Great Western Electrification Progress

[DidcotDickie]

Went to the Uffington Show yesterday. Looks as though most of the steelwork Steventon - Wantage Road - Baulking is up and ready for wiring.This has been going on apace last few weeks.

All of the steelwork from west of Steventon to Baulking is now up and the line is wired throughout (and has been for some weeks). Most of the steelwork is complete from Baulking through to west of Acorn Bridge (where the line crosses the A420) - I'd say that over 90% of the main steelwork is in place and most of the small part steelwork too.

 

[veryoldbear]

All of the steelwork from west of Steventon to Baulking is now up and the line is wired throughout (and has been for some weeks). Most of the steelwork is complete from Baulking through to west of Acorn Bridge (where the line crosses the A420) - I'd say that over 90% of the main steelwork is in place and most of the small part steelwork too.

Many thanks. I was driving so saw the steelwork but didn't quite catch up with the wiring. BTW what is all the stuff just to the East of Wantage Road Bridge? Looks very complicated.

 

[DidcotDickie]

Many thanks. I was driving so saw the steelwork but didn't quite catch up with the wiring. BTW what is all the stuff just to the East of Wantage Road Bridge? Looks very complicated.

It's an autotransformer station (ATS), part of the power supply arrangements for the line. It looks complex with all the feed wires from the autotransformers and switches strung across the tracks to supply the traction OLE

There are three others on the Didcot-Swindon section just west of the site of Uffington station, at Shrivenham and also at Swindon, in the V between the main and Gloucester lines. Additionally there is the National Grid feeder at Foxhall Junction west of Didcot.

 

[swt_passenger]

The image from the NR blurb seems to imply that the widening will require some of the concrete that is to be demolished is from the recent-ish construction of the flyover and festival line. Is this correct.

Usual rubbish NR PR. The view in the photo is of a newly constructed underbridge that will eventually become dedicated to pedestrians and cyclists.

The widened and lowered road will run through a separate section of underbridge parallel to the one in the photo, and just to the west. It is already built, and sitting there behind hoardings. Google Street View from the north shows it clearly.

As coppercapped said, the work under the railway is all done. NR use words such as 'create new bridge' for something that has been there for ages. The work about to start is to modify the highway alignments at both ends to align with the new underbridge.

 

[snowball]

The widened and lowered road will run through a separate section of underbridge parallel to the one in the photo, and just to the west. It is already built, and sitting there behind hoardings. Google Street View from the north shows it clearly.

Here:

https://www.google.co.uk/maps/@51.4...31.335499&pitch=0&thumbfov=100!7i13312!8i6656

 

[DY444]

Swindon used to have a Down island platform on a loop off the Down Main. The Down platform loop adjacent to the Down Main rejoined the Down Main, the platform loop to the south of the platform was connected to what the GWR called the 'South Wales Main Line' but which is now the line to Kemble and Gloucester. This crossed the entire layout over a sequence of diamond crossings.

This platform was removed completely when Swindon was resignalled in the 1960s so ALL Down trains calling there had to cross to what was the Up line island platform, crossing the UP Main on the flat in the process. The now derelict office block on the Down side was build in that period right across the site of the GWR's Down island.

This wasn't so much of a problem when traffic densities were not so high, but with the traffic growth following privatisation the two crossings of the Up Main that a Down train had to make became a problem. The Strategic Rail Authority was the force for the building of a new Down line platform, but to minimise costs it was not placed on a loop as the earlier GWR arrangement but built directly against the Down Main.

It might not be ideal, but it is streets ahead of the situation previously.

I am not sure of the complete reason for the 85mph limit through the station now - the alignment seem suitable for higher speeds - but I suspect it is a combination of signal siting, track condition and inertia.

Isn't it good that some of us (a) lived through all this and (b) have reasonably good memories?

The 85mph limit dates from when the layout was changed at Rushey Platt to allow up stopping trains a faster run into the station.

 

[jimm]

As Jimm said, the work under the railway is all done. NR use words such as 'create new bridge' for something that has been there for ages. The work about to start is to modify the highway alignments at both ends to align with the new underbridge.

Credit is due to coppercapped, not me.

 

[swt_passenger]

Credit is due to coppercapped, not me.

Ta, fixed.

 

[Siemens Staines]

Usual rubbish NR PR. The view in the photo is of a newly constructed underbridge that will eventually become dedicated to pedestrians and cyclists.

The widened and lowered road will run through a separate section of underbridge parallel to the one in the photo, and just to the west. It is already built, and sitting there behind hoardings. Google Street View from the north shows it clearly.

As coppercapped said, the work under the railway is all done. NR use words such as 'create new bridge' for something that has been there for ages. The work about to start is to modify the highway alignments at both ends to align with the new underbridge.

Thank you all for the clarifications, it explains a lot. NR succeeded in pulling the wool over my eyes (not always difficult to do).

 

[snowball]

It's an autotransformer station (ATS), part of the power supply arrangements for the line. It looks complex with all the feed wires from the autotransformers and switches strung across the tracks to supply the traction OLE

There are three others on the Didcot-Swindon section just west of the site of Uffington station, at Shrivenham and also at Swindon, in the V between the main and Gloucester lines. Additionally there is the National Grid feeder at Foxhall Junction west of Didcot.

Seems close spacing, about every six miles. I think track sectioning cabins on the WCML are typically at about 14-mile intervals.

On second thoughts, maybe a better comparator on non-autotransformer lines is the spacing of booster transformers which I think are every couple of miles, so perhaps the GW is not so closely spaced from that point of view.

 

[3973EXL]

Some photos from around Reading today:

Platform 3 now has both insulators fitted.
West curve from Cow Lane, one line wired.
West curve bridge south side.
Feeder lines from Cow Lane, both wired.
West curve bridge north side.
Looking towards GWML and the single track Cow Lane bridge. The new under bridge is to the left behind the earth bank with the blue sign (what all the fuss has been about) after the entrance to the storage units.
Closer view looking under the Festival line & Flyover at the present route.
ATF gap east of the station on the downside, wire now up but not attached to the insulators yet.

 

[3973EXL]

Twyford today:

New DR signal off the end of plat 3 now in use, old signal removed.
Missing mast on plat 4 now up and wired.
Two views of wiring progress at Twyford ATS.
Southbury lane bridge.
ATF on the downside goes under Twyford bridge in troughing then under plat 1.
There has also been drainage work going on at the same time.
Two views of Twyford W progress, one finished, three to go.

 

[jimm]

Various pictures and video clips of work taking place during the blockade between Swindon and Bristol Parkway if you scroll through the Network Rail Western Twitter feed, including conductor rail being fitted inside Chipping Sudbury Tunnel.

https://twitter.com/networkrailwest

 

[Wilts Wanderer]

The 85mph limit dates from when the layout was changed at Rushey Platt to allow up stopping trains a faster run into the station.

It might date from then, but the reason for the speed restriction (actually 85/40) is because the passenger subway at Swindon station is structurally weak.

 

[SpacePhoenix]

It might date from then, but the reason for the speed restriction (actually 85/40) is because the passenger subway at Swindon station is structurally weak.

Can anything be done to reinforce the subway without rebuilding it?

 

[QueensCurve]

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

When did Swindon become 85mph and why?

I seem to recall part of the original justification for prioritising delivery of HSTs to the GWML was that only reading (then 80mph) required trains to slow below 125mph between Puddington and Chippenham.

 

[59CosG95]

Updates re Paddington P1/2: The headspans within the station for P1/2 are in (as we know). Both P1 & 2 have SPS on the outside canopies, and under the footbridge at the end of the trainshed, and P1 now has both Catenary and Contact wires in, along with signs warning about 25kV. Worth noting as well that the dropper wire (if that's the word) from the headspan to where the P2 catenary wire would go is currently cable-tied to the headspan; this will presumably come down when the wires reach P2.

Does anyone know when wires will reach P2?

 

[snowball]

When did Swindon become 85mph and why?

The "why" part is answered in the post two before yours.

 

[QueensCurve]

Thank you. Woulnt it be nice if Network rail and its contractor's managed to complete something early for a change. Would that be a first.
K

Norton Bridge Flyover was finished early - by about 18 months.

 

[QueensCurve]

To prevent passengers being swept off the platform by the backdraft of a passing train as once occurred at harpenden when a small person was thrown across the tracks after a passing HST at speed had been through and the person was standing on the edge.

But that platform was demolished and reinstated after many years.

Regarding the Harpenden incident when did that happen? Was that when the railway started painting the yellow lines on the platforms (late 70s as I recall)?

 

[QueensCurve]

This one never dies! :cry:

The issue is NOT the clearance under the bridge, but the rapid change in height of the contact wire from low (under the High Street bridge) to high (over the Stocks Lane level crossing).

Could the level of the road not be reduced?

 

[LNW-GW Joint]

Norton Bridge Flyover was finished early - by about 18 months.

But the whole "Stafford" scheme was originally part of WCRM and was repeatedly postponed from 2008 onwards.
Agreed it was a very successful execution of the job once started.
We are still waiting for the extra trains it enabled...

 

[snowball]

In the current Modern Railways the MD of Cross Country enthuses about the benefits Norton Bridge has brought.

 

[adrock1976]

Unsure if this would be a better fit in the Class 800 thread or not.

A thought that has come into my mind is that as the wires will at this moment in time be ending at Newbury for the Devon and Cornwall via Castle Cary route, has any thought been given in the event should the engines fail to start (from London) or the pantograph fails to rise (to London)?

I felt it would have been better to continue the wires to Westbury, as there is plenty of space to move the train out of the way if need be, so it does not block everything behind.

After all, we all know exactly what happens when the pantograph fails to rise or lower at Farringdon or City Thameslink i.e everything behind grinds to a halt with not much room for recovery.

 

[3973EXL]

Quick visit to Twyford this afternoon. Mains under possession with a RoadRailer working at the ATS.

Checked Southbury Lane bridge, plenty of scaffolding but no parapet work yet!

 

[swt_passenger]

Unsure if this would be a better fit in the Class 800 thread or not.

A thought that has come into my mind is that as the wires will at this moment in time be ending at Newbury for the Devon and Cornwall via Castle Cary route, has any thought been given in the event should the engines fail to start (from London) or the pantograph fails to rise (to London)?

It would be a question of all the diesel engines failing, on a train with either 3 or 5, or (if 2 x 5 cars in multiple) 6 engines. What's the real likelihood of total failure? In the up direction they'd just carry on on diesel if both pantographs failed.

It has been decided that Newbury is the optimum boundary for the regular EMU outer suburban services operated by 387s. There have already been numerous suggestions to extend the wires to Westbury, but I don't think anyone has previously suggested it as being the solution to mode change failures.

 

[jyte]

A thought that has come into my mind is that as the wires will at this moment in time be ending at Newbury for the Devon and Cornwall via Castle Cary route, has any thought been given in the event should the engines fail to start (from London) or the pantograph fails to rise (to London)?

I felt it would have been better to continue the wires to Westbury, as there is plenty of space to move the train out of the way if need be, so it does not block everything behind.

To build a bit on what swt_passenger said:

Extension to Westbury was considered. I don't think NR could get the Benefit:cost ratio better than 0.4:1 and that was with the old much more optimistic figures, electric freight and using the line as a fully electrified diversionary route. Maybe in 10 years if diesel costs a fortune the position will be different, but I suspect the DfT would rather have batteries fitted.

Regardless when the engines are fully rated, a 5 car 3 Engine 800 has something like 3000HP. In the event of an engine failure, my understanding from other members of this forum is that that the engines will automatically adjust to max power (its a software thing) giving a 5car class 800 with 1 failed engine 2000hp. They've teen tested with a simulated engine failure (I believe) and the result was 'take it out of service soon' performance but not dire.

2000hp is the power of a single HST power car and a 5 car 800 is I imagine quite a bit lighter.

 

[JN114]

It might date from then, but the reason for the speed restriction (actually 85/40) is because the passenger subway at Swindon station is structurally weak.

The 85 through Swindon dates from well before the "passengerisation" of the Up Goods at Rushey Platt (late 80s vs mid 00s)

The reason that had been bandied around was it was due to BR cost cutting. Lowering the line speed through the station allowed the point work to be dropped down to a lower maintenance regime, and thus save BR money. When stopping the majority of passenger trains at Swindon became the norm in the late 80s, they couldn't justify maintaining the points for a speed only a small handful of trains attained through the area. 90mph - the speed of the majority of the non-stop (mail) traffic - was still in the higher maintenance tier so 85 was selected.

The /40 came along much later, and could believably be resultant of the subway conditions.

There are plenty of examples of PSRs for the length of a weak structure, but the 85 starts at Highworth on the Down and Rushey Platt on the Up, conveniently where all the Swindon area pointwork starts.

 

[snowball]

Could the level of the road not be reduced?

When you say the road do you mean the railway?

 

[83G/84D]

Wires from Maidenhead to Tilehurst apparently going live on 16th September.