GWML Electification

[lmsforever]

Thats a welcome sight at least work is progressing hope that the wires follow quickly ,but the masts still look over engineered  suppose that its the way of the world now H &S is first and foremost along with inbuilt redundact. 

[rodent279]

Thats a welcome sight at least work is progressing hope that the wires follow quickly ,but the masts still look over engineered  suppose that its the way of the world now H &S is first and foremost along with inbuilt redundact. 

They might look over engineered, but I'd like to see how they compare weight-wise with the gantries used on the WCML. Also, they might be easier to manufacture, they look like they are one piece extrusions.

[96701]

Thats a welcome sight at least work is progressing hope that the wires follow quickly ,but the masts still look over engineered  suppose that its the way of the world now H &S is first and foremost along with inbuilt redundact. 

140 mph running with 2 pantographs is different to Euston to Manchester & Liverpool, Weaver Jct to Glasgow, ECML, MML, LT&S, Norwich et al.. Nothing to do with H & S, all to do with physics

[jim.snowdon]

140 mph running with 2 pantographs is different to Euston to Manchester & Liverpool, Weaver Jct to Glasgow, ECML, MML, LT&S, Norwich et al.. Nothing to do with H & S, all to do with physics

As is >140mph running in Europe with two pantographs, yet none of the European structures on their high speed lines appear to be so over-engineered as those on the GWML.

 

Jim

[lmsforever]

When will 140mph running happen the way DAFT are going I think 125mph will be a problem ?

[kevpeo]

In Europe the pans are generally 8-16 coaches apart. We are going to do it on two 5-cars!

[phil-b259]

When will 140mph running happen the way DAFT are going I think 125mph will be a problem ?

 

Any speed over 125mph will require 'in cab' signalling as the ORR / RSSB do not consider it safe to / practical to use lineside signals to give the driver instructions over 125mph - particularly as said signals also have to deal with slow moving freights, etc.

 

This is entirely separate to the electrification woes - although the chosen top speed has had an impact on the actual design specification of the OHLE

 

With the 800s being designed to have a top speed of 140mph under OHLE and the OHLE also rated for that speed, all that is needed is a suitable in cab signalling system to be 'overlaid' onto the GWML signalling. How long it takes for that to happen though is the question.....

[Titan]

In Europe the pans are generally 8-16 coaches apart. We are going to do it on two 5-cars!

 

However the units will use the pans on the outer cars only, giving a minimum spacing of approx 9 cars - due to the pans being on the inner ends of the outer cars.

[rodent279]

As is >140mph running in Europe with two pantographs, yet none of the European structures on their high speed lines appear to be so over-engineered as those on the GWML.

 

Jim

Is there any running at over 200km/h in Eurpoe that is NOT on specially built high speed lines? Genuine question-I don't know.

[Zomboid]

I heard somewhere that if they have to run a pair of 800s with one of the inner pans raised for any reason, they'll be limited to less than 125.

No idea if it's true or not, or whether it's applicable to the GWML or ECML.

[jamie92208]

Is there any running at over 200km/h in Eurpoe that is NOT on specially built high speed lines? Genuine question-I don't know.

 

As far as I know there has been some limited 200 kph running on classic lines in France but apart from that I'm not aware of any. IIRC it was in the Loire valley on a stretch that was bypassed by the first section of the TGV Atlantique.  I think that the 200 kph running was dropped soon after the TGV line opened.

 

Jamie

Edited August 24, 2017 by jamie92208

[HillsideDepot]

Just to add to my previous post from Callow Hill, I came across these photos on Network Rail Western's Twitter feed of the work in progress there.

I believe the TV cameraman is from BBC Points West (is our local news programme still called that?) as there was a short piece on the BBC Wiltshire webpage.

 

Meanwhile Down at Hullavington work is less well advanced

[Fat Controller]

As far as I know there has been some limited 200 kph running on classic lines in France but apart from that I'm not aware of any. IIRC it was in the Loire valley on a stretch that was bypassed by the first section of the TGV Atlantique.  I think that the 200 kph running was dropped soon after the TGV line opened.

 

Jamie

The line from Paris via Tours to Bordeaux was upgraded to 200kph from sometime in the 1970s, I believe. The northern part was superceded by LGV-Atlantique in 1990, but the bit from Tours to Bordeaux still carried 200 kph trains until the new line towards Bordeaux was opened a few months ago. The conditions for 200 kph running were supression of all level crossings, and fencing of the line to stop intrusion by large game (and associated hunters). The line was still electrified at 1500V dc; motive power were the CC6500 class, those locos dedicated to the 200 kph workings carried a special livery (known as La Capitole, after the flagship working), and were fitted with a system for signal repitition in the cab. When the LGV Atlantique opened, the principal workings beyound Tours went over to TGV working, but the line remained a mixed-traffic railway.

Subsequently, 200 kph working has been introduced on two other rotes, I believe; between Strasbourg and Mulhouse in the Rhine Valley, and on the line from Paris to Clermont Ferrand. Both lines are 25kV ac, and trains are hauled by BB26000 Sybics.

[The Stationmaster]

...and here they are (or at least the ones slightly further up the hill towards Callow Hill).

 

2017 08 23 (1)b.jpg

 

2017 08 23 (6)b.jpg

 

2017 08 23 (12)b.jpg

 

2017 08 23 (17)b.jpg

 

2017 08 23 (18)b.jpg

 

2017 08 23 (21)b.jpg

 

2017 08 23 (24)b.jpg

 

I'm not an expert, but these don't look too far off from being wired. There are 4 plain masts in a row alongside the Up side a little way from the road bridge, and not really photographable as there is a works compound opposite them, but visible in the last photo above the horizontal part of the railings to the access point,which I assume need something fitting to them, but other than that they look ready. 

 

There is a series of major week long possessions coming up shortly on the Badminton route to install the overhead in the tunnels.  One might hope they'll be clever enough, and sufficiently resourced, to get on with the plain line sections at the same time whilst they have these possessions (I live in hope but experience to date has shown they have not been very good at taking advantage of possession opportunities).

 

https://www.gwr.com/travel-updates/planned-engineering

 

As far as the GWML overhead is concerned I think we need to bear in mind several factors - firstly it would appear to be intended to be 'stiffer' (in deflection terms) than previous UK catenary  presumably for higher speed twin panto operation - as is also the case on the SNCF LGVs of course where much higher pan uplift forces are used than has ever been the case in the UK.  Secondly there appear to have been concerns about reliability in, particularly, strong winds fed into the spec which has presumably contributed to the more 'imposing' masts being used in many places (but not all as lots of single line masts are no different from traditional BR 25KV single line masts and are actually a lot neater than those in terms of registration arm design).

 

I also wonder if experience with the Eurostar tests on ECML catenary have possibly played a part in the sort of specification that was fed into the design process?

[phil-b259]

I heard somewhere that if they have to run a pair of 800s with one of the inner pans raised for any reason, they'll be limited to less than 125.

No idea if it's true or not, or whether it's applicable to the GWML or ECML.

 

Probably does and sounds logical when you consider that EMUs like the Deserios can only reach 110mph but will have closely spaced pantographs when working in multiple.

[rodent279]

So no >200km/h on lines not specially built for high-speed in Europe as far as we know?

 

I raise this because the difference between upgrading & electrifying an existing mainline that is the thick end of 200 years old, and building a new railway dedicated to high speed passenger trains, is that it is possible on new build lines to keep the contact wire at a virtually constant height above rail level. That will be much more difficult on an existing railway, if not impossible. I think on the WCML the allowable height variation is something like 4ft.

[robertcwp]

So no >200km/h on lines not specially built for high-speed in Europe as far as we know?

 

I raise this because the difference between upgrading & electrifying an existing mainline that is the thick end of 200 years old, and building a new railway dedicated to high speed passenger trains, is that it is possible on new build lines to keep the contact wire at a virtually constant height above rail level. That will be much more difficult on an existing railway, if not impossible. I think on the WCML the allowable height variation is something like 4ft.

I thought TGVs had run at over 200 km/h on the classic line south of Tours before the high-speed line was extended to Bordeaux, possibly up to 220 km/h.

[Edwin_m]

I thought TGVs had run at over 200 km/h on the classic line south of Tours before the high-speed line was extended to Bordeaux, possibly up to 220 km/h.

I think I've heard that too but don't have a source. 

 

According to Wikipedia Amtrak's Acela Express runs at up to 240km/h.  It is entirely on "classic" infrastructure. 

[Hellzapoppin]

I wonder if it's being referred to 'inside' as 're-quadrification'?  Mind you I wonder if there are actually any senior people on the Zone who were about (or even born?) at the time of the 'de-quadrification' as it was called back in the 1980s?  

 

Sometimes I get this sense of 'I counted them all out and I counted them all back' with some of these re-quadrification schemes where I seem to have started the ball rolling with my scheme to put back the Relief Lines been Wantage Road and Challow back in the 1990s (although I very purposely didn't call it re-quadrification but presented it, quite accurately, as dynamic loops - complete with the graphs to prove that).

 

Edit to correct typo.

To answer your question about senior people remembering the layout as was in the 80s, yes there are and it's simply known as 4 tracking.

[jyte]

I think I've heard that too but don't have a source. 

 

According to Wikipedia Amtrak's Acela Express runs at up to 240km/h.  It is entirely on "classic" infrastructure. 

This is true.

 

(Going to go off topic for a bit, sorry!) 

 

However, the Acela only reaches 150mph (240kph) for a grand total of 30 miles in Rhode Island. It's otherwise slower with the rest of the more recently electrified "Northern" section from New York-Boston limited by its ridiculously curvaceous coast following route (think Dawlish) and the Southern half limited by electrification equipment dating back to about 1910 that makes the ECML catenary look incredibly reliable and that Amtrak just cannot afford to widespread replace.

 

That being said the bits of the NEC where Acela reaches 240km/h have been upgraded just about as much as they physically can be to be a high speed line without actually being a new built high speed line. There's cab signalling, continuously welded rail, independently registered catenary, a 25kvAC power system and no at grade crossings. 

[Edwin_m]

I've been told, by someone that ought to know, that speeds on classic UK infrastructure won't ever go much above 225km/h because the aerodynamic forces between two passing trains would dislodge the ballast.  This may be less of a problem elsewhere where the tracks are more widely spaced (though the trains are also bigger) and I guess slab track might offer an alternative solution. 

 

Increasing the track spacing would require re-build of at least half the track, stations, signals and OLE and probably nearly all the structures. 

[Geoff Endacott]

I guess slab track might offer an alternative solution...

 

...or lots of glue.

 

Geoff Endacott

[Hellzapoppin]

In some areas the ballast is glued, Dawlish being one of them.

[RJS1977]

...or lots of glue.

 

Geoff Endacott

 

Don't forget the washing-up liquid!

[Ron Ron Ron]

In some areas the ballast is glued, Dawlish being one of them.

 

 

That must be why it gets washed away when diluted by lots of sea water.

They should try Copydex instead.

 

 

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