Great Western Electrification Progress

[themiller]

Wouldn't it be nice if the GW electrification were to be completed to Bristol and Oxford just in time to cascade 800 bi-modes to the MML and be replaced by electric only 801s ordered by the new MML franchisee. I'm sure our DfT have got it covered.

 

[Peter Sarf]

...good thing we've got that rolling programme of electrification to keep these newly-rediscovered skills and processes warmed up, right? Right?

Please please don't remind me .

There might be a need for a gap at the bridge, if the bridge itself was too low to allow OLE between it and the top of the train.

There might be a need to run through with pan down (or have a gap at the bridge or the level crossing) if the gradient of the OLE relative to the track is so steep that the pan would exert unacceptable forces on the wire when being pushed down, or have unacceptable loss of contact when it attempts to follow the wire upwards.

However recent posts suggest neither of these is so, because although the wire is steeper than desirable the consequence is increased wire wear rather than anything more serious.

I would keep the wire there even if relying on the pan to be lowered. That way if the pan is not lowered it is not going to be ripped off by the bridge . The train might be going too fast but at least the damage will be less or less likely.

 

[furnessvale]

Perhaps not with every swing bridge; Trowse Swing Bridge on the GEML for example has continuous electrification. However, this is due to it swinging in a horizontal plane. Most bridges over waterways in the Netherlands, however, have decks that rise upward, splitting in the middle that would be very difficult, if not impossible, to electrify. ProRail (the Dutch rail infrastructure manager) may have taken an executive decision to do this with a number of bridges that could have been electrified, but I'm no expert on the daily operations of the Nederlandse Spoorwegen.

Pedantically, such bridges are bascule bridges not swing bridges, but even so, using conductor bars, rather than wires would make electrifying such a bridge a straightforward proposition.

 

[coppercapped]

You have failed to grasp my argument.
It has nothing to do with HSTs and the number of stops in 60 miles as their operating temperatures are at or near max temperature all day so do not go through repeated heating and rapid cooling cycles many times daily.
Bimode 800s on the Cotswold line are at or near max temperature all the way from Didcot to Worcester/Hereford and return irrespective of stops.
Newbury-Bedwyn is another matter with what, 20 minutes each way and then rapidly cooled again for a couple of hours until next time.
If the B&H was in France or Spain it would have been electrified in the 1960s. If so this argument wouldn't be necessary. French bimodes are for use beyond the wires along branch lines that are mostly single track. The Swiss do not have any bimodes.

The issue with thermal cycling is not the general heating and cooling of the engine as a whole, but the increase in thermal load to the cylinder liners and its seals to the cylinder block, pistons and valves between idling and power being taken for acceleration, the few minutes at full power then idling again as the train makes its next stop.

This was a serious issue with the Paxman Valenta engines used on the HSTs on the GW when this thermal cycle could happen around 6 times per hour for trains on the semi-fast services. From 2005 or thereabouts the Valentas, after 30 years or so in front line services and suffering from cracked crankcases and other ills, were replaced by the 16 cylinder MTU engines. These are two generations later in design, materials and construction and, although operating the same services as the Valentas show no sign whatsoever of suffering from the same problems.

I wrote in an earlier post that your worries are misplaced.

In any event, the DfT's contract with Agility Trains for the Train Service Provision included the use of the IEP procured trains on the Bedwyn service. If Agility were concerned that the trains' reliability or time between overhauls would be affected by such operation then it would have ordered enough train sets from Hitachi to meet the timetabled requirements. Don't forget that the DfT did not order a given number of trains - its contract with Agility Trains calls for the supply of a given number of diagrams. How Agility fulfils that requirement is up to it.

 

[59CosG95]

Pedantically, such bridges are bascule bridges not swing bridges, but even so, using conductor bars, rather than wires would make electrifying such a bridge a straightforward proposition.

Indeed, most swing bridges and bascule bridges use conductor bars anyway - I'm embarrassed that I didn't know the correct name, given that I study Civil Engineering!
At the risk of digressing, I do however maintain my point that having a discontinuous section of wiring to appease a minute percentage of NIMBYs would add a farcical amount to the cost of what is already an overly expensive project; the sooner both parties reach a decision to electrify conventionally, the better.

 

[JN114]

At the risk of digressing, I do however maintain my point that having a discontinuous section of wiring to appease a minute percentage of NIMBYs would add a farcical amount to the cost of what is already an overly expensive project; the sooner both parties reach a decision to electrify conventionally, the better.

Point of order - any gap at Steventon would be due to engineering difficulties - not NIMBYs. Local residents have no issue with Electrification (unlike the Goring gap brigade); bridge is listed so can’t be rebuilt in the same way as others.

 

[SamYeager]

I'll just repeat this from upthread before the disccussion on gaps at Steventon goes any further.

There will be no gap at Steventon - this seems to be an urban myth that won't die. One of the Network Rail electrification engineers stated at an IMechE meeting about a year ago that Network Rail accepts that (contact) wire wear will be higher than desirable at this point until such time as the bridge clearances are improved or the level crossing replaced. Or both. He showed a set of plots showing how different vertical profiles of the contact wire had been simulated in order to obtain the best possible contact wire/pantograph interaction as possible - one of these will be installed.

 

[jimm]

Point of order - any gap at Steventon would be due to engineering difficulties - not NIMBYs. Local residents have no issue with Electrification (unlike the Goring gap brigade); bridge is listed so can’t be rebuilt in the same way as others.

Until now, Network Rail has been playing nice with the villagers and Vale of White Horse Council. It still wants to demolish the bridge and build a replacement in the same spot, preferably next year, as their most recent statement from last September states.

http://www.steventon.info/pdf conve...dge temporary solution statement 11-09-17.pdf

If there is much more delay in the Vale council making a decision on listed building consent for demolition and approving a replacement, we could be heading for an appeal direct to the Planning Inspectorate.

It is regrettable that the whole thing has got wrapped up in the wider issues of access across the railway in the village. level crossings included, at what is a very peculiar and probably unique location - along with the lengthy alternative road routes while there is no bridge.

Had the bridge been a bog-standard bit of steel plate and girders, things would never have got this far. And if it had stood in the way of an IK Brunel project, down it would have come straight away.

 

[Mag_seven]

Mentor’s test runs turned up nothing on mains and reliefs, however a block to electric traction has been imposed this afternoon in Hayes Bay, with strong evidence that an OHLE defect at the London end of the Bay platform has been causing Pan damage. Padd - Hayes shuttles were initially cancelled; now being operated with a 2 car turbo on each circuit. NR looking to carry out rectification work overnight.

More OLE issues with Hayes Bay this morning - from GWR Journey Check:

"Alterations to services between Hayes & Harlington and London Paddington

Due to damage to the overhead electric wires at Hayes & Harlington some lines are blocked. Disruption is expected until 14:00 23/01.
Train services between Hayes & Harlington and London Paddington have been revised.
Customer Advice
Due to overhead line damage at Hayes & Harlington, Platform 5 is closed to electric trains. This means the Hayes Shuttle electric services are running with diesel trains today, formed of 3 coaches.
Last Updated:22/01/2018 20:42"

 

[JN114]

More OLE issues with Hayes Bay this morning - from GWR Journey Check:

"Alterations to services between Hayes & Harlington and London Paddington

Due to damage to the overhead electric wires at Hayes & Harlington some lines are blocked. Disruption is expected until 14:00 23/01.
Train services between Hayes & Harlington and London Paddington have been revised.
Customer Advice
Due to overhead line damage at Hayes & Harlington, Platform 5 is closed to electric trains. This means the Hayes Shuttle electric services are running with diesel trains today, formed of 3 coaches.
Last Updated:22/01/2018 20:42"

It’s the same issue, NR were not successful in repairing it previously.

 

[Class 170101]

Why would you want to have a gap?

The Dutch over have those gaps over the river bridges because they're necessary, given that the bridges in question are swing bridges. We have absolutely no requirement to have a gap at Steventon to soothe our injured NIMBY egos.

Nothing to do with NIMBYs. I was thinking the overall wire height could be lower over the section to fit under the bridge save for the level crossing where there would be a gap to get round the problem of wire height.

The NR engineers may well see the contact issue as a problem with extra wear and tear but this has to be rectified with replacement contact wire which require possessions - not exactly easy to get the right length possession to replace the degraded contcat wire every time whilst yet keeping passengers off replacement buses.

 

[coppercapped]

Nothing to do with NIMBYs. I was thinking the overall wire height could be lower over the section to fit under the bridge save for the level crossing where there would be a gap to get round the problem of wire height.

The NR engineers may well see the contact issue as a problem with extra wear and tear but this has to be rectified with replacement contact wire which require possessions - not exactly easy to get the right length possession to replace the degraded contcat wire every time whilst yet keeping passengers off replacement buses.

And how often do you think the contact wire will need to be replaced? Weekly? Monthly? Annually?
How often does normal contact wire need to be replaced? At the most a tension length would need to be replaced - about 1,000 metres. It can be done overnight.

 

[Class 170101]

And how often do you think the contact wire will need to be replaced? Weekly? Monthly? Annually?
How often does normal contact wire need to be replaced? At the most a tension length would need to be replaced - about 1,000 metres. It can be done overnight.

I have no idea how often the contact wire is replaced perhaps you would enlighten me but I am sure the NR engineer would like to replace it on the fewest the number of occasions they have to.

 

[coppercapped]

I have no idea how often the contact wire is replaced perhaps you would enlighten me but I am sure the NR engineer would like to replace it on the fewest the number of occasions they have to.

Your last remark is certainly true! As far as the life of the contact wire goes, it obviously depends on a number of factors such as: the cross-section, the number of pantograph passes, any atmospheric corrosion or local damage and the tension. There are certainly other variables. There were reports in the press on the occasion of the replacement of the GE's original fixed length wiring between Liverpool Street and Shenfield some five or six years ago that the contact wire was original. That means it lasted some 60 years. On the other hand the SNCF replaced much of the contact wire on the original Paris-Lyon LGV after 'only' 29 years because of fatigue cracking.

So I think one can assume that contact wire normally lasts for anything between 30 and 60 years. In any event one hopes that the issue of the close proximity of the road bridge and the level crossing at Steventon can be solved before the wire needs replacing...

 

[Andyjs247]

Could the maximum height of road vehicles using the crossing be restricted somehow - using the type of barrier often seen at car parks? Then it might be possible to keep the contact wire at a lower safe height.

 

[TwistedMentat]

That would probably involve a new set of council applications to get the maximum height changed and then all the problems as drivers with tall loads running into any bars that have been installed since they last drove along. Not to mention drivers following their satnavs and ignoring road signs.

I would expect NetworkRail to have explored that option but probably found it wasn't worth the hassle. Especially if they've already got some long term permanent fixes in the pipeline.

 

[jimm]

At least one of the two level crossings will have to allow for tall vehicles to get across in the long term - the crossings are the only road access to the part of Steventon south of the railway.

What Google Maps shows that looks like a road running south of the railway and joining the B4017 near the bridge is a private track, not a road, as can be seen by zooming on on the satellite image.

The long-term permanent fix is the one that Network Rail has been proposing from day one - demolish and replace the existing road bridge - though they have now said they will not be shutting the Stocks Lane crossing once a new road bridge is in place, which was part of the the initial plan.

 

[Stewart2887]

The steelwork either side of Steventon bridge has gone in in the last week or so. Just a couple of big bits and some small steelwork to go, then the wires

 

[Class 170101]

Grayling dropped a hint here that the Valleys may well not be wired now

http://www.parliamentlive.tv/Event/Index/520222f2-1679-4da9-9ab6-65f9bf5f195f
See around 17:27 to 17:29

However I have to say I think he has forced the Welsh minister to make that decision should it come forth by witholding funding for schemes he doesn't support.

 

[Class465fan]

What's his excuse for this one now?

 

[GRALISTAIR]

Grayling dropped a hint here that the Valleys may well not be wired now.

No question about it - certainly not fully wired

 

[CdBrux]

What's his excuse for this one now?

If you take a look at the South Wales Metro thread then it's complicated but seems to boil down to the fact the Welsh Government are wanting to do something else with the lines

 

[59CosG95]

All portals are now up through Swindon, and SPS can be seen in the distance, according to this tweet (which I believe is from our own @GazK) https://twitter.com/25kV/status/956452015974027265.

 

[jyte]

Any reason why they're using a Twin Track Cantilever over platform 1 rather than a single track one?

 

[59CosG95]

Any reason why they're using a Twin Track Cantilever over platform 1 rather than a single track one?

Possibly clearances with the existing buildings on P2/3, along with the provision for electrifying the line that passes to the north of P1, should it be required.

 

[GazK]

Any reason why they're using a Twin Track Cantilever over platform 1 rather than a single track one?

Because the structures have to reach over the goods loop to get to P1 road.

 

[jyte]

Because the structures have to reach over the goods loop to get to P1 road.

Whoops I forgot about that haha.

Nice to see work at Swindon regardless.

 

[3973EXL]

B&H work this week.

Two more wire runs gone up. Now fully wired west of Thatcham LC and east of Racecourse station are two sections on the up (gap between them) and the existing section on the down.

East of Theale around the M4 bridge missing masts are going up.



From Southcote Junction there a few masts missing on the down side with work on the missing masts from Calcot Mill FP crossing to Theale east.

No work at any station, expect it will be done during the closures.

All masts appear to be up from Theale West to halfway along Ufton Loop. Still some masts missing from there to Aldermaston, but SPS going up where possible.

From Aldermaston to Thatcham, except for at least one mast and three cantilevers, steel work looks complete. Most SPS also up.

 

[76020]

I did a return trip from London Paddington to Swindon today so here is an update:-
As reported elsewhere about a month ago I would like to confirm that the last unwired platform at Paddington, which is platform 2, is now wired, at last!
It was pitch black when I returned so I could only see the up side on my outward journey, so onto to Didcot, there about four masts with booms and I think they was wired as well from the beginning from the advoiding line to Oxford, but I could see nothing after that, they may well be piles further on but you cannot see this from the main line.
The Steventon gap has now all it's masts installed but nothing much else, no cross-arms for about a half a mile either side of the infamous bridge and second level crossing, the situation about the bridge is unchanged according to the Steventon Village Website and it is still with the Vale of White Horse Planning Department with a resolution due Jan or Feb 2018.
Wiring starts again just after MP57 and goes all the way through to about MP73 with two gaps, one for about two miles at about MP67 and another for about one mile at about MP71, the return wire goes onto for a mile or two past MP73, the A/T is largely complete from MP57 to MP73 but there are gaps and it is installed on temporary fittings at some other locations.
Masts are all the way to Swindon station now and apart the final approach to Swindon they all have they cross-arms fitted as well, Swindon is about MP77/78
On the way back I got on a Class 800 for the first time and I was impressed, even though the seats were hard, the train changed over to electric traction, I am sure at Didcot and not Reading, I was sitting right below the pantograph and I did not hear any noise during the change over, not like the Class 313's at Drayton Park when you think the roof is going cave in!
If it was not for those very nice people at Steventon I am sure Network Rail could have got their beautifully bridge fully rebuilt by now and the juice switch onto Swindon by this summer, let's see what happens if anything.

 

[FGW_DID]

I did a return trip from London Paddington to Swindon today so here is an update:-
As reported elsewhere about a month ago I would like to confirm that the last unwired platform at Paddington, which is platform 2, is now wired, at last!
It was pitch black when I returned so I could only see the up side on my outward journey, so onto to Didcot, there about four masts with booms and I think they was wired as well from the beginning from the advoiding line to Oxford, but I could see nothing after that, they may well be piles further on but you cannot see this from the main line.
The Steventon gap has now all it's masts installed but nothing much else, no cross-arms for about a half a mile either side of the infamous bridge and second level crossing, the situation about the bridge is unchanged according to the Steventon Village Website and it is still with the Vale of White Horse Planning Department with a resolution due Jan or Feb 2018.
Wiring starts again just after MP57 and goes all the way through to about MP73 with two gaps, one for about two miles at about MP67 and another for about one mile at about MP71, the return wire goes onto for a mile or two past MP73, the A/T is largely complete from MP57 to MP73 but there are gaps and it is installed on temporary fittings at some other locations.
Masts are all the way to Swindon station now and apart the final approach to Swindon they all have they cross-arms fitted as well.
On the way back I got on a Class 800 for the first time and I was impressed, even though the seats were hard, the train changed over to electric traction, I am sure at Didcot and not Reading, I was sitting right below the pantograph and I did not hear any noise during the change over, not like the Class 313's at Drayton Park when you think the roof is going cave in!
If it was not for those very nice people at Steventon I am sure Network Rail could have got their beautifully bridge fully rebuilt by now and the juice switch onto Swindon by this summer, let's see what happens if anything.

The ‘leccy’ / diesel change over point is at Moreton Cutting for all Down trains and non-stop Up trains. If an Up train is stopping at Didcot, they are authorised to raise the pan whilst stationary during the Station stop.