Great Western Electrification Progress

[Thatcham Xing]

Deltic, I live in B&H-land (within the stretch that will be wired east of Newbury), and can say that the ending of the wires at Newbury, and the originally-proposed services changes have been a big issue in these parts. Electric-only trains to Newbury, and then a DMU shuttle to the 3 stations further west was seen (and would have been) a fairly significant degradation of the service, which currently has those locations served by hourly semi-fast trains to and from Paddington all day.

Once we knew that the wires would end at Newbury, and then that all the 800's would be hybrid's, this seemed like the obvious, pragmatic solution. If you were paying about £5k per annum for a (for example) Hungerford to Paddington season ticket I'm sure you'd agree.

I can't comment further on your claims re. increased diesel engine wear as I have no knowledge of the technical aspects.

 

[Mag_seven]

Are you sure that this is correct? A drawing made by ABB - which I downloaded but failed to note its source URL - of the feeder arrangements shows the Didcot Autotransformer Feeder Site (taking its supply from the 400kV grid there) supplying the stretch from Maidenhead to Wootton Bassett. The Wootton Bassett ATFS takes its supply at 50kV from the Melksham 400kV grid supply point and feeds through to Westerleigh Junction and the Filton complex with the Thingley ATFS covering the stretch around Thingley and eventually through to Temple Meads.

So it looks quite possible that Didcot to Swindon can be fed in advance of the completion of the other works to the west. It is, after all, how it is intended to work on completion as there will be a SATS at Swindon.

You may be correct but my simplistic mind states that Didcot ATS cannot feed anything west of Steventon due to the gap there which means that Swindon can only be fed from the next feeding point along from Didcot which is Wootton Bassett. Unless of course what they mean by "Didcot-Swindon" is actually "Steventon-Wootton Bassett"?

 

[swt_passenger]

You may be correct but my simplistic mind states that Didcot ATS cannot feed anything west of Steventon due to the gap there which means that Swindon can only be fed from the next feeding point along from Didcot which is Wootton Bassett. Unless of course what they mean by "Didcot-Swindon" is actually "Steventon-Wootton Bassett"?

Even if there really is to be a physical gap in the catenary at Steventon, (which I believe is very doubtful - more likely to be a speed restriction or a neutral section), it doesn’t follow that there will be an electrical gap in the overall distribution function of the OHLE.

There are already many cases where the ATF switches to insulated cable in trunking under bridges, and through some stations, they could do the same to connect the live catenary either side of the bridge as well.

 

[Peter Sarf]

There may be an OLE gap there, or a steep wire gradient with a speed restriction for anything passing through with pans up. As 387s won't go west of Didcot the electric trains will all be 80x which can run through on diesel or even better coast through and only start the diesel if they get stranded.

Remember also, as seen with previous sections of GWML, that the official energisation date is only the date from which the OLE should be regarded as live. It may not even be live, and won't be ready to run trains until some time afterwards.

Occurs to me why not lower the track under Steventon bridge and do any other bodges required then REPLACE the level crossing with a bridge thus not requiring the wires to be so high at that point. Two advantages would be avoiding a sharp gradient in the witres (relative to the track) while eliminating a level crossing. Can reward the locals by thumbing a severe weight restriction on the old bridge - not the railways problem.

Or put a severe height restriction on the crossing - with thumping great girders to remind the dozey car drivers.

[/Simplistic-Ramble]

You may be correct but my simplistic mind states that Didcot ATS cannot feed anything west of Steventon due to the gap there which means that Swindon can only be fed from the next feeding point along from Didcot which is Wootton Bassett. Unless of course what they mean by "Didcot-Swindon" is actually "Steventon-Wootton Bassett"?

The Auto Transformer Wires can go up-high, down-low-a-bit or through a pipe as much as they like. The train's panto-graph does not touch them.

 

[w1bbl3]

Occurs to me why not lower the track under Steventon bridge and do any other bodges required then REPLACE the level crossing with a bridge thus not requiring the wires to be so high at that point. Two advantages would be avoiding a sharp gradient in the witres (relative to the track) while eliminating a level crossing.

The problem with over-bridging the level crossing is that houses are located so near to the crossing that embankments would not be possible. I'm sure this has been raised in the thread previously. In many respects the crossing should be closed, but it serves an important use locally.

 

[snowball]

You would have to raise the road from which this view is taken, so the houses on the left would probably be for the chop.

https://www.google.co.uk/maps/@51.6...4!1siFSJeN6-s3buHrhRM_fcAg!2e0!7i13312!8i6656

Also there's another level crossing a bit further west. Ideally you would try to replace both LCs with one bridge but it's difficult to see where to put it without demolishing houses for either the bridge or approach roads.

As for a height restriction, how would you maintain access to the buildings south of the line?

 

[Peter Sarf]

You would have to raise the road from which this view is taken, so the houses on the left would probably be for the chop.

https://www.google.co.uk/maps/@51.6...4!1siFSJeN6-s3buHrhRM_fcAg!2e0!7i13312!8i6656

Also there's another level crossing a bit further west. Ideally you would try to replace both LCs with one bridge but it's difficult to see where to put it without demolishing houses for either the bridge or approach roads.

As for a height restriction, how would you maintain access to the buildings south of the line?

Hmm. Looking at the streetview a narrow single lane bridge would fit especially with walls instead of embankments. How much traffic is there ?. The more traffic there is then the more likely it is that there is an alternative route. The more traffic there is the more need there is for a bridge. If not much traffic then no need for a big bridge. One less level crossing improves safety. I would suggest an underpass but there is that pesky stream nearby !.

Start a campaign - Steventon deserves a ring road !.

EDIT.
Actually looking at the map of the area I see the two crossing are to the West of the bridge. There is very little to the South of the two crossings and no through route beyond to anywhere. I note that both crossings are linked by roads both north and South so why have to level crossings ?. Close the level crossing nearest to the bridge - that is Stocks Lane. I also notice there is a small track running Eastwards to the road bridge - how about widening that thus obviating the need for either level crossing.

http://www.streetmap.co.uk/map.srf?...fordshire+[Town]&searchp=ids.srf&mapp=map.srf

Streetmap.co.uk is rather useful and you can zoom in for more detail.

 

[jimm]

Through Cotswold services do not stop at every station on every service. Even if they did, my argument is about cost of short distances only beyond the wires on diesel causing rapid wear to the diesel engines v. extending the overheads.
800s were not originally planned for B&H commuter services. It is a way out of avoiding the wrath of commuters west of Newbury having to change trains in the original plan. This cock-up could only happen in the UK.
Pity commuters living either side of Ormskirk cannot exert the same pressure for through services and new IC trains but they are only Northerners.

Have you actually looked at a Cotswold Line timetable? A limited number of services skip a limited number of stops (I am not counting the Oxfordshire halts) but that's it. Most, the Cathedrals Express included, make seven intermediate calls between Oxford and Worcester in the space of 60 miles. West of Worcester there are also short intervals between stops, combined with some stiff climbs in the Malvern hills.

That is a punishing cycle of work for any diesel engine, be it above the floor in an HST, or under it in an 800. If the engines can cope with that kind of treatment, I fail to see why going to Bedwyn suddenly takes them into some zone where they will fall to bits. Perhaps the people at Rolls Royce-MTU who build the engines might have said something about the idea of doing Newbury-Bedwyn and back, interspersed with lots of electric running, if they were worried it would destroy them?

800s were planned from the off for use on a number of Berks & Hants line semi-fast services, which in the peaks are a key part of the commuter services provided by GWR - such as the current HSTs from Westbury and Frome which provide the 06.29 and 06.45 services from Bedwyn to London and the 17.07 and 18.07 from Paddington to Frome and the 18.33 to Exeter.

And if "this cock-up could only happen in the UK" - what a tired old cliche that is - why on earth has SNCF bought several hundred bi-mode and bi-mode, bi-current trains for use in France in recent years? Why did the Spanish modify Talgo high-speed electric units with diesel generator cars so they can work beyond with wires? Must be some cock-ups on the Continent too.

 

[coppercapped]

You may be correct but my simplistic mind states that Didcot ATS cannot feed anything west of Steventon due to the gap there which means that Swindon can only be fed from the next feeding point along from Didcot which is Wootton Bassett. Unless of course what they mean by "Didcot-Swindon" is actually "Steventon-Wootton Bassett"?

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.

800s were not designed for commuter work in diesel mode. They were designed for 140mph long distance InterCity work on 25kv electric.
Fitting with underfloor power units required redesigning the bodyshell to accept them.
Whether heating up in service or preheated, repeated heating and cooling for short repeated cycles will cause rapid wear leading to failure. That is the nature of cast metal.

Modern engine design is very tolerant to operation outside the optimum conditions.

Fatigue cracking of engine castings due to temperature cycling is not unknown but generally is only significant after a very long life - the temperature difference is, at the most, from several Celsius degrees below zero to a maximum of 100 degrees as the coolant, being mainly water, won't get hotter without boiling. This is not an especially large temperature range for cycling castings. The cylinder liners and pistons obviously encounter a much wider temperature range but the liners are steel and aluminium pistons have been used in internal combustion engines since the Bentley Rotary - the problems are pretty well understood by now and engineered out.

Fatigue cracking due to stress reversals caused by combustion or the forces acting on crankshafts, connecting rods and pistons obviously does still occur - but good design and selection of materials pushes this out to tens if not hundreds of millions of cycles - which can be translated as years of use.

Wear occurs because of poor lubrication of the moving parts. This may be caused by uneven expansion as the engine warms up from cold making some running clearances tight and cold oil is more difficult to pump round the engine. This is why, as far as I know, all modern high powered engines have pre-heaters - to reduce initial uneven expansion, improve initial combustion conditions and make sure the oil reaches the parts it should. A survey of the literature shows that a temperature of around 40 deg C is sufficient to enable a satisfactory engine life to be obtained.

Your concerns are, I maintain, misplaced.

 

[DidcotDickie]

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.

SNIP
Your concerns are, I maintain, misplaced.

Spot on Coppercapped. I was at an IMechE meeting in Swindon a couple of years ago and asked the Network Rail engineer the question. That is exactly the answer we got.

And if you look at the main steelwork that has gone up between Stocks Lane crossing and the loops at Steventon you can clearly see there will be no gap in the OLE under the High St bridge. So there is not reason why, once this is complete, which I suspect it will be shortly, that the Didcot national grid feeder at Foxhall Junction will be able to supply as far as Wootton Bassett Junction and beyond if necessary.

 

[Mag_seven]

There will be no gap at Steventon - this seems to be an urban myth that won't die.

Looks like you've just killed it then It doesn't appear to be common knowledge for whatever reason!

 

[snowball]

Looks like you've just killed it then It doesn't appear to be common knowledge for whatever reason!

Previous statements on this thread didn't kill it, so probably this one won't.

 

[Class 170101]

I had a look from the google link Snowball posted earlier and I expected the bridge to be closer than it looked in the google shot. How far away is the crossing the google car is on to the bridge in question?

 

[snowball]

I had a look from the google link Snowball posted earlier and I expected the bridge to be closer than it looked in the google shot. How far away is the crossing the google car is on to the bridge in question?

Which post of mine are you referring to? In the recent one the google car is not on a crossing, nor looking at a bridge.

 

[Class 170101]

You would have to raise the road from which this view is taken, so the houses on the left would probably be for the chop.

https://www.google.co.uk/maps/@51.6...4!1siFSJeN6-s3buHrhRM_fcAg!2e0!7i13312!8i6656

This one. If you put google car on the crossing there is a bridge in the distance.

 

[snowball]

This one. If you put google car on the crossing there is a bridge in the distance.

From the OS 1:25k map at streetmap.co.uk, the bridge is about 400m from the crossing.

 

[Class 170101]

From the OS 1:25k map at streetmap.co.uk, the bridge is about 400m from the crossing.

Must admit I thought the way it was being spoken about that it was much closer than that.

 

[mr_jrt]

Judging by the amount of crews out each night for every discipline, the only thing that will hold this back will be material shortages, as they've finally got the plan sorted where we're not tripping over each other, i.e main steel gets done, then sps follow then ATF and earth, then contact and catenary etc etc. Only taken 3 years to sort but good to see it working in practice at last

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

 

[Class 170101]

Would it not be possible to have a gap over the level crossing instead similar to some Dutch lines where they have gaps over short river bridges?

 

[coppercapped]

Why would you want to have a gap?

 

[59CosG95]

Would it not be possible to have a gap over the level crossing instead similar to some Dutch lines where they have gaps over short river bridges?

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.

 

[edwin_m]

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.

 

[deltic08]

Have you actually looked at a Cotswold Line timetable? A limited number of services skip a limited number of stops (I am not counting the Oxfordshire halts) but that's it. Most, the Cathedrals Express included, make seven intermediate calls between Oxford and Worcester in the space of 60 miles. West of Worcester there are also short intervals between stops, combined with some stiff climbs in the Malvern hills.

That is a punishing cycle of work for any diesel engine, be it above the floor in an HST, or under it in an 800. If the engines can cope with that kind of treatment, I fail to see why going to Bedwyn suddenly takes them into some zone where they will fall to bits. Perhaps the people at Rolls Royce-MTU who build the engines might have said something about the idea of doing Newbury-Bedwyn and back, interspersed with lots of electric running, if they were worried it would destroy them?

800s were planned from the off for use on a number of Berks & Hants line semi-fast services, which in the peaks are a key part of the commuter services provided by GWR - such as the current HSTs from Westbury and Frome which provide the 06.29 and 06.45 services from Bedwyn to London and the 17.07 and 18.07 from Paddington to Frome and the 18.33 to Exeter.

And if "this cock-up could only happen in the UK" - what a tired old cliche that is - why on earth has SNCF bought several hundred bi-mode and bi-mode, bi-current trains for use in France in recent years? Why did the Spanish modify Talgo high-speed electric units with diesel generator cars so they can work beyond with wires? Must be some cock-ups on the Continent too.

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.

 

[furnessvale]

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.

There is no technical reason why electrification over a swing bridge needs to be discontinuous.

 

[ArchieWoodbine]

If we're really getting into the realms of fantasy - one solution might be to install a ROCS (rigid overhead conductor system) accross the level crossings at Steventon, and then have this swing up and out of place when not in use. A simmilar solution is used (although very infrequently) on the Trowse swing-bridge in Norwich.

But, as others have said, the chosen and best option is to run the wire and have a temporary speed restriction until a time when the bridge can be raised and/or the level crossings closed.

Whilst we're discussing power-supply options, I think it's worth clarifying that the supply at Thingley is reached by a seperate cable, which will feed into Christian Malford ATS (you can see this from the train already in the down cess). So full completion of the OLE from Thingly to Christian Malford isn't strictly required to energise Wootton Bassett Jnc. - Parkway.

 

[themiller]

The Swiss do not have any bimodes.

What about SBB Eem923, BLS class 187, and SRT class 187? I know that the 187s have last mile engines and they must work hard when starting a heavy freight away from the wires. The Eem 923 is a shunter which can be stopping and starting its 360kW diesel several times in a shift to get heavy consists out of non-electrified lines.

 

[doa46231]

And if "this cock-up could only happen in the UK" - what a tired old cliche that is - why on earth has SNCF bought several hundred bi-mode and bi-mode, bi-current trains for use in France in recent years? Why did the Spanish modify Talgo high-speed electric units with diesel generator cars so they can work beyond with wires? Must be some cock-ups on the Continent too.

Perhaps the reason is the French system at more than 29000 miles is far bigger than ours.
They need far more trains than we do. It's a much bigger Country altogether which makes our inability even to fully electrify a short flat, straight main line even more reprehensible

The vast majority of their lines are electrified as a look at the electrification maps of France will show.
They are, incidentally still electrifying those routes not yet done.
It is spurious to imply the French are doing the same as us as regards bimodes.
They are using them to travel to the extremities as is sensible, whereas we are ordering them as a bailout for being unable to electrify our lines at an economic price.
And as for trying to stick diesels under old electric trains, well the mind boggles.

 

[59CosG95]

There is no technical reason why electrification over a swing bridge needs to be discontinuous.

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.

 

[dp21]

And if "this cock-up could only happen in the UK" - what a tired old cliche that is - why on earth has SNCF bought several hundred bi-mode and bi-mode, bi-current trains for use in France in recent years? Why did the Spanish modify Talgo high-speed electric units with diesel generator cars so they can work beyond with wires? Must be some cock-ups on the Continent too.

Let's not forget when SNCF bought a fleet of trains which didn't fit

 

[jimm]

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.

If you are so worried about MTU's delicate flowers of engines, I suggest you write to Mr Grayling at the DfT, telling him what fools he, Hitachi and GWR all are, and demand that the electrification teams are ordered onwards to Bedwyn (why not Penzance while we're at it?) forthwith.

Please stop going on about what supposedly happened some tine, somewhere else in Europe - or at least do some research first. To take but two examples from France, SNCF only got finished with electrifying the line from Paris to Cherbourg (not exactly a backwater branch) in 1996. They never electrified the old main line to Strasbourg and adjacent areas in eastern France - the loco-hauled diesel services were simply superceded by the two phases of LGV East in recent years, not the 1960s.

If you think French bi-modes are for branch lines, I refer you to the Coradia Liner, purpose-built for long-distance services, including the non-electrified sections of the routes east of Paris that still need diesel traction - 55 either built or on order so far, plus nine electric-only sets based on the same platform.

Perhaps the reason is the French system at more than 29000 miles is far bigger than ours.
They need far more trains than we do. It's a much bigger Country altogether which makes our inability even to fully electrify a short flat, straight main line even more reprehensible

The vast majority of their lines are electrified as a look at the electrification maps of France will show.
They are, incidentally still electrifying those routes not yet done.
It is spurious to imply the French are doing the same as us as regards bimodes.
They are using them to travel to the extremities as is sensible, whereas we are ordering them as a bailout for being unable to electrify our lines at an economic price.
And as for trying to stick diesels under old electric trains, well the mind boggles.

Ordering lots of bi-modes, and over a long time period now, including more last year, doesn't exactly suggest that SNCF is rushing around with wiring trains here there and everywhere, does it?

You can go into the ins and outs of the politics of electrification in this country for 50 years all you like - it is indeed a pretty sorry saga - but even if the initial GW electrification plan had all gone swimmingly, there are an awful lot of places with regular services to London on the GWR network that were not included in that plan and would be a long way behind schemes like Midland Main Line, TransPennine, XC, etc, etc in the list of priorities for further electrification

So if we weren't going to order bi-modes to cover services for the non-wired bits of the GWR network, what else do you suggest they should have done to serve the Cotswolds, Gloucestershire and the West Country while we wait for electrification? Perhaps we should keep the HSTs going so long they would be entitled to a free bus pass and an old age pension?