GWML Electification

[jyte]

BTW as they appear to be useless I shall stop posting updates on this thread.

 

The reason I created an account here (a month or so ago) was actually to thank you for the reports you were putting together - I just never got around to it. 

 

I really appreciate (and I'm sure many others do too) the work you've done - I can right now only update the map every now and again and I do enjoy reading your updates. I certainly do not intend to replace the excellent work you do (I live on the wrong side of the country and lack the means to cover most of the GWEP personally). I only posted an asset that I had already created and was about a month old to help someone who wanted an overview of the situation. The reason I created the map is I'm quite a visual person and I appreciate being able to look at images rather than text.

 

I would personally really appreciate if you continued, as I am sure would many others.

[The Stationmaster]

Didcot stabling appears to have been put on the back burner (right at the very back in the darkest corner!) 

 

Interesting.  I did wonder quite why it was planned but as it sat there on the GANT chart right on the critical path I assumed it had been carefully thought about (maybe?).

[Hellzapoppin]

Well as my first post on here I'd just like to say Hello and just add a bit of info regarding the comments made about the tubes. The tubes are actually CHS piles, circular hollow section, and is 1 of 3 ways in which the foundations are constructed, the others being conventional,which is an augered hole fitted with a cage and filled with concrete and a bespoke foundation known as a gravity slab which is a big lump of concrete sitting on the ground which the mast bolts on. Hope this helps. LZ

[Hellzapoppin]

Years back a large amount of the bargeboarding on some of the station canopies at Reading was removed because it was rotten.  it was replaced by replicas made of fibreglass which then lasted until the rebuilding and I doubt if hardly anybody actually noticed that it wasn't timber.

 

The sidewalls on the new GW side platforms at Reading are all built very substantially in blue engineering brick and I expect the reason for using 'brick paper' (in plastic or fibreglass) at Bath is to save time while possibly having to meet some sort of local authority requirement because the use of brickwork in the time - and probably ground conditions - was simply a non-starter.  Judging by various past platform wall jobs I have seen done in either brick or blockwork it would have been well nigh impossible to complete one of the Bath platforms in a week using traditional materials.

The facade tiles are in fact ceramic and clip into the front of the EPs units, the coper units above are concrete. As you rightly say it would have been impossible to have done the upgrade using conventional methods plus the additional loading on the arches was too much. As a listed structure all the designs were scrutinized by everyone and their dog before work started, this was a massive undertaking trying to match engineering with consent.

[Mike Storey]

This may have been posted already, but in case not, it is well worth a read, on current electrification schemes' difficulties. This may help understand the problems also at GOBLIN and EGIP.

 

http://www.railengineer.uk/2017/02/24/egip-electrification-clearance-woes/

 

Of particular note is the claim that RSSB and British Standards (an entirely non-railway body) claimed that all concerned, including NR, had been fully consulted. But the removal of Appendix G (the most damaging aspect of the changes to the regulations) was a very late change, and NR are adamant that they were not consulted about that, which they would have absolutely resisted. The application of generic risk assessment was also dis-allowed by RSSB, citing, for reasons only known to them, that very detailed, site specific risk assessments were required for every location where 3.5m clearance would not be met economically. It also points out that the EU TSI regulations already allowed for schemes that were in an advanced state to be excluded from any new regulations, but that the UK bodies (particularly British Standards) were not amenable to this provision. There still appears to be no logical explanation as to why. Others with greater knowledge in this field may have the answer?

 

There remain criticisms surrounding how NR is managing the works on sites and the overall programmes across the UK (I have no idea of their validity, as I have no knowledge of the detailed programmes, methodologies, outstanding designs, geological survey content, contract breakdowns, and so on and on, so I have refrained from commenting much on this thread). But it is clear from the article (and other previous comments on here) that a common, and horrendously significant, impact has been from this one matter, even more beyond NR's control than we had been originally led to believe. I was not around during the WCML electrification, but those pointing to how smoothly the ECML version went, had better read up more about it. It was plagued by early cost projections, de-speccing, historic monument planning delays, track layout revisions post-design and some very difficult immunisation problems. Stringing up was only the final stage. For a better planned and executed scheme, look to the minor extension from Royston to Cambridge (in which I was involved). Simplicity itself, except that we could run even fewer trains afterwards than we could before, because budget constraints disallowed a power upgrade, only rectified a few years ago!

 

The only other useful comment I can make about the progress of piling, masting and wiring up, is this. If the original project inception dates back only to 2009, and included a decision to go for an entirely new form of OLE design as well, I cannot for the life of me understand how sufficient detailed ground surveying could have been undertaken in the time available, prior to design approvals and then methodology approvals. Given what people have said about the extreme variety in geological qualities, as well as man-made changes made over many decades (the records for which seem to have been lost in RT days), and the absence of comprehensive, intrusive surveys, across the entire route, the intermittent nature of foundation/piling work seems to be an inevitable consequence. My one major project, as SPM, on the Western involved just a handful of track miles on the original Filton Junction re-doubling scheme. Within that, we had one major landslip risk, despite intense pre-surveys, that arose only because the local CE had prior, personal knowledge, one sub-structure collapse, where we had no record of a sub-structure and Catscans had not been able to see this either, cables turning up where there was no record of cables nor trace of them during ground surveys, and a very serious error in the records regarding the sub-base construction of the original station, all of which we had to work around with decisions made on the hoof. We finished on time (bar some minor re-work), but it was a very close thing. I could not even be certain that the records of our work that we left behind were anything like 100% accurate, given the number of changes needed on site. I do not envy the GWEP programme teams' tasks, whatever their perceived competence right now! They are suffering from the lack of backbone of the people who liked to say yes, right at the start.

[bigP]

--

Edited January 31, 2021 by bigP
Deleted

[corneliuslundie]

That article is most interesting. However, it needs to be made clear that, unless specified in legislation (which applies only to  small minority), British Standards, whether purely British or British implementations of ENs, are voluntary standards. So the decision to follow the British National Foreword was a decision made by the RSSB and cannot be blamed on the BSI. In addition, there are standard periods for comment on draft British Standards, so I find it difficult to accept that there was no opportunity for Network Rail or anyone else involved to comment on the draft National Foreword. If it was added to the standard without a consultation period then its validity is suspect to say the least. In addition, Network Rail must have many members on the relevant BSI committee and must therefore have known well in advance of the consultation period what was proposed, and indeed should have been involved in the decision to publish it as a draft.

I must admit that I do not have the necessary technical expertise to make a judgement but I am surprised that a National Foreword should have been thought necessary as BSI and its representatives would have been involved in the drafting of the EN. Was the National Foreword perhaps initiated by the government?

I am not saying that RSSB did not make the appropriate decision on whether to adopt the standard, but the decision was made by that body not by BSI.

Jonathan David

Former Vice Chairman, British Standards Society

[The Stationmaster]

This may have been posted already, but in case not, it is well worth a read, on current electrification schemes' difficulties. This may help understand the problems also at GOBLIN and EGIP.

 

http://www.railengineer.uk/2017/02/24/egip-electrification-clearance-woes/

 

Of particular note is the claim that RSSB and British Standards (an entirely non-railway body) claimed that all concerned, including NR, had been fully consulted. But the removal of Appendix G (the most damaging aspect of the changes to the regulations) was a very late change, and NR are adamant that they were not consulted about that, which they would have absolutely resisted. The application of generic risk assessment was also dis-allowed by RSSB, citing, for reasons only known to them, that very detailed, site specific risk assessments were required for every location where 3.5m clearance would not be met economically. It also points out that the EU TSI regulations already allowed for schemes that were in an advanced state to be excluded from any new regulations, but that the UK bodies (particularly British Standards) were not amenable to this provision. There still appears to be no logical explanation as to why. Others with greater knowledge in this field may have the answer?

 

There remain criticisms surrounding how NR is managing the works on sites and the overall programmes across the UK (I have no idea of their validity, as I have no knowledge of the detailed programmes, methodologies, outstanding designs, geological survey content, contract breakdowns, and so on and on, so I have refrained from commenting much on this thread). But it is clear from the article (and other previous comments on here) that a common, and horrendously significant, impact has been from this one matter, even more beyond NR's control than we had been originally led to believe. I was not around during the WCML electrification, but those pointing to how smoothly the ECML version went, had better read up more about it. It was plagued by early cost projections, de-speccing, historic monument planning delays, track layout revisions post-design and some very difficult immunisation problems. Stringing up was only the final stage. For a better planned and executed scheme, look to the minor extension from Royston to Cambridge (in which I was involved). Simplicity itself, except that we could run even fewer trains afterwards than we could before, because budget constraints disallowed a power upgrade, only rectified a few years ago!

 

The only other useful comment I can make about the progress of piling, masting and wiring up, is this. If the original project inception dates back only to 2009, and included a decision to go for an entirely new form of OLE design as well, I cannot for the life of me understand how sufficient detailed ground surveying could have been undertaken in the time available, prior to design approvals and then methodology approvals. Given what people have said about the extreme variety in geological qualities, as well as man-made changes made over many decades (the records for which seem to have been lost in RT days), and the absence of comprehensive, intrusive surveys, across the entire route, the intermittent nature of foundation/piling work seems to be an inevitable consequence. My one major project, as SPM, on the Western involved just a handful of track miles on the original Filton Junction re-doubling scheme. Within that, we had one major landslip risk, despite intense pre-surveys, that arose only because the local CE had prior, personal knowledge, one sub-structure collapse, where we had no record of a sub-structure and Catscans had not been able to see this either, cables turning up where there was no record of cables nor trace of them during ground surveys, and a very serious error in the records regarding the sub-base construction of the original station, all of which we had to work around with decisions made on the hoof. We finished on time (bar some minor re-work), but it was a very close thing. I could not even be certain that the records of our work that we left behind were anything like 100% accurate, given the number of changes needed on site. I do not envy the GWEP programme teams' tasks, whatever their perceived competence right now! They are suffering from the lack of backbone of the people who liked to say yes, right at the start.

 

One thing which has been puzzling me is that some of the contact and catenary wire clearances from structures (and possibly platforms on curvature at Reading) look to be very much like the former BR arrangement rather than any new sort of standard.  The picture below is at Didcot and shows the catenary under a signal gantry structure - which we specified to be ohle clearance when it was designed back in 1992/93, i.e. it was designed to then current standards and not those of the 21st century.  Similarly some of the wiring under bridges - which had not been raised - looks to be pretty close to them although nothing unusual to those of use who have looked at much earlier wiring on the WCML and GNML routes - for example the overbridge at the west end of Slough station which was rebuilt including to then current ohle clearances over 40 years back.

 

As far as ground conditions are concerned there's little doubt in my mind that there were either no surveys or very limited surveys and that where someone with past experience suggested any survey holes should be close together this was reportedly ignored according to one former CCE source.  But what is also very clear is that until a retired WR Civil Engineer expert was called in last year the piling people seem to have had no idea about the quantities and frequency of concrete grouting in embankments or indeed the great variation in ground conditions.  Equally it is obvious that there have been design changes 'on the hoof' so to speak as some of the foundations were installed with increasingly widespread use of reinforced concrete cores in a number of the tubular piles, with the original piles still in situ nearby.  What is also noticeable as the scheme progressed has been the appearance of specialist piling contractors (e.g at Twyford and in the vicinity) but even they, from talking to them - on early site visits - were starting with little or no information from NR about the state of various embankments and past slip sites (some of which were quite serious) but equally obviously what has actually been installed has been thought about where normal tube piles would not be adequate. 

 

Another noticeable feature has been the amount of piling work done by road-rail vehicles - seemingly used to the exclusion of a the High Output Train in the Twyford area and Sonning Cutting - and quite likely at a higher cost than originally planned for the piling work.

 

[Hellzapoppin]

Conventional piling, which is augered holes filled with concrete, have a short sleeve fitted which looks like it's a chs pile filled with concrete but that isn't the case. The concrete is poured straight into the hole which allows it to form in and around the ground in the hole. Filling a chs pile wouldn't prove useful and in some ground conditions would allow the pile to sink. I also think the piles you see close by are for the stays at the portals. Hope this helps. LZ

[Peter Kazmierczak]

I'm sure that Hellz.... is correct about some of the piles that are close to each other.

I noticed some between West Drayton and Stockley Bridge that appeared too close together, but now I see that these additional piles are for portal support stays.

[aforsyth]

Continuing on Peter's theme, and as a layman regarding OHLE, what is the standard distance on plainline GWML between the regular portal uprights?

I understand that it will vary for various reasons, but it would be useful to know as a rule of thumb when trying to estimate train speed (discounting use of GPS technology!).

[The Stationmaster]

Continuing on Peter's theme, and as a layman regarding OHLE, what is the standard distance on plainline GWML between the regular portal uprights?

I understand that it will vary for various reasons, but it would be useful to know as a rule of thumb when trying to estimate train speed (discounting use of GPS technology!).

 

I certainly wouldn't use them for estimating speed (mileposts are a lot more accurate - even if some of them are not at correct spacing).   The distance between masts seems to vary considerably in some places but is consistent in others - o doubt for various design reasons and at times due to ground conditions.

 

The picture below shows the large diameter tubes used with the reinforced concrete core piles (in some cases the 'standard' large tube has concrete but that is probably not full pile depth).  The ones shown below have been installed in the vicinity of Twyford where there are some very unstable ground conditions and a past major slip site.  The tubes do not appear to be as long as the reinforcement but it is possible that as has happened elsewhere tubes have been bolted or welded together to extend their length.   All the concrete piles I have seen have tube around them are ground level.  The only (I think) solely concreted bases seem to be some of those in station platforms where a hole has been excavated and then backfilled using concrete - as can just be made out in the second picture below these use a completely different method of arranging the reinforcement more suited - as in this case - to a comparatively shallow hole.  Even the simplest type of stay wire has a tube foundation (using the smallest diameter tube) - an example is shown in the bottom picture below.

 

As far as piles close together are concerned they fall into several categories - some are there for stays/bracing purposes, some are there for additional masts carrying items which are not part of the catenary, some are for signal structures - particularly the lightweight gantry and bracket structures which have no access to the signal heads - and some, as previously mentioned, have never been used for anything and are just sitting there doing nothing.

 

(Click on the pics to enlarge them)

 

Reinforcement 'cage' used inside largest diameter tubes (tubes in the background)

 

 

Reinforcement 'cage' in an excavated foundation on station platform (Twyford)

 

 

Stay wire mounted on small diameter tube (Reading)

 

[jonathan452]

Meanwhile (slightly off topic but related).

 

Barking to Gospel Oak rail upgrade work could go on until end of year - http://www.standard.co.uk/news/transport/barking-to-gospel-oak-rail-upgrade-work-could-go-on-for-another-year-a3533036.html

 

Faults have included incorrect design and late delivery of the huge masts and structures to carry power cables.

There are also fears that NR resources are so spread out on other projects, including Crossrail works on the Great Eastern main line, that delays to the Barking-Gospel Oak project will increase.

 

 

Edited May 8, 2017 by jonathan452

[Hellzapoppin]

Wonder why the conduit alongside the line is in part raised, yet comes to ground level at regular intervals?

Pete, the ATF cable has to be kept at least a metre away from any other cables so in cuttings and on embankments the route is elevated as it's easier to install than conventional concrete troughs. In a flat section where there is more clearance the containment is laid on the ground. This is not always the case as it depends on the local situation but it's a good rule of thumb. The route kicks in around the piles to allow access also worth noting is that you can't put the route at the back as it would be difficult to install any new cable sections.

[Mike Storey]

Meanwhile (slightly off topic but related).

 

Barking to Gospel Oak rail upgrade work could go on until end of year - http://www.standard.co.uk/news/transport/barking-to-gospel-oak-rail-upgrade-work-could-go-on-for-another-year-a3533036.html

 

 

 

Not exactly news (NR announced this at the end of the blockade in February, which TfL shared on their news pages. It was also widely reported in the trade press.) The only thing missing is an agreed plan for the outstanding works, but it had already been announced that additional evening and weekend work would be needed during the rest of 2017. TfL are withholding consent until NR can confirm new delivery dates, of the correctly designed kit, and availability of staff and contractor resources, for the new possessions they wish to have. Given these now fall beyond the normal disruptive possessions applications time limit, this is not unreasonable. Methinks it was a slow news day for the Standard and there is an election coming up!

[The Stationmaster]

Right an update for the area east of Twyford starting with Crossrail territory and working outwards from Ealing Broadway.

 

1. Various electrification associated work, mainly the 25kv additional feeder is still going on but there are possible sundry other jobs taking place as well.  I  noticed the 25kv feeder is also being installed east of Southall.

 

2. Platform extension works visibly in hand at West Ealing and Hayes, nothing much seemingly happening at West Drayton (reference earlier conversation).  There is a large workbase on the Down Side between Iver and Langley which appears to be still very much in use - presumably in connection with the various outstanding work on detail and the 25kv feeder

 

3. A strange bit of signalling has appeared at Maidenhed East with the signal just east of the platform on the Up Main boasting a Position 4 JI - which reads bang road onto the Down Main and to a signal further east on the Down Main which is presumably a fixed red but in rear of that there is a stopping point marker board.  As far as I could estimate from a passing train there is probably enough space for a 3 or 4 car Class16X to reverse so it might be intended for use during stage or commissioning works to allow a service from the west to turnround at Maidenhead on the Mains much as happened at Tilehurst during the Reading works.

 

4. All lines at Maidenhead are wired including the bay, which has an overrun onto the branch as well as leading to the Crossrail stabling sidings, and the reversing siding and stabling sidings.  I don't know about the sidings but the points to/from the reversing siding are very firmly scotched.

 

The ohle, as full catenary, on all 4 running lines finishes just past Maidenhead West and a chain or two short of the 25 mile post.  There is then a gap to a point just west of the M4 overbridge and a chain or so short of  25m60ch where full catenary commences on all four running lines and basically continues to a few hundred yards short of the overbridge east of Ruscombe - probably in the vicinity of 28m70 or thereabouts however catenary continues on the Main Lines to just west of Ruscombe Jcn around about 29m65 but at least one of the intervening sections on the UML is catenary wire only.

 

The 25kv feeder and earth wire are in place most of the distance from Ruscombe to Twyford substation but only the troughing has been laid up the bank to the substation and there is no cable in it.  Most fittings look to be in place on structures from Ruscombe to Twyford overbridge and at 20.40 last night there looked to be quite a lot of activity at the large workbase at Ruscombe.

 

The missing masts at Twyford station are still missing so it looks inevitable that as wiring continues towards Twyford from both the east and the west there will be a gap until the final masts and structures are erected.  Similarly although the test digs were done long ago for the piles for the run-off onto the Henley Branch there has been no piling done so maybe they aren't going to bother (or it has been 'overlooked')

[Northroader]

I noticed in the Uffington area today that besides masts, a lot of the supporting gantries are in place. I've been in the mindset of watching for post placing dot. dot. dot. dot. kind of thing on both sides, but there are places where a gantry supports both sets of wires from a single post on one side of the line, and this repeats for several spaces, so you can get "missing" posts on the other side. Note to self, write 100 times 'I must not jump to conclusions'.

[lmsforever]

I noticed in a photo montage of Trans Pennine electrification showing a new Northern electric passing under standard overhead ie as it is now on the WCML and not the overengineered gate posts on the western,is this a sign of the future?

[The Stationmaster]

I noticed in a photo montage of Trans Pennine electrification showing a new Northern electric passing under standard overhead ie as it is now on the WCML and not the overengineered gate posts on the western,is this a sign of the future?

 

The 'over-engineered posts' come in several different sizes depending on what load they have to carry and the weight and function of the boom or full gantry they are carrying.  The largest ones are used on quadruple track, or longer, spans as they are carrying more weight and presumably strain although they are also used with some designs of boom.  Various of the other masts appear to be exactly the same size in section as those long used on BR 25kv electrification schemes.

 

The view below shows two masts of different size sections quite close together at Tilehurst and it can be seen that the nearer one - carrying a quadruple track gantry which will carry either tensioning gear or will anchor sections of catenary - is larger than the other which is now I think is probably completed with the isolating switch gear for one section of catenary  (work on that only started a few months ago; the year after that catenary was energised, just one of the ongoing jobs of final fitting works and 'bits & pieces that have followed the reported 'completion' date).

 

[Zomboid]

I've whinged about it before, but enough with the 'over engineered'. Unless you're an OLE engineer who has had sight of the specification and the design calculations, you are not qualified to say that. (And nor am I, but I do know a different kind of engineering and I wouldn't be happy with people who don't know what I'm talking about telling me I've done it wrong. I'm sure everyone here has skills that I don't, and I wouldn't go publicly announcing that they'd done something wrong if I didn't know what I was talking about).

 

"Ugly and obtrusive" is fine, as those are judgements which anyone is able to make for themselves.

[ejstubbs]

This may have been posted already, but in case not, it is well worth a read, on current electrification schemes' difficulties. This may help understand the problems also at GOBLIN and EGIP.

 

http://www.railengineer.uk/2017/02/24/egip-electrification-clearance-woes/

 

Just had a read of that this morning.  The article doesn't make the timeline particularly clear, but I did notice this quote from the ORR: “costs of redesigning features and retrospective modifications due to the lack of rigour in the duty-holder’s original design should not be used to inform any cost-benefit analysis”.  That seems a bit rich if the designs had been signed off before the new standard came in to force.  To characterise not designing something to comply with an unratified standard as "lack of rigour" is taking the mick more than somewhat IMHO.  Some of the decisions by the ORR and/or the other regulatory bodies - particularly the failure to allow a derogation for EGIP under the advanced projects criterion - seem to have been perverse, or perhaps more simply made with no understanding of the end-to-end life cycle of infrastructure projects of such a scale.  There's a whole lot that goes on before the first sod is cut.

 

On a completely different note: Mike the Stationmaster's remarks about the planning for the GWML scheme not taking possible (and possibly already known, if the right parties had been consulted) vagaries of geology and ground conditions into account seem to echo one of the key issues that delayed the Edinburgh Trams project, and eventually led to it being curtailed (sound familiar?)  It might be illuminating to get sight of the RAID* registers for both projects.  In the case of the Trams, digging large trenches down 200-plus-year-old streets and being surprised at finding unexpected stuff down there seems a little naive at best, downright incompetent at worst.  A cynic might wonder how much contingency was pared out of the original plan submissions in order to meet a known budget, or to come in with the lowest tender (basically, allowing sales teams to override engineers is always a risk).

 

* RAID = Risks, Assumptions, Issues and Dependencies.  At least if you log each assumption made during the planning and design phases then you should be able to recognise those as potential sources of project risk (ie that the assumption may turn out to be invalid) which ought to have some mitigation built in to the plan - otherwise you end up with an issue, and nobody likes those...

Edited May 11, 2017 by ejstubbs

[The Stationmaster]

Further to previous information about electric services operating to Maidenhead there is a timetable recast and increase in electric worked services commencing Monday 03 July and RealTime Trains for that date shows Maidenhead Carriage Sidings and the Reversing Siding in use with electric trains using platforms 3 (DRL), 4 (URL) and 5 (branch 'bay') from that date.  It is also interesting to note that by then Platform 5 will have been split into 5A and 5B.

 

Presumably commissioning might take place over the immediately preceding weekend as I note stopping services will be using the Main Lines at Maidenhead after 23.45 on the Friday until shortly after 05.00 on the Monday morning.  What is less clear - thus far - is how the Class 387s booked to emerge from the Carriage Sidings after 05.00 on the Monday will get into them  so I suspect there's some STP variations still to appear.

 

A bit of historical information.

 

The Maidenhead station on the present site opened on 1 November 1871 while the original Maidenhead station, east of the River Thames and about a quarter of a mile west of the current Taplow station, had opened on 4 June 1838.  Maidenhead's other station, latterly named Maidenhead (Boyne Hill), was situated on the Wycombe and opened on 1 August 1854 as Maidenhead (Wycombe Branch), it closed on 1 November 1871 when the present station opened.  Quadruple track through the station was opened for traffic on 4 june 1893 thus pre-dating the present station.  Narrow gauge (in the proper, GWR, sense) trains first appeared at Maidenhead in on 14 August 1861 with the first narrow gauge passenger trains passing through from 1 October that year  (i.e before the present station opened) but broad gauge retained a  presence until the final gauge conversion in 1892.

[Karhedron]

Further to previous information about electric services operating to Maidenhead there is a timetable recast and increase in electric worked services commencing Monday 03 July and RealTime Trains for that date shows Maidenhead Carriage Sidings and the Reversing Siding in use with electric trains using platforms 3 (DRL), 4 (URL) and 5 (branch 'bay') from that date.  It is also interesting to note that by then Platform 5 will have been split into 5A and 5B.

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.

[DY444]

IET on 5X27 Wantage Rd to North Pole has lost a pantograph between Didcot and Tilehurst. Damage sustained to overhead line equipment as well.

It appears no matter how robust and over engineered the OHLE equipment is, it can still get damaged.

 

To be fair I don't think this incident was a failure of the infrastructure.  The reports I've seen are that the train went past the present boundary for overhead operation with its pantograph still raised and when it reached an incomplete section of ole the inevitable happened. 

[Edwin_m]

On a completely different note: Mike the Stationmaster's remarks about the planning for the GWML scheme not taking possible (and possibly already known, if the right parties had been consulted) vagaries of geology and ground conditions into account seem to echo one of the key issues that delayed the Edinburgh Trams project, and eventually led to it being curtailed (sound familiar?)  It might be illuminating to get sight of the RAID* registers for both projects.  In the case of the Trams, digging large trenches down 200-plus-year-old streets and being surprised at finding unexpected stuff down there seems a little naive at best, downright incompetent at worst.  A cynic might wonder how much contingency was pared out of the original plan submissions in order to meet a known budget, or to come in with the lowest tender (basically, allowing sales teams to override engineers is always a risk).

 

* RAID = Risks, Assumptions, Issues and Dependencies.  At least if you log each assumption made during the planning and design phases then you should be able to recognise those as potential sources of project risk (ie that the assumption may turn out to be invalid) which ought to have some mitigation built in to the plan - otherwise you end up with an issue, and nobody likes those...

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 think the electrification on Edinburgh tram went reasonably smoothly (relatively at least).  Apart from the signalling cables also being underground I don't see a lot of commonality with the problems on GWML. 

Edited May 12, 2017 by Edwin_m