GWML Electification

[RJS1977]

I didn'tthink there had been any railway undertakers since the Brookwood Necropolis Railway closed...

[Mike Storey]

There must be a balance with form over function.

 

The problems with the (under-engineered) ECML OHLE have been well-documented, but have things swung too much the other way? 

 

I am not sure if it was on this thread or another one, but essentially, according to engineering peeps, no. The problem is the resilience necessary to deal with the wave form created by the upward and rolling pressure of the first panto when the second panto hits it. Whether a more aesthetically pleasing version, with the same performance characteristics, can be achieved at reasonable price, needs someone else to comment. They would appear to be working on something better looking for the Bath area, but at what cost?

[Edwin_m]

Some variable message gantries that recently went in on the M1 (on the section visible from Hardwick Hall - where incidentally HS2 is likely to be adjacent) appear to be the same structures as elsewhere but painted brown.  This does seem to make them slightly less conspicuous against a background of winter trees, and in summer it probably doesn't matter as the foliage would block most of the critical view of the motorway. 

 

In my view that's the most likely answer to this - presumably if they can't be painted on site then they can be unbolted piece by piece and replaced by painted ones, with some sort of temporary structure holding the wires in place meantime. 

Edited January 16, 2016 by Edwin_m

[uax6]

I always thought that the lattice gantries used on the WCML and the GE main line to Cambridge were very eligant structures, no heavy stellwork, just nice lightwieght things. Are these type of structure not suitable for multiple pans then, as they seem to work ok with 12 cars units down here?

 

Andy G

[surfsup]

There are two rather interesting and revealing threads running over on Rail UK forums about this subject, with some comment from a Local and a few in NR & The industry working on the project.

 

Goring Gap thread. Of note are the posts by Philip Phlopp.

 

http://www.railforums.co.uk/showthread.php?t=123126

 

GWML Project

 

http://www.railforums.co.uk/showthread.php?t=83452

 

Of course, one of the Idyllic comprimises that the residents want are that of the same OHLE system as the ECML - Overhead headspans. Unfortunately, there's a reason why even as part of the GWML Electrification project the headspans between Paddington and Airport Junction are being removed - that very same reason why NR isn't keen on it staying on the ECML either. As seen in the past, if a pantograph or foreign object becomes entrapped within the headspan system, it has a tendancy to bring the whole lot down. That's why reliability and robustness was built into the F&F design.

[RJS1977]

I am not sure if it was on this thread or another one, but essentially, according to engineering peeps, no. The problem is the resilience necessary to deal with the wave form created by the upward and rolling pressure of the first panto when the second panto hits it. Whether a more aesthetically pleasing version, with the same performance characteristics, can be achieved at reasonable price, needs someone else to comment. They would appear to be working on something better looking for the Bath area, but at what cost?

 

The Bath area gantries/masts will only have to support wires over two tracks, not four as at Goring. Less weight to support, less distance to bridge and lower potential upward forces as on a 4-track line there is the possibility (albeit remote) of four pantographs all passing under the same gantry simultaneously!

[Ron Ron Ron]

There must be a balance between form and function.....

 

Yep! Equilibrium, as in Ying and Yang.

 

Like replacing the Ying Ying of Class 66's with the Ying and Yang of Bi-modes.  

 

Mmmm..... I'm not sure what will happen when everything ends up all-electric?

Yang Yang will be all out of balance again.

OK Scrap that theory......

 

 

 

.

[locoholic]

Of course, one of the Idyllic comprimises that the residents want are that of the same OHLE system as the ECML - Overhead headspans. Unfortunately, there's a reason why even as part of the GWML Electrification project the headspans between Paddington and Airport Junction are being removed - that very same reason why NR isn't keen on it staying on the ECML either. As seen in the past, if a pantograph or foreign object becomes entrapped within the headspan system, it has a tendancy to bring the whole lot down. That's why reliability and robustness was built into the F&F design.

 

I suppose we should be grateful that some form of overhead conductor rail isn't being constructed, rather than those flimsy wires!

[Vanders]

You're quoting almost verbatim from The Hitch-Hiker's Guide to the Galaxy! I had never thought of Network Rail as a kind of Vogon Constructor Fleet, but now you've mentioned it...

 

 

The High Output Plant system hung in the air in much the same way that bricks don't.

[Mike Storey]

There are two rather interesting and revealing threads running over on Rail UK forums about this subject, with some comment from a Local and a few in NR & The industry working on the project.

 

Goring Gap thread. Of note are the posts by Philip Phlopp.

 

http://www.railforums.co.uk/showthread.php?t=123126

 

GWML Project

 

http://www.railforums.co.uk/showthread.php?t=83452

 

Of course, one of the Idyllic comprimises that the residents want are that of the same OHLE system as the ECML - Overhead headspans. Unfortunately, there's a reason why even as part of the GWML Electrification project the headspans between Paddington and Airport Junction are being removed - that very same reason why NR isn't keen on it staying on the ECML either. As seen in the past, if a pantograph or foreign object becomes entrapped within the headspan system, it has a tendancy to bring the whole lot down. That's why reliability and robustness was built into the F&F design.

 

Many thanks for these links. I have dipped into RailForum occasionally before, but never seen that thread. It is superb, with the likes of Philip Plopp and others, who really know their stuff technically and clearly know what is really going on. It is clear that there are, in the vast majority of situations, perfectly logical reasons for things being done in the way they are, given the hospital pass they were first delivered.

 

Having read about 40 of the c.130 pages and counting, I feel much better informed and more optimistic.

[Jonboy]

Do you think that if I start a community protest about the same spans towering above the town of Didcot across the embankment and demanding changes to all the masts, per the precedent being set in Goring, that NR would see some kind of sense against wasting public funds to this extent?

 

Could then go onto protest the ruining of the view from the Ridgeway, The Clumps, Great Western Park, White Horse Hill etc...

 

Or do they intend to stall the Goring residents for a while, and then claim the failure to act as promised is all the fault of the next CEO or significant figurehead to fall on their sword over the project, and that its now too late to act without significant disruption/cost? 

[The Stationmaster]

I find some of the residents' action a bit incomprehensible,  Various of these structure were in place before they started their action group back last year including information about the design of structures on various websites plus film of trial installations and, for those who cared to look, examples of it in place on the GE mainline (for renewals) back in 2014.  One thing to shout, quite another to do it at the right time.

 

Equally it has long been made clear in the public arena, including directly by NR, that the design is intended to avoid the problems encountered elsewhere with headspan construction both in terms of reliability and (although the precise words have not been used) in terms of resilience to cater with increased pantograph uplift forces especially at higher speeds.  And it should be equally obvious to anyone who cares to, or is able, to look that the foundation piles are being sunk in the most logical places clear of drains and clear of the swept envelope and the sighting of signals and that in places this will inevitably result in girderwork or the  (very neat as it happens) monogirders for catenary tensioning spanning all 4 running lines.

 

Interestingly the siting of signals, quite a number of which are on retained 1960s straight posts, suggests that the catenary and structure placing is unlikely to interfere with signal sighting to the extent seen on the WCML and the availability of LED signal heads has permitted some very minimalist signal structures, without staff access, to be installed un place of large 4 track gantry structures.  Placing masts in the 10 foot - which is being done in one or two places where the situation clearly permits - would inevitably result in some massive signal structures which judging by examples elsewhere would make the ohle structures look positively tiny.

 

The structures are clearly in some respects more 'brutal' than those used on the WCML but I suspect that one reason for that is comparative cost plus of course the mechanical spec would appear to in fact be more equivalent to the early BR 25kv installation on the Styal Loop (which could withstand high uplift forces at speeds far in excess of linespeed) rather than equivalent to the later and cheaper catenary used elsewhere on the WCML.

 

The points made by Mike about changes in legislation etc (which seem somewhat at odds with public utterances by Govt  ) are not only informative but show how tardiness in construction has been overtaken by changes in legislation - NR has perhaps made a rod for its own back?  However NR have stated in writing to the action group that the final design for construction was approved in December 2014 (er, after work had started) but of course what exactly was meant by 'final design' could be open to interpretation as the structure design obviously predates scheme detail design and, as I said, work was already underway by then.  But having said that it is interesting also to note that the action group is basing its main plank of opposition on the Countryside Rights and Way Act, 2000, Section 85 and not on more recent legislation.

 

That apart it appears that if NR has failed anywhere it is in failing to carry out its promised consultation with consultation with the AONB Conservation Boards however that 'promise' was actually made by Atkins in the environmental study rather than by NR itself.  So there does appear, on the face of information published by the action group, to have been some managerial sloppiness on the part of NR or its consultants - perhaps within the management of the project (but that is conjecture on my part).

 

Rather amusingly the action group seems to have tumbled to the fact that following electrification not all trains will be electrically powered.  Quite why they should 'chalk that up' seems to me rather odd as I don't think that anyone has ever stated that anything otherwise would be the case, and to even expect it would seem to me to be shooting for the moon.  Apparently the action group want a count of which trains will still be diesel hauled which, rather perversely, makes me wonder if they really are looking at the railway at all as all they have to do is go out and count them or even maybe - as some are claiming their view will suffer - sit at home and count them.

[The Stationmaster]

My comment was meant as a joke.

Ah, you clearly don't know the area then  (however some of the clouds have gone since the closure of Didcot A power station - and the construction of that created even more fuss and shouting than this one).  As for the residents of Goring they seem to have been successful in preventing a closed pub being converted into a Tesco Local (and it isn't even in the village but is by the railway station) and I do wish they wouldn't park their cars on the main (only) through road although it is worse on the other side of the river in Streatley.

[Mike Storey]

I find some of the residents' action a bit incomprehensible,  Various of these structure were in place before they started their action group back last year including information about the design of structures on various websites plus film of trial installations and, for those who cared to look, examples of it in place on the GE mainline (for renewals) back in 2014.  One thing to shout, quite another to do it at the right time.

 

Equally it has long been made clear in the public arena, including directly by NR, that the design is intended to avoid the problems encountered elsewhere with headspan construction both in terms of reliability and (although the precise words have not been used) in terms of resilience to cater with increased pantograph uplift forces especially at higher speeds.  And it should be equally obvious to anyone who cares to, or is able, to look that the foundation piles are being sunk in the most logical places clear of drains and clear of the swept envelope and the sighting of signals and that in places this will inevitably result in girderwork or the  (very neat as it happens) monogirders for catenary tensioning spanning all 4 running lines.

 

Interestingly the siting of signals, quite a number of which are on retained 1960s straight posts, suggests that the catenary and structure placing is unlikely to interfere with signal sighting to the extent seen on the WCML and the availability of LED signal heads has permitted some very minimalist signal structures, without staff access, to be installed un place of large 4 track gantry structures.  Placing masts in the 10 foot - which is being done in one or two places where the situation clearly permits - would inevitably result in some massive signal structures which judging by examples elsewhere would make the ohle structures look positively tiny.

 

The structures are clearly in some respects more 'brutal' than those used on the WCML but I suspect that one reason for that is comparative cost plus of course the mechanical spec would appear to in fact be more equivalent to the early BR 25kv installation on the Styal Loop (which could withstand high uplift forces at speeds far in excess of linespeed) rather than equivalent to the later and cheaper catenary used elsewhere on the WCML.

 

The points made by Mike about changes in legislation etc (which seem somewhat at odds with public utterances by Govt  ) are not only informative but show how tardiness in construction has been overtaken by changes in legislation - NR has perhaps made a rod for its own back?  However NR have stated in writing to the action group that the final design for construction was approved in December 2014 (er, after work had started) but of course what exactly was meant by 'final design' could be open to interpretation as the structure design obviously predates scheme detail design and, as I said, work was already underway by then.  But having said that it is interesting also to note that the action group is basing its main plank of opposition on the Countryside Rights and Way Act, 2000, Section 85 and not on more recent legislation.

 

That apart it appears that if NR has failed anywhere it is in failing to carry out its promised consultation with consultation with the AONB Conservation Boards however that 'promise' was actually made by Atkins in the environmental study rather than by NR itself.  So there does appear, on the face of information published by the action group, to have been some managerial sloppiness on the part of NR or its consultants - perhaps within the management of the project (but that is conjecture on my part).

 

Rather amusingly the action group seems to have tumbled to the fact that following electrification not all trains will be electrically powered.  Quite why they should 'chalk that up' seems to me rather odd as I don't think that anyone has ever stated that anything otherwise would be the case, and to even expect it would seem to me to be shooting for the moon.  Apparently the action group want a count of which trains will still be diesel hauled which, rather perversely, makes me wonder if they really are looking at the railway at all as all they have to do is go out and count them or even maybe - as some are claiming their view will suffer - sit at home and count them.

 

All true, however, the Countryside etc Act of 2000 only requires a statutory undertaking to take account of an AONB in its design, subject to etc etc. Thus, I doubt the action group will get very far on that one, especially as it can be readily proven that the portal system is necessary for >125mph plus multiple panto running.

[jonny777]

Ah, you clearly don't know the area then  (however some of the clouds have gone since the closure of Didcot A power station - and the construction of that created even more fuss and shouting than this one).  As for the residents of Goring they seem to have been successful in preventing a closed pub being converted into a Tesco Local (and it isn't even in the village but is by the railway station) and I do wish they wouldn't park their cars on the main (only) through road although it is worse on the other side of the river in Streatley.

 

No, I don't know the area, and given the attitude of some of the residents - I don't wish to know the area either. [1]

 

That Railforum thread is an eye-opener for me; showing the complete knowledge of the technical and legal aspects on the NR side, against the not-too-veiled legal threats, bluff and bluster from the 'green ink' residents side.

 

(O/T  [1] We have had a similar exercise here, with the route of the high voltage power cables from the projected Hinkley Point C power station. Heaven only knows how much public money has been spent on consultations, alternative options, glossy brochures to every household, local questionnaires and the like. No wonder very little ever gets done.)

[D1059]

I've just seen that BBC South Today article on the TV

 

The action groups arrogance is staggering - apparently THEY are permitting NR to proceed with the electrification as long as they come back and replace the gantries later on

[phil-b259]

The ECML OHLE looks very attractive by comparison.

It is also VERY flimsy - there is a very good reason why no other Europien railway organisation uses headspan type OHLE supports on high speed lines and a cursory glance at infrastructure faults on the ECML will show the proportion of OHLE faults is far higher than the WCML which uses portal structures.

 

Put simply head spans are only good for slow speed lines - if you actually want a electrified railway capable of supporting high speeds then you need portal style structures. Anything else is simply delusional and people believing it need to wake up to the realities of physics rather than wanting the impossible.

Edited January 17, 2016 by phil-b259

[Peter Kazmierczak]

If the all singing and dancing Hitachi thingy is to be used eventually on the ECML too, will the OHLE have to be considerably modified for the "two-pan" effect?

[brian daniels]

In Hungary they paint the masts green.

[Mike Storey]

If the all singing and dancing Hitachi thingy is to be used eventually on the ECML too, will the OHLE have to be considerably modified for the "two-pan" effect?

 

Yes. A portal structure has been on trial near Potters Bar for some time. OLE had already been modified/strengthened to some extent for the NoL Eurostars which GNER used for a while, between KX and Leeds, but still with headspans, as existing max speeds still applied. I understand it will be possible to replace headspans with portals using the existing masts in almost all locations, so not the same extent of work needed as for GWML (or indeed MML north of Bedford). That will mean the piling problems, cable location, bridge and tunnel heights are not a major factor. Major re-signalling, signalling immunisation and revised, enhanced layouts are nowhere near the scale of GWML either, only where platform extensions or additions (as at KX) and new depot links etc will be necessary.Following the NoL Eurostar works, I would imagine gauge clearance is not a problem south of Leeds and York, and possibly not at all given the work that was done when it was thought the Mark IV's were going to tilt (although that work was never completed when tilt was cancelled, although still needed for overhang).

Edited January 17, 2016 by Mike Storey

[jamie92208]

Funny how things have to be re learned.   The Midland used almost all portal structures on the Lancaster Morecambe Heysham Electrification in 1907 apart from a couple of Twin track cantilevers where the LNWR wouldn't let them plant a mast near their running line.   The system was running at over 95% reliability within 6 months of opening and that included the power station and the trains.   Portals were again used on the Woodhead line though for much heavier catenary and of course on the WCML.  

 

I am just sorry that all this has had to happen and feel for the poor guys who are trying to make it happen as it must be very frustrating for them.  

 

As to other designs of OHLE there was some sort of contest a couple of year ago sponsored by one of the magazines and at least 4 designs from design schools did appear but they all looked very expensive to produce.  I can't remember if it was Rail or Modern Railways.

 

Jamie

[billbedford]

Maybe, in the interest in pushing things to the limits of the absurd, someone should suggest that they get these people to design the new OHLE :-)

[Peter Kazmierczak]

Having watched BBC South Today too, obviously the telephoto views of the structures don't do them any favours.

 

However, what I think would be a real visual improvement is if the top of the supports didn't extend beyond the gantry itself. It just makes the whole thing look so untidy and haphazard.

 

Do the supports extend beyond the top of the gantries for a particular reason?

[lmsforever]

Its not that a wonderful place and the nimbys do seem to be arrogant but many people are nowadays due to the media playing up to them.

[RJS1977]

In Hungary they paint the masts green.

 

Tri-ang did that too!