Great Western Electrification Progress

[absolutelymilk]

There is the potential for 140mph operation but the DfT will still have to decide, when all the required elements are in place, notably once ETCS cab signalling is operational, whether it wants to foot the bills that 140mph will bring, in terms of extra energy use and train maintenance bills, for example, but also extra infrastructure that may be required to clear the way for IETs to belt along at 140mph.

It may even improve capacity if they choose to use it only for late-running trains?

 

[mr_jrt]

Was the stretch from Didcot to Swindon ever 4 tracked in its entirety? I can see in places that it would have been, but Steventon and Uffington both have bridges that look like they would have only ever spanned two tracks.

Nope. Circa 1900 didn't even have loops according to NLS.

 

[Envoy]

I am amazed that future proofing any new structures to allow for 4 tracking at some point in the future has/is not being done. Who knows, we could even see an Ipswich> Cambridge> Oxford>Swindon> Bath> Bristol service at some point in the future.

If 140mph running across southern England became possible, it would surely induce more people to use the trains rather than the M4.

 

[DidcotDickie]

Nope. Circa 1900 didn't even have loops according to NLS.

Correct. The long loops between Challow and Wantage Road were put in first during the 1930s, removed during the 1960s MAS resignalling programme and put back in around 1990. There were also loops at Uffington (disused from sometime in the 1990s) and Knighton (decommissioned in the 1960s I think).

Probably others nearer Swindon too, but the Didcot to Swindon section was never wholly four track.

 

[alxndr]

4 tracking may be somewhat difficult between Uffington and Bourton, judging by the positioning of a lot of the electrification masts. They appear to mostly be in the ground where the track would go.

There's a fair gap between Ashbury-Knighton on the up side where you could possibly squeeze in another track, but definitely not two.

 

[DidcotDickie]

There's a fair gap between Ashbury-Knighton on the up side where you could possibly squeeze in another track, but definitely not two.

Yes, that's where the Knighton loop was. On the up side only I believe.

 

[Hophead]

I am amazed that future proofing any new structures to allow for 4 tracking at some point in the future has/is not being done. Who knows, we could even see an Ipswich> Cambridge> Oxford>Swindon> Bath> Bristol service at some point in the future.

If 140mph running across southern England became possible, it would surely induce more people to use the trains rather than the M4.

The scheme is so wildly over budget and behind schedule that no-one is going to be expanding the scope any time soon.

 

[mr_jrt]

I went and had a bit of a dig through NLS's maps and found some from the 30s that show all the extra tracks. Very interesting just how long those loops were:

From east of Shrivenham Station, to Knighton Copse, though the widened formation appears to run almost to Uffingham.

...and from east of Challow Station, to west of Wantage Road Station.

...I could sit and work it out, but off the cuff that's surely got to mean at least half of the line between Didcot and Swindon was effectively 3-tracked?

PS, couldn't find any similar built loop near Uffington, unless the one from Shrivenham was extended after the map was drawn up? Regardless, all very interesting.

 

[Chris125]

I am amazed that future proofing any new structures to allow for 4 tracking at some point in the future has/is not being done. Who knows, we could even see an Ipswich> Cambridge> Oxford>Swindon> Bath> Bristol service at some point in the future.

Your assuming that 4 tracking would involve building extra tracks directly alongside the existing line; given the massive cost and disruption that comes with working on the existing network it seems more likely they'd be (at least partially) on a separate alignment - perhaps with higher linespeeds to justify the cost.

 

[edwin_m]

Any scope to send more of the freight via Westbury instead?

 

[steverailer]

I am amazed that future proofing any new structures to allow for 4 tracking at some point in the future has/is not being done. Who knows, we could even see an Ipswich> Cambridge> Oxford>Swindon> Bath> Bristol service at some point in the future.

If 140mph running across southern England became possible, it would surely induce more people to use the trains rather than the M4.

That would have put the cost even further over budget, in some places they don't own the land to allow this, added to the fact that I don't think that there would be the machinery available with the reach from track to install the piles and masts.

It would also mean that the entire route would have portal structures, massively increasing the cost and time taken

 

[veryoldbear]

Two, three, four.

Presumably the track bed and bridges for much of the GW was for broad gauge. How would width compare overall? How much extra real estate would four tracking actually take up?

 

[jyte]

Any scope to send more of the freight via Westbury instead?

Probably. I think the mendip quarry trains use 1p2h in each direction and there's not much other freight over the line. A problem might be the B&H has pretty mixed traffic as far as Newbury with slow stoppers plus hourly stoppers as far as Bedwyn, the busy flat Souchcote Flat junction with 2x hourly Cross Country services, hourly+ freight services, 2x hourly services to Basingstoke.

It's not helped by the fact the B&H has an average linespeed of about 95mph with no passing provision in the down direction after Newbury until you reach Woodborough (some 25 miles), and the next passing provision after that involving crossing the up-line to Westbury (a further 17 miles). I travel the B&H pretty frequently and whilst trains aren't frequently delayed by freight services, the delays can be 20-30mins+ if you get stuck behind one.

I think the NR RUS has a mention of improving services to allow for 1 quarry freight path an hour - I suspect the B&H could take some extra freight (slotted in behind a stopper to Exeter?) but probably not all the freight that does Didcot-Swindon.

 

[HowardGWR]

Remember my point about the Steventon bridge was about future proofing of that bridge, not anything else. The '10 foot' of the reduced broad gauge allows for a central pillar for a wider bridge.

Of course, future 4 tracking would involve a considerable project, but at least it would not involve this bridge so much.

I believe the same mistake has been made east of Swindon with that bridge there, recently altered, but I'm not so sure on that one, looking at the Google Earth photos.

 

[starlightEXPRESS]

You're assuming that 4 tracking would involve building extra tracks directly alongside the existing line; given the massive cost and disruption that comes with working on the existing network it seems more likely they'd be (at least partially) on a separate alignment - perhaps with higher linespeeds to justify the cost.

You could easily envisage a new High Speed line leaving the GWML at Pangbourne and running mostly south of the M4 to Wootton Bassett. (Would be around 35-40 route miles, cutting out Didcot (including the flat junction to Oxford) and Swindon, which would be left on the 'classic' GWML. HS4 anyone?

 

[JN114]

So looking at a vaguely sensible alignment, that avoids carving up any of the West Berkshire villages -

http://imgur.com/a/BzfvI

(Satellite imagery courtesy of Google)

60.62km, 728 seconds at 300 km/h (via "new" High Speed diversion)

vs

66.57km, 1192 seconds at 200 km/h (via existing Main Line)

Gives a grand total saving of 464 seconds journey time.

Using HS2 estimates as a benchmark the likely costs for such a scheme would be in the range of £1-1.5bn, never mind new rolling stock etc capable of exploiting the new infrastructure.

Such an alignment would avoid both Didcot and Swindon stations, both of which are quite busy with London commuter traffic. It would also still ultimately feed into a 2 track bottleneck at Wootton Bassett Jn.

***

Bottom line is, freight pathing between Didcot and Swindon really isn't a capacity constraint. Don't forget the existing service level between the points is significantly less than what was extant 10-15 years ago, when not only were there very regular heavy coal trains trundling back and forth between Avonmouth and Didcot Power Station, but the 90mph Oxford to Bristol TM turbos as well.

Even reinstatement of additional loops is probably overkill. If the existing connection from the Down Main to the Down Goods at Highworth was raised up in to the 60-75mph bracket, it would save freights being brought to a crawl to use it - at the moment it's often better to allow the freight to run to Bassett because it will pull a long way ahead while the catching HST does station duties at Swindon.

The key to unlocking a lot of capacity on the GW west of Reading is timetabling. The present clockface 15 minute service doesn't lend itself well to creating additional paths. If, as often seen on Sundays, the South Wales was flighted right behind (or ahead of) the Bristol, you would have 26 minutes free space behind the South Wales between Didcot and Swindon to fill with all manner of new services and freight trains.

 

[veryoldbear]

Unfortunately the "vaguely sensible alignment" goes right through some rather spectacular downland, that would require extensive cuttings and tunnels, and the costs would be incredible.

 

[Envoy]

So looking at a vaguely sensible alignment, that avoids carving up any of the West Berkshire villages -

http://imgur.com/a/BzfvI

(Satellite imagery courtesy of Google)

60.62km, 728 seconds at 300 km/h (via "new" High Speed diversion)

vs

66.57km, 1192 seconds at 200 km/h (via existing Main Line)

Gives a grand total saving of 464 seconds journey time.

Using HS2 estimates as a benchmark the likely costs for such a scheme would be in the range of £1-1.5bn, never mind new rolling stock etc capable of exploiting the new infrastructure.

Such an alignment would avoid both Didcot and Swindon stations, both of which are quite busy with London commuter traffic. It would also still ultimately feed into a 2 track bottleneck at Wootton Bassett Jn.

***

Bottom line is, freight pathing between Didcot and Swindon really isn't a capacity constraint. Don't forget the existing service level between the points is significantly less than what was extant 10-15 years ago, when not only were there very regular heavy coal trains trundling back and forth between Avonmouth and Didcot Power Station, but the 90mph Oxford to Bristol TM turbos as well.

Even reinstatement of additional loops is probably overkill. If the existing connection from the Down Main to the Down Goods at Highworth was raised up in to the 60-75mph bracket, it would save freights being brought to a crawl to use it - at the moment it's often better to allow the freight to run to Bassett because it will pull a long way ahead while the catching HST does station duties at Swindon.

The key to unlocking a lot of capacity on the GW west of Reading is timetabling. The present clockface 15 minute service doesn't lend itself well to creating additional paths. If, as often seen on Sundays, the South Wales was flighted right behind (or ahead of) the Bristol, you would have 26 minutes free space behind the South Wales between Didcot and Swindon to fill with all manner of new services and freight trains.

That alignment is surely not logical as it goes up onto the high ground of the downs - with all their undulations - as can be gauged by driving along the M4. That is the reason why Brunel took the more level route to the north.

 

[HowardGWR]

That alignment is surely not logical as it goes up onto the high ground of the downs - with all their undulations - as can be gauged by driving along the M4. That is the reason why Brunel took the more level route to the north.

More importantly nowadays, is the acronym AONB. I don't know how the M4 got through the Berkshire Downs area, but it was at a time when countryside protection was as important as protecting town centres from irresponsible out-of-town retail development - so not important at all.

I am afraid this thread has departed from 'progress'. I opened a thread on GWML modernisation way back and I think this subject would possibly perhaps be more appropriate there.
http://www.railforums.co.uk/showthread.php?t=141916&highlight=Great+western

Edit: sorry the mods closed it.

 

[jimm]

Pictures have been posted over on RMweb of progress near Wootton Bassett, lots of masts and portals up, and small part steelwork as well, so wiring here may not be too far off now.

http://www.rmweb.co.uk/community/index.php?/topic/78877-gwml-electification/?p=2830666

 

[33Hz]

That alignment is surely not logical as it goes up onto the high ground of the downs - with all their undulations - as can be gauged by driving along the M4. That is the reason why Brunel took the more level route to the north.

Anyone remember when FGW proposed such a route, sometime around 15 years ago?

 

[jyte]

So looking at a vaguely sensible alignment, that avoids carving up any of the West Berkshire villages -

http://imgur.com/a/BzfvI

(Satellite imagery courtesy of Google)

60.62km, 728 seconds at 300 km/h (via "new" High Speed diversion)

vs

66.57km, 1192 seconds at 200 km/h (via existing Main Line)

Gives a grand total saving of 464 seconds journey time.

Isn't the line speed through Swindon 85? By bypassing it you'd not only

1) Force less trains to stop which would save a few minutes

2) Bypass the 85 section and the time lost from slowing from 125-85 then going back up to 125.

Even so it seems like a considerable cost to deliver negligible benefits. I'm pretty sure NR decided that 160mph+ running on the GW wasn't commercially viable due to need to path freight and the distance between some of the stations being shorter.

 

[alxndr]

Isn't the line speed through Swindon 85? By bypassing it you'd not only

1) Force less trains to stop which would save a few minutes

2) Bypass the 85 section and the time lost from slowing from 125-85 then going back up to 125.

There's a small section through Swindon station that's 85mph, yes.

 

[SpacePhoenix]

There's a small section through Swindon station that's 85mph, yes.

What's the reason for the drop to 85mph through Swindon?

 

[superkev]

I'm lost in terms of progress. Do we have any dates for energisation to Reading; Swindon and beyond.
Thanks
K

 

[coppercapped]

I'm lost in terms of progress. Do we have any dates for energisation to Reading; Swindon and beyond.
Thanks
K

Yes.

 

[Mag_seven]

I'm lost in terms of progress. Do we have any dates for energisation to Reading; Swindon and beyond.
Thanks
K

Are you the Project Director for this job?

 

[jyte]

Kev, if you want a rough answer, Reading area (thus Maidenhead to Didcot) is due to be energised during the 16th-18th September 2017 Reading Blockade with the first through electric services starting early 2018(?).

Didcot - Swindon is another kettle of fish more work still due - late 2018 might even be a bit optimistic!

 

[Mordac]

Kev, if you want a rough answer, Reading area (thus Maidenhead to Didcot) is due to be energised during the 16th-18th September 2017 Reading Blockade with the first through electric services starting early 2018(?).

Didcot - Swindon is another kettle of fish with major clearance work (a bridge replacement) still due - late 2018 might even be a bit optimistic!

They're not joking about this thread being stuck on groundhog day.

 

[coppercapped]

Kev, if you want a rough answer, Reading area (thus Maidenhead to Didcot) is due to be energised during the 16th-18th September 2017 Reading Blockade with the first through electric services starting early 2018(?).

Didcot - Swindon is another kettle of fish with major clearance work (a bridge replacement) still due - late 2018 might even be a bit optimistic!

Again, the Steventon bridge is NOT BEING REPLACED before the wires are up an energised.

(I think I have posted this before - quite recently...!)

Groundhog Day it is!