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Great Western Electrification Progress

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Mordac

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Pedantically, it is the track, and the signalling, and the underbridges, and the earthworks, and the level crossings, and the staff safety arrangements, and ... I’ll stop boring you all...
Well, I'll defer to your knowledge, but I did think the track in at least parts of the GWML would be good for 140mph running if the signalling was there.
 
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There is some construction work for masts at the west end of platforms 1 & 2 at Cardiff Central.

3 masts appeared on Platform 0 just before Christmas.
 

59CosG95

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There is some construction work for masts at the west end of platforms 1 & 2 at Cardiff Central.

3 masts appeared on Platform 0 just before Christmas.
Thanks very much for that Paul! Adding that into the changelog.

Much like the Blackpool - Manchester wiring thread, I'll keep track of any changes from now on in. I'll post changelogs every Monday; changes will be in red.
 
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jyte

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Well, I'll defer to your knowledge, but I did think the track in at least parts of the GWML would be good for 140mph running if the signalling was there.
The alignment is there, I think the track and ballast would need some work for 140mph iirc.
 

edwin_m

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The alignment is there, I think the track and ballast would need some work for 140mph iirc.
Parts of it would be OK, but some investigation and design work would be needed to work out which parts. Then it might turn out that the answer is "all the straights but none of the curves", which would result in site work being needed practically everywhere.
 

Grumpy

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I don't understand the ongoing fascination re running at 140 mph on the GWML. With the best will you are unlikely to be able to get much more than 40-50 miles of increased speed which might save approx. 2 minutes. It just wouldn't be worth the initial and ongoing costs together with loss of paths.
This fascination is one of the main reasons why this project has turned into such a mess. Apart from the rolling stock cost, specifying the electrification requirement to cope with multiple pantographs at 140mph led to the ludicrous costly system installed which in turn killed off electrification elsewhere.
 

bastien

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Pedantically, it is the track, and the signalling, and the underbridges, and the earthworks, and the level crossings, and the staff safety arrangements, and ... I’ll stop boring you all...

Well the APT-E did 150+ years ago, so it should be fine! ;)
 

bastien

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I don't understand the ongoing fascination re running at 140 mph on the GWML. With the best will you are unlikely to be able to get much more than 40-50 miles of increased speed which might save approx. 2 minutes. It just wouldn't be worth the initial and ongoing costs together with loss of paths.
This fascination is one of the main reasons why this project has turned into such a mess. Apart from the rolling stock cost, specifying the electrification requirement to cope with multiple pantographs at 140mph led to the ludicrous costly system installed which in turn killed off electrification elsewhere.

What's really nuts is that they specified all that for parts of the line that could never get to 140mph anyway!
 

cle

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I don't understand the ongoing fascination re running at 140 mph on the GWML. With the best will you are unlikely to be able to get much more than 40-50 miles of increased speed which might save approx. 2 minutes. It just wouldn't be worth the initial and ongoing costs together with loss of paths.
This fascination is one of the main reasons why this project has turned into such a mess. Apart from the rolling stock cost, specifying the electrification requirement to cope with multiple pantographs at 140mph led to the ludicrous costly system installed which in turn killed off electrification elsewhere.

Are the non-stop Bristol Parkway trains not in some shape or form, possibly intended to be Plymouth and Penzance trains of the future? I'm sure i read a while back that once wired and 140mph running, via Bristol would be quicker than B&H. And surely with this stopping patterns (and wires/140 to Taunton) - the time savings would be greater?
 

HowardGWR

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I think if you read earlier posts, this is temporary solution involving a significant speed restriction as the catenary height is dropped from LC to the bridge.
Thanks very much. I had, but had missed the point about a lower speed limit. Is it known what that lower speed limit is please?
 

HowardGWR

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Pedantically, it is the track, and the signalling, and the underbridges, and the earthworks, and the level crossings, and the staff safety arrangements, and ... I’ll stop boring you all...
No. it's not boring at all. Perhaps you have a link to a document about that. The problem about via Bristol at 140 mph being quicker than the B and H route, is also that they removed the link from the SPM avoiding line to the Bath line, so that trains have to go through Temple Meads from Taunton to get to Bath. However they can use the SPM line to get to the Badminton line. That will have more 125 stretches.
 

D1009

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No. it's not boring at all. Perhaps you have a link to a document about that. The problem about via Bristol at 140 mph being quicker than the B and H route, is also that they removed the link from the SPM avoiding line to the Bath line, so that trains have to go through Temple Meads from Taunton to get to Bath. However they can use the SPM line to get to the Badminton line. That will have more 125 stretches.
I can't see how running via SPM would be quicker than through Temple Meads, particularly when you consider the "Rhubarb curve" is limited to 10 mph. In the bad old days it was actually proposed to reroute all the West of England trains via Bristol. There simply isn't the capacity to do that these days
 

Sean Emmett

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A reality check before this gets too surreal. We need haste not speed.

Biggest savings come from raising the lowest speed limits.

So if you really are going to send Cornwall services via Badminton and the rhubarb curve (I can just imagine the press coverage!) then raising half a mile from 10 mph to 15 mph will save a minute - as much time as raising 19.5 miles from 125 to 140.

I made a similar point after the Tornado trip a year ago - lifting the 5 mph steam clearance slack through Bath (to the usual 40) would
have saved more time than allowing 90 mph or more down Dauntsey, if rather less fun.

Back in the real world, yes the overly restrictive limits out of PAD need sorting, ditto the 15 mph into plats 13/15 at BRI. Far better (and easier?) to do that than contemplate 140 mph running.
 
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Wychwood93

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A reality check before this gets too surreal. We need haste not speed.

Biggest savings come from raising the lowest speed limits.

So if you really are going to send Cornwall services via Badminton and the rhubarb curve (I can just imagine the press coverage!) then raising half a mile from 10 mph to 15 mph will save a minute - as much time as raising 19.5 miles from 125 to 140.

I made a similar point after the Tornado trip a year ago - lifting the 5 mph steam clearance slack through Bath would
have saved more time than allowing 90 mph or more down Dauntsey, if rather less fun.

Back in the real world, yes the overly restrictive limits out of PAD need sorting, ditto the 15 mph into plats 13/15 at BRI. Far better (and easier?) to do that than contemplate 140 mph running.
Whichever way you look at it, Cornwall via Badminton, rhubarb (did that on a diversion due C.Sodbury flooding - up through Chippenham at 125!) and SPM is not exactly 'eco'. Better to do incremental PSR upgrades on the B&H and incremental OHL stuff beyond Newbury. For the former cant may be an issue for stone (freight) traffic - cant and deficiency of same beyond that point something to look at. Cant deficiency in France much more than here.
 

GRALISTAIR

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A reality check before this gets too surreal. We need haste not speed.
Biggest savings come from raising the lowest speed limits.
So if you really are going to send Cornwall services via Badminton and the rhubarb curve (I can just imagine the press coverage!) then raising half a mile from 10 mph to 15 mph will save a minute - as much time as raising 19.5 miles from 125 to 140.

Exactly. Don't want to get too far OT, exactly the same on Manchester - Stalybridge- Leeds -York TPE electrification/route modernization. I may even upload the graph here. The famous comment - "You don't need to go fast - just avoid going slow"!!
 

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Bald Rick

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No. it's not boring at all. Perhaps you have a link to a document about that.

There is a NR standard about raising linespeeds, but I don’t have a link to it. But it does make the point (which I have re-made on this forum several times) that there are 80+ factors that can affect linespeed, of which track geometry is but one.

In this example, a key issue about going over 125mph is that discontinuities in the track are not permitted. That means every set of points must have swing nose crossings. A second key issue is that all types of level crossing are forbidden and must be closed. A third is that >125 is not permitted alongside platforms that are open to the public.

As others have said, far more benefit (including fuel efficiency and brake wear) can be gained from removing lower speed dips in the profile than pushing the top end.
 

D1009

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A reality check before this gets too surreal. We need haste not speed.

Biggest savings come from raising the lowest speed limits.

So if you really are going to send Cornwall services via Badminton and the rhubarb curve (I can just imagine the press coverage!) then raising half a mile from 10 mph to 15 mph will save a minute - as much time as raising 19.5 miles from 125 to 140.

I made a similar point after the Tornado trip a year ago - lifting the 5 mph steam clearance slack through Bath (to the usual 40) would
have saved more time than allowing 90 mph or more down Dauntsey, if rather less fun.

Back in the real world, yes the overly restrictive limits out of PAD need sorting, ditto the 15 mph into plats 13/15 at BRI. Far better (and easier?) to do that than contemplate 140 mph running.
Whichever way you look at it, Cornwall via Badminton, rhubarb (did that on a diversion due C.Sodbury flooding - up through Chippenham at 125!) and SPM is not exactly 'eco'. Better to do incremental PSR upgrades on the B&H and incremental OHL stuff beyond Newbury. For the former cant may be an issue for stone (freight) traffic - cant and deficiency of same beyond that point something to look at. Cant deficiency in France much more than here.
I doubt that the severity of the Rhubarb curve would permit more than 10 mph anyway, and the pointwork into 13 and 15 at Temple Meads is certainly sharper than the rest of the station. Whether there is enough room to ease this given the physical constraints of the curvature of the whole layout as well as the bridges over the channels of the Avon is open to conjecture. As regards the Berks and Hants I was under the impression that the line speed improvements that took place in the 1980s were the maximum that could be achieved round the curves, though you may be able to get 125 on some of the straight bits.
 

HowardGWR

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St Philip's Marsh (GWR HST/DMU depot) Round the back of Temple Meads.
My apologies for the TLA. By the way, I was not advocating the Rhubarb link as a preferable route but good that it is available. It didn't use to be only 10 mph as far as I remember, so I don't know what happened to make it so low. There is a case for sending some future metro services direct from Bath to Abbey Wood. Lawrence Hill station would perhaps be a better stop point than Stapleton Road as bus services from there are frequent. I presume the Rhubarb will be electrified and also the avoiding line, when the deferred electrification completion takes place?
 

jyte

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I mean the B&H is pretty quick...it certainly feels like the quick part of a penz-pad run.

Also (and this has been discussed here before) a lot of the advantages of 140mph and wires via Bristol are eliminated by wires as far as Newbury. The B&H is geographically shorted by 20 something miles.

That being said: I was in a train that Penz-Pad train that travelled via Bristol (stopping at reading and Taunton) did the same timing as a non-stop through Taunton up B&H train (aka it was about 5 minutes faster than a Taunton stopping train would be) and slowed down to about 60mph through Didcot Parkway.

Regarding Phillips Marsh: If I have permission to get the Railforums standard issue crayons out...you could certainly get a nice 'Bristol bypass' built! Then again, if you're doing that why not bypass some of the infamous B&H curves like Crofton?
 

The Ham

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I would suggest that you'd get more bang for your buck by improvements West of Exeter (not least as it would also improve XC services).

If the Crofton curves are those to the west of Bedwyn then the railway follows the canal, which would mean crossing the canal to take a straighter line. Which although not insurmountable could suggest that there a good reason that both follow each other (possibly an obstruction like a big hill).
 

3973EXL

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Is that level crossing due for closure? Surely if it stayed users might tempted to abuse it if the extended turn back siding was occupied.

I believe the footpath has to be diverted before the siding can be extended.

Searching comes up with the following;

Rights of Way Public Path Orders
http://php.wiltshire.gov.uk/row/ppo/ppo_search.php
Great Bedwyn diversion for Safety application.
 

Unclepete

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Hi all,
photos from yesterday, ref the new PSU point at Boundry road bridge.
Things coming along nicely now.

PSU1.JPG PSU2.jpg PSU3.jpg
 

swt_passenger

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I believe the footpath has to be diverted before the siding can be extended.

Searching comes up with the following;

Rights of Way Public Path Orders
http://php.wiltshire.gov.uk/row/ppo/ppo_search.php
Great Bedwyn diversion for Safety application.

Nothing like as significant a job as sometimes described. Looks like no more than an extra 10 metres west.

Just looked at Google earth and their measuring tool suggests they really are only looking for the odd few metres extra length. The parallel or straight useable length of the siding is very nearly the notional 130m length of a 5 car IET already.
 
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59CosG95

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Hi all,
photos from yesterday, ref the new PSU point at Boundry road bridge.
Things coming along nicely now.

View attachment 43925 View attachment 43926 View attachment 43927
Fantastic capture there Pete - I've added the progress on the power supply front to the changelog, which I'll post on Monday morning.

Did the concrete pours look fairly recent from afar? I'm sure @GRALISTAIR can testify from the Blackpool-Manc wiring thread that similar "pour and cure" work has taken place at Lostock recently, and that 4 or so weeks needs to elapse before the substation is installed in situ.
It's worth mentioning that the next blockade on the B&H is 23/4 to 26/4 - perhaps that's there to allow the substation to be installed.
 
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