Devon & Filton banks - could electrification on uphill sections be possible?

[MatthewRead]

Electrification is more to do with the sheer number of people that are carried on the trains in London and the South East, rather than who is carried on them.

Assuming that electrification was only there for bankers then with 145,000 staff in London (assuming working 220 days a year) that's 64 million passenger journeys a year.

Assuming that they all come in on SWR services into Waterloo then they would take up about 2/3's of the number of people who did so (mostly allowing for the WofE services, which wouldn't be carrying any bankers!). However ALL the other stations in London which are electrified would then would not need to be. That also assumes that none of those bankers live within London.

64 million is tiny compared to the nearly 1 billion (heavy) rail journeys that are made in London and the South East. Even if every one of those bank Industry staff in London made a further return journeys a day (not including Intercity travel) to get above 10% of all (heavy) rail journeys in London and the South East. Even then there would be about 9 other people who were not bankers for every banker on every train.

Even if you meant the wider professional and financial services sector London has circa 700,000, which is less than three times the number in Manchester (240,000) yet with a urban population of something like five times as many as Manchester. Therefore, chances are that Manchester has a higher level of bankers per million people than London. However, definitely has a higher level of people working in finance per million people in London.

(Yes I got that your post wasn't serious, but there are some on here who would think that such retoric was sound and that other regions need to have more investment but are missing out due to the bankers on London getting it all for their trains. Whilst the reason that other regions aren't getting the same, perceived, investment is more to do with less people per million using rail. Of course, that could be due to not having the investment in the past and isn't a reason not to invest in rail in other regions. Which is why I think that there should be more investment in rail than there had been. However even so it is unlikely to look like the same sorts of level, just because there's still a fair amount of train lengthening that can be done fairly easily elsewhere -
even if trains only make it to 8 coaches long - whilst London has a significant number of services which are at the maximum 10-12 coaches long during the peaks).

P.S. personally I would love to see the Devon Banks electrified, but feel that chances are it will be done off the back of the local services justifying it (Devon Metro and all that) with the longer distance services being an added bonus. However, I would also like to see a significant percentage of the rail network being electrified and I'm fairly disappointed that more electrification appears to be off the table for the time being.

If for no other reason than so other reasons than so other reasons could have more of London's cast offs, as there's not enough of a market for all their second hand EMU's yet and with the reduction of DUM's that can be cascaded from London (what with the electrification of the GWML) as otherwise that's going to become more of a problem going forward.

P.P.S. for those that missed it; that last paragraph may have been slightly tongue in cheek.

P.P.P.S. maybe not so slightly and less of the maybe

But that's what I want a new home fro all of my favorite EMU's as i go to Devon for holidays every August. The Green Party wanted to see electrification in the South West if only they had more seats and more power:-x

 

[coppercapped]

I'm confused by this. I've always been lead to believe that the journey-time benefit of electrification usually (for non-high-speed lines) comes from better acceleration, not higher top speeds.

I'm not familiar with the line in question, so maybe I've got it wrong - but as I understand it from this thread, the line is very curvy. Doesn't that imply that there would be lots of places where trains need to slow down and then speed up again, which would therefore make it exactly the kind of route where electrification would give time savings (from the better acceleration)?

The line is very curvy and the effect is that overall the line limits are low. I have already posted the speeds in my post No. 59 in this thread, but to save having to scroll back I'll repeat them;

In the Down direction the line limits from Teignmouth are 60/80/90 then 60mph through Newton Abbot. Shortly past Newton Abbot it drops to 55mph and stays at that value to Totnes. Through Totnes the limit is 60mph which stays until Hemerdon where it increases to 80 as far as Tavistock Junction at which point it drops to 60mph. There is a short burst to 70mph past Laira and then a crawl into North Road.

The Up road is similar.

The issue is that it is essentially a 60mph railway from Dawlish to Hemerdon Summit, a distance of over 30 miles of the roughly 50 miles between Exeter and Plymouth. The changes in permitted speed over this section are not great so greater acceleration will not gain much time. The journey from Exeter to Plymouth takes, roundly, an hour depending on the stopping pattern. This time is uncompetitive with the roads and needs to be reduced by considerably more than the few minutes possible by electrification and more power. The only way to do it is to straighten out the curves.

 

[MarkyT]

The line is very curvy and the effect is that overall the line limits are low. I have already posted the speeds in my post No. 59 in this thread, but to save having to scroll back I'll repeat them;


The issue is that it is essentially a 60mph railway from Dawlish to Hemerdon Summit, a distance of over 30 miles of the roughly 50 miles between Exeter and Plymouth. The changes in permitted speed over this section are not great so greater acceleration will not gain much time. The journey from Exeter to Plymouth takes, roundly, an hour depending on the stopping pattern. This time is uncompetitive with the roads and needs to be reduced by considerably more than the few minutes possible by electrification and more power. The only way to do it is to straighten out the curves.

And to build a new cutoff line from Exeter to Newton Abbot for expresses to save up to about 5 miles on the journey which today is rather curvy along the estuaries and sea wall sections and thus also limited in speed, as well as being a long way round.

 

[YorkshireBear]

Mr Grayling has just re-iterated that there are better solutions than electrification. He should know - he has a 2:1 BA in History and demonstrable lack of understanding of the word "truth".

Incredibly for someone with a degree in history he seems absolutely oblivious the the fact that history is repeating itself.

 

[jimm]

The journey from Exeter to Plymouth takes, roundly, an hour depending on the stopping pattern. This time is uncompetitive with the roads and needs to be reduced by considerably more than the few minutes possible by electrification and more power. The only way to do it is to straighten out the curves.

Not this old myth again.

The AA website gives a typical driving time between Exeter and Plymouth of 54 minutes. In what way is a typical rail journey around the hour mark uncompetitive with that?

Yes, on a quiet day on the roads you can get there in less than 54 minutes, but there are plenty of times when it isn't quiet, or there is congestion at either end, even if the A38 is okay in between.

Where rail does lose out badly time-wise is journeys on into Cornwall, where driving on the A30 via Okehampton wins hands down most of the year.

I'm not sure anyone views electrification of the Devon banks as some sort of transformative elixir for running times, should it ever happen - it's more the sustained improvement in performance that electric offers over diesel on those sort of gradients.

 

[coppercapped]

Not this old myth again.

The AA website gives a typical driving time between Exeter and Plymouth of 54 minutes. In what way is a typical rail journey around the hour mark uncompetitive with that?

Yes, on a quiet day on the roads you can get there in less than 54 minutes, but there are plenty of times when it isn't quiet, or there is congestion at either end, even if the A38 is okay in between.

Where rail does lose out badly time-wise is journeys on into Cornwall, where driving on the A30 via Okehampton wins hands down most of the year.

I'm not sure anyone views electrification of the Devon banks as some sort of transformative elixir for running times, should it ever happen - it's more the sustained improvement in performance that electric offers over diesel on those sort of gradients.

You are, of course, correct! In my mind was the time to Cornwall by rail compared to the A30. By road from Exeter to Plymouth is still 45 or 50 miles, depending where one starts and where one stops, and to do that in an hour requires some low flying along the A38!

But a higher speed and a less curvy route is still needed to improve the competitive position of the railways, both to Plymouth and to points further west. The priorities have to be (a) less curvy with a higher line speed and then (b) more power, possibly by electrification.

 

[Taunton]

The AA website gives a typical driving time between Exeter and Plymouth of 54 minutes. In what way is a typical rail journey around the hour mark uncompetitive with that?

Because neither St Davids nor North Road, particularly the latter, are really in the middle of things, not convenient for the commercial or retail areas of either city. Typical GWR unfortunately. So whereas the car takes you between your start and end points, the train doesn't.

 

[HowardGWR]

Because neither St Davids nor North Road, particularly the latter, are really in the middle of things, not convenient for the commercial or retail areas of either city. Typical GWR unfortunately. So whereas the car takes you between your start and end points, the train doesn't.

As the original GWR station was Millbay, to which local trains were directed, that (in my emboldening) seems perhaps somewhat off the mark. If we also note that the LSWR station was at Friary, both stations were reasonably convenient for city centre visitors from local surrounding areas. Blame, rather, the 60s retrenchment. On the wider point, I don't see that it matters too much about North Road. Plenty of buses go past it and the same in Exeter, where an arriving passenger just might also get a convenient lift up the hill on a 14x or 15x.

I always think the supposed centre to centre traffic between two nearby cities could be exaggerated. Who wants to go from Marks and Spencer Exeter to the same shop in Plymouth?

Update: Surely the real point is the contribution to shorter journeys from and to further afield?

 

[muddythefish]

This time is uncompetitive with the roads and needs to be reduced by considerably more than the few minutes possible by electrification and more power. The only way to do it is to straighten out the curves.

A clear case for building a high-speed line (HS4 5 or 6?) over Dartmoor.

 

[HowardGWR]

A clear case for building a high-speed line (HS4 5 or 6?) over Dartmoor.

Since that cannot be done (National Park) I assume you are TIC.

 

[Cowley]

A clear case for building a high-speed line (HS4 5 or 6?) over Dartmoor.

Dartmoor National Park will barely let you put a shed up, let alone build a new railway!

 

[JohnElliott]

Dartmoor National Park will barely let you put a shed up, let alone build a new railway!

Under Dartmoor, then.

 

[Class 170101]

Well apparently John McDonnell has suggested that the GWML should be electrified to Penzance at the Labour Conference today

 

[GRALISTAIR]

Well apparently John McDonnell has suggested that the GWML should be electrified to Penzance at the Labour Conference today

I don't want to start a political thing - but do you get the feeling that electrification will not go away no matter what Grayling says( full disclosure I am a lifelong Conservative voter)?

Scotland is doing it regardless, Labour want it (OK maybe to make political capital), Lib Dems and Greens want it. Diesel burning use of fuel will be on decline - particulates, Middle East etc environment etc.

I think Grayling is on the wrong side of history - no matter how much has been done in the last 8 years. My 2 cents

 

[edwin_m]

Because neither St Davids nor North Road, particularly the latter, are really in the middle of things, not convenient for the commercial or retail areas of either city. Typical GWR unfortunately. So whereas the car takes you between your start and end points, the train doesn't.

I think the confusion here arises from the rail replacement buses starting at Tiverton during Dawlish washout etc being quicker than the train from there to Plymouth. No doubt if your journey starts near St Davids and ends near North Road the train would be quicker, because even though neither station is particularly central it is close enough in for congestion delays when trying to get there by road. But it probably means that road is quicker for most journeys that start in the Exeter area and end in the Plymouth area or vice versa.

I presume when climbing the Devon Banks the trains run at moreorless the permitted speeds, so journey time is limited by curvature not by train performance. If so then a straighter alignment would save more time than electrification even if it had similar gradients to the existing, because the trains could then run faster downhill. However a straighter alignment would cost several times as much as electrification would.

 

[Busaholic]

You are, of course, correct! In my mind was the time to Cornwall by rail compared to the A30. By road from Exeter to Plymouth is still 45 or 50 miles, depending where one starts and where one stops, and to do that in an hour requires some low flying along the A38!

But a higher speed and a less curvy route is still needed to improve the competitive position of the railways, both to Plymouth and to points further west. The priorities have to be (a) less curvy with a higher line speed and then (b) more power, possibly by electrification.

Penzance to Exeter by car = allow 2 hours.
Penzance to Exeter by rail = allow 3 hours.

In both cases it can be done in a little under those times, but there's still basically an hour difference between modes. With the new bi-modes we are promised a ten minute speed-up (at most) between Penzance and Paddington, which is not exactly going to get the heart racing!

 

[HowardGWR]

Penzance to Exeter by car = allow 2 hours.
Penzance to Exeter by rail = allow 3 hours.

In both cases it can be done in a little under those times, but there's still basically an hour difference between modes. With the new bi-modes we are promised a ten minute speed-up (at most) between Penzance and Paddington, which is not exactly going to get the heart racing!

I think the problem in Cornwall is that there is no very large town /city in it, especially at the far end. To justify electrification, one usually has to have large populations. Even now, they are just getting around to some of the electrification in the north west, between Liverpool and Manchester.

It's not the speeds that are most important, it's the fact that it isn't mass transit.

 

[Busaholic]

I think the problem in Cornwall is that there is no very large town /city in it, especially at the far end. To justify electrification, one usually has to have large populations. Even now, they are just getting around to some of the electrification in the north west, between Liverpool and Manchester.

It's not the speeds that are most important, it's the fact that it isn't mass transit.

I've got causes far dearer to my heart than electrifying the Cornish main line.

 

[MarlowDonkey]

The priorities have to be (a) less curvy with a higher line speed and then (b) more power, possibly by electrification.

The French TGV lesson is that gradients don't that matter, but you do have to build in a straight line.

 

[coppercapped]

I don't want to start a political thing - but do you get the feeling that electrification will not go away no matter what Grayling says( full disclosure I am a lifelong Conservative voter)?

Scotland is doing it regardless, Labour want it (OK maybe to make political capital), Lib Dems and Greens want it. Diesel burning use of fuel will be on decline - particulates, Middle East etc environment etc.

I think Grayling is on the wrong side of history - no matter how much has been done in the last 8 years. My 2 cents

I am not trying to defend Grayling, but I would point out that he is trying to make the best political narrative he can out of what is a disastrous situation. For a multitude of reasons Network Rail has not completed any of the electrification projects it was asked to do on schedule or on budget. The delay on the GW is some three years and costs have more than doubled. Other enhancement works are also overspent and delayed so the Control Period 5 settlement of some £38 billion (IIRC) will be spent and much of the work will be uncompleted at the end of the five years.

Until NR can show that it can plan, cost and complete projects on time and to budget any electrification projects are off the agenda.

This is not to say that there are some lines which would benefit from electrification but simply electrifying lines because 'electricity is good' - the religious approach to electrification - is not acceptable. Money should not be spent on electrifying lines simply because a political party wants to do so - it's easy for them to say, but it's not their money that will be spent. There should be good commercial, economic and operational reasons for such expenditure.

The arguments against diesel power for railways are, at best, moot. For speeds up to 125 mile/h modern diesels can supply sufficient power without introducing yet another point of failure into the railway. Future diesels will have to meet tighter emission limits, whether Britain remains in the EU or not. Particulates have become an issue largely because it has become easier to measure them; the answer is not to abandon diesel power but to cause the specifications to be changed to reduce or eliminate as far as possible their emission. Do not judge the performance of modern diesels on that of current power plants on the railway most of which were built long before any emissions limits were applied.

The 'green' aspects of electrification are also over-egged. The quantities of steel, concrete and copper which have to be manufactured and installed are considerable. Diesel power requires none of this. The overall efficiencies of the two approaches are not that far apart - combined cycle gas turbines are better than diesels even allowing for distribution losses but, roundly, three wind turbines have to be built to ensure that at least one is where the wind is. That's expensive! Security of supply of crude oil is always being raised - but apart from the oil price shock in 1972 when people stopped buying - there has never been a break in supply in spite of all the talk of unstable areas in the Middle East. Even through two world wars... The quantity of diesel fuel used by the railways is a fraction of the nation's total consumption - for many years to come there will be enough readily available to power the railways.

For high speed railways which require a lot of power, electricity is the only sensible option. For all other applications (probably mostly suburban and metro-type uses where frequent starts and stops are called for and regeneration is most useful and effective) the maths have to be carefully done. And until NR gets the price of the kit and its installation down no further extensions will be approved by Government if it is footing the bill.

 

[jimm]

I don't want to start a political thing - but do you get the feeling that electrification will not go away no matter what Grayling says( full disclosure I am a lifelong Conservative voter)?

Scotland is doing it regardless, Labour want it (OK maybe to make political capital), Lib Dems and Greens want it. Diesel burning use of fuel will be on decline - particulates, Middle East etc environment etc.

I think Grayling is on the wrong side of history - no matter how much has been done in the last 8 years. My 2 cents

Until the electrification pronouncement, Grayling's only other towering contribution to modern Britain was a ban on books being sent to prisoners in 2014... overturning this ban was pretty much the first thing Michael Gove did when he replaced Grayling as Justice Secretary in 2015.

And Grayling is very much identified as an ally of Theresa May, so any change of Tory leader/PM could well see him on the move/out of office at a rate of knots.

I expect there will be sustained pressure from the industry in the negotiations on Control Period 6 for electrification to Bath and Bristol and Didcot to Oxford, plus the complete core TransPennine scheme, to be made top priorities - electrification is not going to go away.

Midland Main Line may be more of a battle and I can't see Swansea happening unless and until the Welsh Government and DfT can come to some sort of deal on how to pay for Valleys electrification. If wires got to Bridgend/Maesteg, then going on to Swansea becomes more do-able.

In other news, the crude oil price is on the move up again, as Opec's members cut production to try to boost their margins... Grayling probably won't look too clever if it gets back near to $100 a barrel.

 

[DynamicSpirit]

I am not trying to defend Grayling, but I would point out that he is trying to make the best political narrative he can out of what is a disastrous situation. For a multitude of reasons Network Rail has not completed any of the electrification projects it was asked to do on schedule or on budget. The delay on the GW is some three years and costs have more than doubled. Other enhancement works are also overspent and delayed so the Control Period 5 settlement of some £38 billion (IIRC) will be spent and much of the work will be uncompleted at the end of the five years.

Until NR can show that it can plan, cost and complete projects on time and to budget any electrification projects are off the agenda.

To what extent is that NR's fault, and to what extent does it reflect issues on old track that couldn't have been foreseen? And to what extent does it reflect the previous loss of skills because there was no prior history of ongoing electrification to keep skills and a supply chain going? To the extent that the problems have been caused by the latter issues, it would seem sensible to apply a nuanced analysis - for example, that takes into account that when you electrify, you're also getting the track brought up to modern standards as part of that work (while also acknowledging that costs are going to be high).

Future diesels will have to meet tighter emission limits, whether Britain remains in the EU or not. Particulates have become an issue largely because it has become easier to measure them; the answer is not to abandon diesel power but to cause the specifications to be changed to reduce or eliminate as far as possible their emission. Do not judge the performance of modern diesels on that of current power plants on the railway most of which were built long before any emissions limits were applied.

It's not just emissions though. It's also a question of diesels being much noisier, and also less comfortable for passengers because you have the vibrations from very large internal combustion engines. Can modern diesels realistically fix those problems? The noise issue is particularly severe when the train is starting from stopped - which unfortunately is often in exactly the place where you least want it: In stations!

 

[GRALISTAIR]

------, it would seem sensible to apply a nuanced analysis - for example, that takes into account that when you electrify, you're also getting the track brought up to modern standards as part of that work ----

Take bridges also. If you have to rebuild because of electrification then rebuild to modern standards with pavements and strengthening and even widening at the same time - also known as - rebuilding Victorian infrastructure.

 

[coppercapped]

To what extent is that NR's fault, and to what extent does it reflect issues on old track that couldn't have been foreseen? And to what extent does it reflect the previous loss of skills because there was no prior history of ongoing electrification to keep skills and a supply chain going? To the extent that the problems have been caused by the latter issues, it would seem sensible to apply a nuanced analysis - for example, that takes into account that when you electrify, you're also getting the track brought up to modern standards as part of that work (while also acknowledging that costs are going to be high).

While I agree that some problems could not have reasonably been foreseen and the loss of skills is also a possible factor, neither of these things is important at the moment. The issue is - can NR be trusted to get things done in the time and with the money it predicted?

Whatever the causes, the cash will only flow when NR can show it can deliver what it promised.

It's not just emissions though. It's also a question of diesels being much noisier, and also less comfortable for passengers because you have the vibrations from very large internal combustion engines. Can modern diesels realistically fix those problems? The noise issue is particularly severe when the train is starting from stopped - which unfortunately is often in exactly the place where you least want it: In stations!

Modern diesels can be quieter than older ones. The MTUs in the Class 43s are considerably quieter than the Paxmans they replaced. The Class 80X which I saw passing the other week on diesel power was very quiet - although I admit I didn't hear it start. A common trick to reduce noise and vibrations is to increase the number of cylinders for the same power - the individual power pulses are smaller and the rate of the power pulses increases so vibration levels can be lower. The MTUs in the Class 43 are 16 cylinder engines and older ones had eight. The nearly 1000bhp in the Class 80X trains is developed by a Vee-12, the 750bhp under a Voyager comes from only six. Obviously this only helps to an extent - careful design of the engine housings and mountings are also important. Only experience will show whether the noise, vibration and harshness levels achieved are acceptable but generally modern engines are quieter than older ones.

 

[hwl]

Surely is a major benefit of Devon banks electrification would be reduced diesel usage so each 802 could do more trips in-between each refueling leading to more efficient rolling stock use.
i.e. if the diesel use and not toilet tank filling /emptying or other inspections etc is the limitation on needing to go back to the depot

Presumably this is what GWR's analysis suggested as the most effective in terms of journey time and fuel saving benefits.

 

[The Ham]

Modern diesels can be quieter than older ones. The MTUs in the Class 43s are considerably quieter than the Paxmans they replaced. The Class 80X which I saw passing the other week on diesel power was very quiet - although I admit I didn't hear it start. A common trick to reduce noise and vibrations is to increase the number of cylinders for the same power - the individual power pulses are smaller and the rate of the power pulses increases so vibration levels can be lower. The MTUs in the Class 43 are 16 cylinder engines and older ones had eight. The nearly 1000bhp in the Class 80X trains is developed by a Vee-12, the 750bhp under a Voyager comes from only six. Obviously this only helps to an extent - careful design of the engine housings and mountings are also important. Only experience will show whether the noise, vibration and harshness levels achieved are acceptable but generally modern engines are quieter than older ones.

The problem with comparing modern diesels is that one of the "old" diesels that you compare is that in a Voyager which could continue to see service for another 15 to 20 years.

In that timeframe it should be possible, even for allowing for NR to catch up with the outstanding works and to base new schemes on a much more cautious level of work, for there to be a good few schemes built.

IIRC CP5 was supposed to deliver circa 850 miles of electrified lines. If we assume that we can only do 400 miles per control period and allowing CP6 to have zero miles then in the time before Voyagers and other early 2000 diesels are needing to be replaced (circa end of CP8/mid CP9) we could have done another 800 to 1,000 miles (another 8% to 10% of lines electrified).

Of course as time goes on the routes that are left to be electrified become either easier to do (i.e. the main junctions are done so it's just wiring up the lines in between and/or the number of tracks is reduced, as more lines are 1 or 2 tracks rather than 2 or 4) or harder to do (i.e. those with lots of tunnels and bridges that need sorting or contain very complex junctions). Which could alter the rate at which electrification can happen.

However, my view would be that electrification in Devon would most likely result in wires for the services centred on Exeter, which would mean that the Devon Banks could be left as it is for quite some time. The reason for this is that it would result in a number of the local services being able to be run by EMU's, or at the very least bimodals with them using their engines on the outer edges (thinking towards Banstable and Exmouth) whilst still benefiting from the wires where the most services run and line speeds are fairly high).

However chances are most electrification in the next 20-25 years will likely be focused around Northern Cities, South East Wales and Bristol/Bath (plus a few infill projects elsewhere) where shorter lengths of electrification will allow most of the busiest metro services to change to being run by EMU's leaving the intercity services to only go over to EMU services over the following 10-20 years as the gaps between the cities are bridged so as to avoid needing more bimodal intercity trains once the current fleets of 80x's (including whatever is used on MML and/or XC and introduced early 2020's) become life expired.

 

[The Ham]

Surely is a major benefit of Devon banks electrification would be reduced diesel usage so each 802 could do more trips in-between each refueling leading to more efficient rolling stock use.
i.e. if the diesel use and not toilet tank filling /emptying or other inspections etc is the limitation on needing to go back to the depot

Presumably this is what GWR's analysis suggested as the most effective in terms of journey time and fuel saving benefits.

Yes, that would be a fairly major benefit, however if you assume a similar number of miles of electrification done between Exeter and Taunton then that would mean that more GWR trains would benefit from the use of electric traction and would probably save them more fuel even though the fleets use less fuel per train over that section due to the lack of gradients.

 

[MarkyT]

However chances are most electrification in the next 20-25 years will likely be focused around Northern Cities, South East Wales and Bristol/Bath (plus a few infill projects elsewhere) where shorter lengths of electrification will allow most of the busiest metro services to change to being run by EMU's leaving the intercity services to only go over to EMU services over the following 10-20 years as the gaps between the cities are bridged so as to avoid needing more bimodal intercity trains once the current fleets of 80x's (including whatever is used on MML and/or XC and introduced early 2020's) become life expired.

The beauty of modern bi-modes is that the diesel generator modules are removable easily, at which point the units could become electric only overnight. This decouples electrification projects from the rolling stock and if a more cost effective electrification project materialises it can proceed when ready rather than having to wait for the next round of rolling stock procurement. Significant numbers of bimodes could then be converted into electrics at an immediate saving in diesel servicing, and removing refuelling constraints. Although headlines claim that the whole GWR Hitachi fleet is to be bimode, a fair number of them, even with current limited electrification commitment could run around on all electric diagrams where the diesels never need to start up, once the wires reach Cardiff. Addition of Chippenham - Bristol and Filton bank to the electrified network would allow even more trains to run in electric mode all day, so it begs the question whether some will actually have diesels fitted to them at all times, or whether it would it make more sense for the maintainer to service and store their generator modules in the depot sometimes while certain sets are out all day on all electric diagrams, substituting ballast weights in the engine bay perhaps to maintain expected power/weight ratio. If Hitachi are doing the stock diagramming to meet a train service spec they could arrange this sort of thing and they might be persuaded to help fund more electrification if they can make further savings on the expense of diesel maintenance and the constraints and extra time involved in scheduling fuel stops.

 

[edwin_m]

I am not trying to defend Grayling, but I would point out that he is trying to make the best political narrative he can out of what is a disastrous situation.

And failing utterly on the politics side too - he could have announced a deferment until costs were under control instead of cancelling them entirely. Many people would have seen that as reasonable and it would not have got the backs of several regions up so much.

I'm pretty sure the environmental benefits of electrification in service far outweigh the extra materials used. Lighter trains and regeneration mean that energy use is far less, and the energy can be of any form including nuclear and renewable rather than having to be diesel fuel which pollutes as the point of use.

The beauty of modern bi-modes is that the diesel generator modules are removable easily, at which point the units could become electric only overnight.

Yes you could do that but you'd end up with a much more expensive and heavier unit, with various other design compromises, compared to buying a suitable electric train in the first place. It's a fairly fine balance.

Although headlines claim that the whole GWR Hitachi fleet is to be bimode, a fair number of them, even with current limited electrification commitment could run around on all electric diagrams where the diesels never need to start up, once the wires reach Cardiff.

However most of the Cardiff diagrams start/end their day in Swansea even if they don't visit during the day. Diagrams and depot allocations would have to be re-jigged so some of them went to Filton instead, which would increase costs and also worsen Swansea's services at peak times.

Addition of Chippenham - Bristol and Filton bank to the electrified network would allow even more trains to run in electric mode all day

I think Temple Meads is the big problem here, needing a major remodelling and re-signalling which nobody seems to have even thought about very much yet. Until this is done there is little point in electrifying either route, except perhaps for an incremental extension to Bath. I would even hazard a guess that this makes the Bristol routes are more difficult than Cardiff-Swansea.

 

[MarkyT]

Yes you could do that but you'd end up with a much more expensive and heavier unit, with various other design compromises, compared to buying a suitable electric train in the first place. It's a fairly fine balance.

I know but a substantial proportion of the GWML Hitachi fleet being delivered was originally intended to be electric only so removing the engines should be feasible if that is desirable in the future. I can see problems with weight distribution, perhaps the non electric ones needing a ballast weight instead of an engine, or was the suspension setup going to be tweaked on the originally planned electric sets to cope with a lighter vehicle.

However most of the Cardiff diagrams start/end their day in Swansea even if they don't visit during the day. Diagrams and depot allocations would have to be re-jigged so some of them went to Filton instead, which would increase costs and also worsen Swansea's services at peak times.

Strengthening the case for Swansea electrification then.

I think Temple Meads is the big problem here, needing a major remodelling and re-signalling which nobody seems to have even thought about very much yet. Until this is done there is little point in electrifying either route, except perhaps for an incremental extension to Bath. I would even hazard a guess that this makes the Bristol routes are more difficult than Cardiff-Swansea.

There's an approved scheme for Temple Meads and data testing is underway. No idea of dates for spades in the ground though. The whole resignalling programme was rejigged to prioritise the South Wales line.