rather strange (though I don't know how I'd improve matters).

 

A contract like that will go through a very thorough tendering process to (attempt to) ensure value for money.

 

But once the contract is awarded, when the contract change notes start coming in it's a very different story - you can't easily go elsewhere at that point so how do you ensure you continue to get value for money? (Answer - so far as I can see - you don't).

There ought to be clauses in the contract that cover this, for example extra work outwith the original scope would have to be agreed beforehand and prices based on agreed hourly rates.  The devil is in the detail and in whether one or both sides tries to game the system - but I repeat I have no inside knowledge of what actually happened in Edinburgh. 

[Coryton]

There ought to be clauses in the contract that cover this, for example extra work outwith the original scope would have to be agreed beforehand and prices based on agreed hourly rates.  The devil is in the detail and in whether one or both sides tries to game the system - but I repeat I have no inside knowledge of what actually happened in Edinburgh. 

 

I'm not sure I'd say the problem is just in the details.

 

Hourly rates can be agreed in advance, but what you can't always agree is how many hours are involved.

 

This isn't a problem in the initial contract because bidders have to keep costs low to win. But once you're into contract changes, if it's not obvious how much work a change involves (say it involves analysis work, or computer programming, rather than something like building an extra wall) it becomes very difficult.

[Coryton]

This may be true - but the LTS system does not have to cope with 140mph running and although there are sections of the WCMl where 130 is achieved by Pendalinos, this is with only a single pantograph deployed rather than the two required for IEPs operating in multiple.

 

 

Are they supposed to reach 130? I thought anything about 125 required cab signalling.

 

 and to me it is still a good question as to why these piles had to be so deep in comparison to OLE foundations across other parts of the electrified network. It all has a feel of excessive conservatism in the design, something that is reflected in the steelwork that has been planted on top of said piles. The general technique before tubular piles became flavour of the month was for the foundations to be augered to nothing like the same depth and concreted in situ. So far, there are no signs of either the Liverpool/Manchester or Southend OLE wanting to fall down after over half a century in service, and some of the ground conditions on the LT&S are none too friendly, given that it is built alongside the Thames Estuary

 

I think I read some time ago in Modern Railways that it was as simple as someone doing their sums wrong and calculating much greater pile depths than actually required.

 

If so, a rather expensive mistake.

[jim.snowdon]

The limit for Pendolinos, and anything else on the WCML, is 125mph, however whilst they may be batting about at that speed on one pantograph, there are 8- and 12-car sets of 350s doing up to 110mph on 2 / 3 pantographs, and all that on 1960s/1970s OLE.

 

The second and subsequent pantographs will always get a rougher ride and observation of the higher speed stock shows the effort going into improving the ability of the bow to follow the movements of the contact wire independently of the main frame.

 

Jim

[jim.snowdon]

Are they supposed to reach 130? I thought anything about 125 required cab signalling.

 

 

 

I think I read some time ago in Modern Railways that it was as simple as someone doing their sums wrong and calculating much greater pile depths than actually required.

 

If so, a rather expensive mistake.

You would like to think that a more experienced engineer in the design office would spot such an error before it got to the customer. But, a problem of the modern age is designer's dependence on computer software without the common sense experience to spot when duff input data is resulting in duff output. A case of "computer says....". Add to that that with modern procurement policies project engineers will not generally challenge over engineering - as long as the design meets the standards it gets approval.

 

Jim

[jjb1970]

Do railway companies use external independent bodies to review and verify their design calculations? In marine it is a statutory requirement under SOLAS for ship designs (hence classification societies). At one time if a shipyard engineer or engine builder equivalent had a document returned from class as not accepted and told to do it again they'd be in serious trouble as it was considered a humiliation for the company. When I did engine and shaft line design approvals in class it was worrying how many errors got through all the yard and engine processes and my feeling was they'd decided it was cheaper to use class as a QC check than to do it themselves. Either way, a robust check of calculations is essential.

[Edwin_m]

Anything safety related on the railway has to go through some form of independent assessment.  But they will be looking at whether the design is safe rather than whether it is optimum for purpose, so (arguably) over-engineered designs won't get picked up. 

[RJS1977]

On the other hand, Brunel, Stephenson etc over engineered their railways too (for the most part), which is why they're now able to carry far faster, heavier and more frequent trains than they carried in the mid-19th Century.

[The Stationmaster]

Edinburgh's problem was finding and working out where the Utilities went. From my experience with the Croydon Tramlink project, until the New Roads & Streetworks Act obliged Utility companies to record where there apparatus was when it was laid or altered, the records could be distinctly sketchy. Even after NR&SWA, the generally accepted view was that they were accurate to the nearest street. The contractual problem is when the number and nature of Utilities apparatus being found found exceeds even the risk factor that would have been allowed for in pricing the contract. On top of that, the whole situation was not helped by variations in the exchange rates working against the contractor.

 

For Great Western, the unknowns in this context are almost entirely confined to railway apparatus, and it was common knowledge that the Western Region had buried their signal cables where others would have laid trough route. It should not have been difficult to put two and two together and question why there were no trough routes full of cables. If nothing else, I would have expected the early stages of the Thames Valley resignalling project to have thrown that up when equipment was being decommissioned. The real showstopper would appear to have been the piling, if only that the problems over driving the piles and the rate of installation were painfully obvious (and audible). By no means all of the issues can be blamed on the state of the earthworks, given the variations in topography along the line. It would be hard to believe that the sheer depth of the piles was not a significant factor, and to me it is still a good question as to why these piles had to be so deep in comparison to OLE foundations across other parts of the electrified network. It all has a feel of excessive conservatism in the design, something that is reflected in the steelwork that has been planted on top of said piles. The general technique before tubular piles became flavour of the month was for the foundations to be augered to nothing like the same depth and concreted in situ. So far, there are no signs of either the Liverpool/Manchester or Southend OLE wanting to fall down after over half a century in service, and some of the ground conditions on the LT&S are none too friendly, given that it is built alongside the Thames Estuary.

 

Jim

 

Virtually all the signalling cable in the London Division resignalling schemes was either in concrete troughing or (in older work and routes which were retained east of Acton) carried on lineside cable supports in a  similar fashion to the method widely used on the London UndergrounD network.  Some of the buried cable put in during the early 1960s schemes was  in metal piping (cast iron?) such as went in at Twyford station on the Down Main platform and elsewhere.  And all the underground routes were marked with concrete cable route markers - which all seem to have vanished over the years

 

However the problem with the concrete troughing was that as ballast levels were raised to ensure deep ballasting for cwr plus associated blanketing works to keep the Thames Valley clay beneath the formation to there was a lot of ballast cleaning with the spoil being dumped at the lineside plus the cess paths where much of the troughing was simply vanished underneath the ever rising and spreading mountains of ballast.  Now that the lineside vegetation has been tackled - and before it grows again - it is very easy to see in some places the area where ballast cleaning spoil was dumped as it changed the topography of the lineside.  Some large cable routes - in some cases two or three parallel lines of concrete troughing have simply vanished over the years but were still very much in use.

 

And in fact according to some reports there actually weren't many instances of piling going through cable routes.

 

The depth issue is another matter and while there is one spot where adjustable structures have been used due to the ground conditions the aim elsewhere seems to have been to sink the piles far enough down to reach solid ground or use much larger diameter concrete filled (and in some cases concrete 'collared' base piles).  Presumably the aim is structural integrity but don't overlook the original 'standard' pile depth which seems to have been found inadequate in places.  the other problem  - although unreported as far as I'm aware - will have been the piles going in and hitting the concrete grouting in many of the Thames Valley (in particular) embankments - something which should have been foreseen with proper forethought and investigation.  Interestingly far more variety in piling methods seems to have emerged since the project hired in a retired WR civil engineer with good knowledge of ground conditions on most the route being electrified.

[The Stationmaster]

Do railway companies use external independent bodies to review and verify their design calculations? In marine it is a statutory requirement under SOLAS for ship designs (hence classification societies). At one time if a shipyard engineer or engine builder equivalent had a document returned from class as not accepted and told to do it again they'd be in serious trouble as it was considered a humiliation for the company. When I did engine and shaft line design approvals in class it was worrying how many errors got through all the yard and engine processes and my feeling was they'd decided it was cheaper to use class as a QC check than to do it themselves. Either way, a robust check of calculations is essential.

It was definitely a requirement in respect of rolling stock design following privatisation where independent safety assessment was introduced - using an approved outside body to do the assessing (I caught out Serco on two rolling stock projects while doing such work, oddly one of them was for Hitachi).  As far as infrastructure work is concerned it is basically subjected to NoBo (Notified Body) assessment and approval but I doubt that goes down to detail design of every single hole in the ground otherwise GWML electrification would be taking even longer.

[Peter Kazmierczak]

Mike,

Thought your final sentence was going to end with "forever"..........

[D1059]

Just been sent this by a contact who has said it is OK to post here. The letter has been sent to several local/national newspapers and rail magazines

 

 

 

  

Edited May 17, 2017 by D1059