IEP for beginners

[Dave1987]

In the words of Wikipedia: [[citation needed]]

I don't believe you that they will be "far more" expensive than comparable electric traction.

I will absolutely grant you that they will in fact be more expensive. But I do not believe it will be "far more"

I think the only way of solving this argument would be if a report detailing the cost per km of a bi-mode was put against the cost per km of having full electric and loco hauling. I think it would be more expensive with bi-mode but I have no way of proving it unfortunately. I think the fact the loco could have use after the wires are fully up but there doesn't seem to be a viable use of the underfloor engine once the wires are completely up.

 

[HSTEd]

Well I would assume each bi-mode set would retain one engine to bring them into line with the electric trainsets.
This would make them self recovering.

Then there is a question about what to do with a bunch of... 900kW? engines.
I would assume there will be some need for relatively light locomotives for operating things like RHTT at some point once the CLass 20s and 31s finally give up the ghost.

Could always put them to use for that.

 

[AndyLandy]

I think the only way of solving this argument would be if a report detailing the cost per km of a bi-mode was put against the cost per km of having full electric and loco hauling. I think it would be more expensive with bi-mode but I have no way of proving it unfortunately. I think the fact the loco could have use after the wires are fully up but there doesn't seem to be a viable use of the underfloor engine once the wires are completely up.

You're right there. Although, I do wonder if there are enough numbers out there to make an educated guess. EMU drags we should be able to establish from a 57+390 formation.

Estimating the running costs of a bi-mode under the wires, the best bet is to work out how much energy is required to shift a 10-car Voyager set.

I wonder if these figures exist and what values they are.

 

[tbtc]

I think the fact the loco could have use after the wires are fully up but there doesn't seem to be a viable use of the underfloor engine once the wires are completely up

When will the wires be up completely? And what about Cross Country? And on diversionary routes?

I don't know where these light engine moves to and from depots have come from. You don't need to send DMU's to the depot each night

These diesel locos (required to haul the electric stock) are going to have a few movements, they'll need stabling somewhere (not necessarily the station that the switchovers will happen)...

Plus what happens to the London - Hereford service if the "68" fails at Oxford? The train gets terminated there? Or do you have a second "68" there just in case?

 

[sprinterguy]

I'd like to see some actual, citable facts about just how catastrophic this "dead weight" will be. A pantograph and transformer can't way more than a couple of tons at the very most, so IEP isn't going to weigh a great deal more than a comparable Voyager or HST set. That, at least suggests that IEP bi-modes should come in cheaper per-mile than existing diesel traction.

Supporting your stance, a 5-car Class 221 DEMU weighs 283.2 tonnes (280.7 tonnes with the tilt equipment removed). A 5-car Class 390 EMU, if such a thing existed, would weigh around 260 tonnes.

Based on the most recently published weights for the IEP trains, which were released after the change from power cars to underfloor engines had occurred, a 5-car Bi-mode IEP will weigh 249 tonnes. This means that the two additional diesel engines and associated equipment must add 16 tonnes to the total train weight, as the 5-car electric IEP trains will weigh 233 tonnes.

The 9-car electric sets can be expected to weigh near enough 400t. I do not have precise figures for the weight of a 9-car set as the published figures state values for the 10-car electric formation that was proposed at the time, which weighs in at 438t. At any rate, as you can see even the Bi-mode IEPs are expected to weigh less than their diesel or electric competitors. This is quite notable when you consider that a 5-car IEP train will actually be closer in total length to a 6-car train formed with 23 metre vehicles, such as a Voyager.

 

[RAGNARØKR]

MPs are meant to represent people living in their constituencies. Clearly you don't live in a UK constituency, so I think I have every right to question why my money, as a UK taxpayer, is being spent answering questions from people who don't live in the UK. Especially when that money is being spent on a desperate attempt to prove your assertion on this forum that the introduction of IEP will require "a major infrastructure upgrade", despite your continued failure to provide any evidence of any such thing being announced by Network Rail, the very company that would be responsible for carrying out any such "major infrastructure upgrade" - something that really shouldn't require the involvement of an MP to uncover, if it were ever going to happen. I couldn't see any sign of your "major infrastructure upgrade" due to the dimensions of IEP coaches in Network Rail's western route business plan the other day either - surely the very place such a thing would be explained. All manner of other major infrastructure upgrades are mentioned, but not one to do with the length of IEP coaches. How odd.

The Lawn at Paddington is a confined area, with only some of the platform ends adjacent to it anyway. The alterations made at Paddington created a large circulation area for railway passengers using this railway station. What you suggest would punch an awkward hole into that circulation area. What are you going to call for next in your 'bring back the 1950s' musings? Should Liverpool Street also be turned back to its former state, where there used to be a couple of long platforms that effectively cut the station in two?

It would be lovely to see the Cotswold Line electrified but it just isn't going to happen in the short term. Once XC wires go up past Worcester, also allowing the possibility of electric regional services from Birmingham to Worcester and Hereford in conjunction with a Cotswold scheme, the prospects of it happening will improve. In the meantime, some other solution is required to maintain through services to Paddington for a number of years to come.

It is strange that you, as a British taxpayer, should be concerned at the trivial cost of obtaining information, when you are evidently content to see a project go ahead which, on the basis of the Foster report, is substantially more expensive than the alternatives to the tune of a billion or two. I am a UK taxpayer as well so have a right to know where the money is going, besides which it has to be a matter of public interest. Given the way the Foster report was sidelined, British taxpayers should be angry about the waste of money involved. But if you have had a sight of the figure, why not give it, quoting chapter and verse, then I can write to my MP to say that I have obtained the information, thereby saving the pennies you are so concerned about.

It is inconceivable that substantially longer vehicles than those presently running could not be introduced without costly changes to improve the clearances, otherwise - and this stands to reason - longer vehicles would have been introduced long ago. Now it will of course be the case that some improvements will have been made in the course of other work, at marginal cost, but from comments made on other threads the route availability of the stock will be less than ideal due to the increased length.

But if there is a need to maintain a service of full length trains to Worcester, then the obvious and simple solution is to push/pull them with a loco change at Oxford or wherever the wires run to.

 

[sprinterguy]

Then there is a question about what to do with a bunch of... 900kW? engines.

700kW, or 940hp.

 

[RAGNARØKR]

Plus what happens to the London - Hereford service if the "68" fails at Oxford? The train gets terminated there? Or do you have a second "68" there just in case?

How often is that likely to happen? The same as what happens if anything on the train fails which means it has to be taken out of service. Unless there is a spare loco but why it have to be a class 68? Presumably there will be some DMUs around still for the local services.
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Regular drags doesn't seem to have worked since the days of 33s on the Southern region.

That doesn't tend to stop some people from having opinions though, does it?

The class 33/TC/REP operation was slick. If you can read a drawing you will have a good idea of what something is going to be like.

 

[tbtc]

I do wonder if there are enough numbers out there to make an educated guess

Okay, I'm up for that. Based on current service frequencies, and assuming that all CP5 electrification gets done then we'll need

• One 68 for Harrogate - Leeds
• One 68 for Inverness - Edinburgh
• Two or three 68s for Aberdeen - Edinburgh
• One 68 for Selby - Hull
• One 68 for Swansea - Carmarthen
• Two 68s for Swindon - Cheltenham
• Four 68s for Oxford - Worcester/ Hereford

So you're talking at least a dozen locos required plus spares, plus presumably the scope for extra services (e.g. Bristol -Weston-super-Mare).

The GWML is going to need 21x9 + 36x5 coach trains, so 369 coaches. Add in an extra 227 for the ECML (10x5 + 13x9 - all figures taken from Wiki). So that's roughly 600 coaches (plus potentially more for a follow on order).

So that might mean 650 "conventional" coaches (given the extra three metres of seating on an IEP coach)...

...but then one advantage of IEP is that the five coach portions can be used on the quieter section of line away from London. Using something like a 225 of 390 would mean having to use the full nine/eleven coach train all the way to Hereford/ Inverness etc, which would mean that more coaches were required. So maybe some more coaches?

(just starting by trying to compare the number of vehicles you'd need to construct - will deal with the traction costs etc later)
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I am a UK taxpayer as well so have a right to know where the money is going, besides which it has to be a matter of public interest

I am a Luxembourg taxpayer every time I buy something from Amazon, but I don't bother their MPs

if you have had a sight of the figure, why not give it, quoting chapter and verse, then I can write to my MP to say that I have obtained the information, thereby saving the pennies you are so concerned about

Maybe you could give me chapter and verse on the "significant infrastructure problems" that IEP will need money spending to solve?

How often is that likely to happen? The same as what happens if anything on the train fails which means it has to be taken out of service. Unless there is a spare loco but why it have to be a class 68? Presumably there will be some DMUs around still for the local services

It happened often enough for Virgin to abandon their 390 drags to Holyhead.

I was mentioning the 68s because this seemed to be the class that the anti-IEP posters thought would be hauling the unspecified electric trains beyond the wires.

We don't tend to have several spare locos and DMUs sitting around spare nowadays - the railways are generally too busy.

The class 33/TC/REP operation was slick. If you can read a drawing you will have a good idea of what something is going to be like

How come this efficient operation that worked like clockwork has never been replicated on any of the numerous lines that lie just beyond the limits of electrification then?

 

[Manchester77]

Oh no, now were onto haul EMUs with locomotives now. We're professing through the topics of an average IEP forum quickly...

 

[D365]

Oh no, now were onto haul EMUs with locomotives now. We're professing through the topics of an average IEP forum quickly...

We've been 'discussing' it for a while

 

[Kali]

A few things:

Paddington: I remember it before they extended the concourse ( when it was much less busy ) and it was somewhat cramped then. I don't really want to imagine what it'd be like now.

Bi-mode vs towing: are the sets getting a traction current bus? could you not supply that from the attached locomotive ( which effectively turns it into a detachable power car ) and thus not be hauling any extra dead weight. Presumably there'll be a need to have *some* compatible traction anyway just to haul failed units away - what happens if say, wires come down/other power failure and the diesel on one unit fails to start? is the backup diesel on another set going to manage to haul a second dead unit away? we no longer have the ability to use any random spare traction ( or indeed, have random spare traction ) as rescue units.

How much cost is training drivers for new traction? presumably lightly-used locomotives will last a long time, probably longer than the IEP units and be reasonably cheap to maintain given that. The same maintenance costs could be ascribed to the diesel gens in bi-modes too, but they are using energy while doing nothing.

 

[AndyLandy]

Oh no, now were onto haul EMUs with locomotives now. We're professing through the topics of an average IEP forum quickly...

Is it time we moved on to discussing IEP for the ECML yet? I'm sure there's ground to cover there, too!

 

[Erniescooper]

A few things:


Bi-mode vs towing: are the sets getting a traction current bus? could you not supply that from the attached locomotive ( which effectively turns it into a detachable power car ) and thus not be hauling any extra dead weight. Presumably there'll be a need to have *some* compatible traction anyway just to haul failed units away - what happens if say, wires come down/other power failure and the diesel on one unit fails to start? is the backup diesel on another set going to manage to haul a second dead unit away? we no longer have the ability to use any random spare traction ( or indeed, have random spare traction ) as rescue units.

When towing the Loco ETS just supplies the Auxiliary Converters which give you your 3 phase supply for battery chargers , compressors and HVAC . SNCF have had an autocouple system fitted to diesel locos which allows them to move TGV sets off the wires for years .
I notice you mention what happens if the stand by generator fails to start on an electric IEP set when 25Kv is lost , the DFT in it's press releases claims having stand by power means it can remove the "heavy" 110v batteries from IEP , does this mean in the event of the stand-by not starting in a power outage that the passengers are left with no emergency lighting or emergency HVAC ventilation?

 

[Kali]

I know present ETS supplies are not sufficient for traction power - I was thinking that if there's a traction power bus in the EMU then there's really no reason you can't feed it from the diesel locomotive either ( other than the practicalities of designing the coupling to be quick to use and an extra transformer somewhere ). New t-bird units are not really going to be multipurpose so you might as well design them as feeder power units.

 

[sprinterguy]

I notice you mention what happens if the stand by generator fails to start on an electric IEP set when 25Kv is lost , the DFT in it's press releases claims having stand by power means it can remove the "heavy" 110v batteries from IEP , does this mean in the event of the stand-by not starting in a power outage that the passengers are left with no emergency lighting or emergency HVAC ventilation?

Given that the emergency diesel engines fitted to the electric sets are expected to be tested and run regularly in moving units around depots, is the possibility of one of the emergency engines not starting at a time of need more probable than a rescue locomotive, potentially situated in a siding many miles away to start with, failing to start, or the batteries turning out to be flat (Or running out of power if a train is stranded for several hours) in an electric only train?
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Presumably there'll be a need to have *some* compatible traction anyway just to haul failed units away - what happens if say, wires come down/other power failure and the diesel on one unit fails to start? is the backup diesel on another set going to manage to haul a second dead unit away? we no longer have the ability to use any random spare traction ( or indeed, have random spare traction ) as rescue units.

It seems quite likely that there would be a Bi-mode train in the vicinity in this worst case scenario and, with 2820hp available, more than that of a class 47, I would envisage that a Bi-mode set would be able to haul a stricken 9-car electric set to safety.

 

[Kali]

I forget if we still need bi-modes for Welsh services ( assuming IEP doesn't end up on electric-only routes ), in which case yes that is fine,although we're debating the existence of bi-mode in the first place. One might argue that strategically positioned haulage which gets used a little more frequently than diesel gen units used for emergencies would be even less likely to fail, of course. Given the energy usage pattern of off-wire/rescue haulage a genset diesel with multiple internal power units would seem to make sense, and the chances of all of those failing is comparable to an entire bi-mode unit failing.

So it boils down to cost of pathing/time coupling and splitting/crew training/unit procurement vs energy cost of hauling unnecessary weight around for the life of the units. Maintenance is an interesting one, a batch of a few different units vs extra maintenance for a larger number of similar units.

 

[rebmcr]

New t-bird units are not really going to be multipurpose so you might as well design them as feeder power units.

Very true.

 

[Erniescooper]

Given that the emergency diesel engines fitted to the electric sets are expected to be tested and run regularly in moving units around depots, is the possibility of one of the emergency engines not starting at a time of need more probable than a rescue locomotive, potentially situated in a siding many miles away to start with, failing to start, or the batteries turning out to be flat (Or running out of power if a train is stranded for several hours) in an electric only train?

I was just wondering really how a system with no 110v batteries would work , would the generator start as soon as you set the train auxiliaries to carry out the control system work your 110v batteries normally would or providing a supply to an auxiliary compressor to raise the pantograph or have Hitachi just reduced the number of batteries .

 

[Dave1987]

There is one more argument against bi-mode. Unlike electric only traction bi-modes would have to be refuelled, thats a lots of tanks to refill. Whereas on a loco fuel tanks are much larger and could last prob a whole week or more without the need to refuel.

The main argument against though and that is the immense cost and innefficiency of bi-mode. But if people are willing to pay for this with higher ticket costs then it will happen.

 

[RAGNARØKR]

I am a Luxembourg taxpayer every time I buy something from Amazon, but I don't bother their MPs

Maybe you could give me chapter and verse on the "significant infrastructure problems" that IEP will need money spending to solve?

How come this efficient operation that worked like clockwork has never been replicated on any of the numerous lines that lie just beyond the limits of electrification then?

1 UK citizens have their voting right in their country of nationality, not their country of residence. You must be filling your home with a hell of a lot of books if you are paying as much as I am to the UK government in tax.

2 If the costs of introducing 26 metre stock were trivial why was this not specified for the generation of trains that came into service around 2000? The WCML was completely rebuilt but it was never upgraded to allow 26 metre vehicles. Furthermore, it is arguable whether longer vehicles are the best way of utilising additional space within the kinematic envelope, given the width restrictions on the UK system.

3 There has been nothing comparable to the Waterloo-Bournemouth-Weymouth arrangement since 1988. Kings Cross - Aberdeen continue with HSTs after electrification because they had been running on the ECML since 1979. The only other route where it would have made sense would have been Waterloo-Exeter if it had been decided to extend the electrification to Salisbury. So the answer to your last question is that the situation has never arisen where such an operation would have been appropriate. Additionally, it had long been accepted that limited diesel operation under the wires can be tolerated on the grounds of its claimed higher thermal efficiency and because it reduces demands on the overhead supply.

 

[jimm]

I don't know where these light engine moves to and from depots have come from. You don't need to send DMU's to the depot each night.

You don't know where light engine moves have come from? Well try my post No 191 on page 13. And if you can't be bothered to go and look at it then I'd better try again, hadn't I?

If you just build lots of electric trains of some sort for the GWML and use locos to drag them beyond the wires, where is most of this dragging actually going to happen? Oxford to Worcester, Great Malvern or Hereford and Swindon to Cheltenham, both routes planned for minimum hourly frequencies with IEP, and double that in the peaks in the direction of the main morning and afternoon flows.

There isn't an FGW traction maintenance depot on either of these sections of line. It's near enough 60 miles from Oxford to Old Oak Common, Swindon to Bristol is 40-plus and those are the places locos would presumably have to go for maintenance, unless you're suggesting they can be looked after in the open in some carriage sidings, miles from any fuelling point, unless they ask nicely to use LM's facilities at Worcester. No, they wouldn't have to go to a depot every night but they will still need to go to a depot on a regular basis to undergo exams, get repairs, etc.

Hope that's clear enough.

Two 68s for Swindon - Cheltenham
Four 68s for Oxford - Worcester/ Hereford

I think you're being rather too generous to the loco fans with these estimates. Just two locos to run what is meant to become an hourly service to Cheltenham? Heroic availability is putting it mildly. Same would apply to just four for Cotswold duties. As I said above, the service isn't all neat and tidy, shuttling up and down between the same places - Hereford is a two-hour run from Oxford and other trains to and from London currently turn round at Moreton-in-Marsh, Worcester and Great Malvern as well. Plus Charlbury if you add in the morning peak London train that now starts there. And if you're going to continue sending empty stock from Bristol to Hereford each morning and back in the evening, that takes locos way off the patch as well.

But if you have had a sight of the figure, why not give it, quoting chapter and verse, then I can write to my MP to say that I have obtained the information, thereby saving the pennies you are so concerned about.

I haven't had sight of anything, because I am still waiting for you - the person who claimed that "a major infrastructure upgrade" will be needed to allow IEP to operate - to produce any evidence for this assertion, never mind what it might cost if such a thing were actually required.

 

[tbtc]

There is one more argument against bi-mode. Unlike electric only traction bi-modes would have to be refuelled, thats a lots of tanks to refill. Whereas on a loco fuel tanks are much larger and could last prob a whole week or more without the need to refuel

We seem to manage to refuel different coaches on DMUs (instead of one locomotive) as standard nowadays, so this would be nothing new.

There may be more tanks to fuel on a bi-mode IEP, but then you could argue that each tank is using less energy than a loco (and that in the event of one engine failure the multiple tanked train could still function).

Swings and roundabouts really, but if a single loco was that much more efficient then I doubt we'd have seen nine coach 222s being built.

The main argument against though and that is the immense cost and innefficiency of bi-mode. But if people are willing to pay for this with higher ticket costs then it will happen.

Again, higher ticket costs. But we don't know how the costs stack up. IEP looks expensive in the way that an "all inclusive" holiday looks expensive. Are you comparing all costs though?

1 UK citizens have their voting right in their country of nationality, not their country of residence. You must be filling your home with a hell of a lot of books if you are paying as much as I am to the UK government in tax

Just taking your "I am a UK taxpayer as well so have a right to know where the money is going" comment at face value. Am sure our MPs have nowt better to do.

2 If the costs of introducing 26 metre stock were trivial why was this not specified for the generation of trains that came into service around 2000? The WCML was completely rebuilt but it was never upgraded to allow 26 metre vehicles

I believe that the 25m end carriages of 390s cope with most of the WCML?

3 There has been nothing comparable to the Waterloo-Bournemouth-Weymouth arrangement since 1988. Kings Cross - Aberdeen continue with HSTs after electrification because they had been running on the ECML since 1979. The only other route where it would have made sense would have been Waterloo-Exeter if it had been decided to extend the electrification to Salisbury. So the answer to your last question is that the situation has never arisen where such an operation would have been appropriate

There are plenty of routes where you could have had EMU-drags, if they worked.

For example, Walsall to Rugeley, Oxted to Uckfield, Springburn to Cumbernauld (as well as extending electrified London trains beyond the wires to Blackpool, Shrewsbury, Lincoln etc).

Nobody seems to have been interested in this apparently reliable technology since the days of Class 33s (apart from the weekly 390 to Holyhead). That suggests that it wasn't quite as good.

 

[Dave1987]

In complying with emmisions regulations on underfloor engines the fuel efficiency drops significantly. Good example class 172's. This is not the case with a loco they can comply with emissions regulations and still have good fuel efficiency. Plus as I said a loco would not have to be refueled as often so could stable at the attachment station.

Whatever valid arguments there are against bi-mode it seems the DFT are insistant on bi-mode trains so looks like you guys will have your wish. Just dont complain if ticket prices go through the roof to pay for it!

 

[HSTEd]

In complying with emmisions regulations on underfloor engines the fuel efficiency drops significantly. Good example class 172's. This is not the case with a loco they can comply with emissions regulations and still have good fuel efficiency. Plus as I said a loco would not have to be refueled as often so could stable at the attachment station.

A multiple units fuel capacity will laugh in the face of the locomotive, which will be lucky to get 5000L or so.

An DMU with similar horsepower could have more fuel than that.

And the "fuel efficiency" stuff that is often quotes about DMUs and loco hauled formations just isn't true in any real sense.
Per hundreds of seat kilometre HSTs don't come off that much better than Class 222s, and this can be ascribed to the vastly greater horsepower a 9-coach 222 (often used as the basis for comparison) has compared to a HST.

A locomotive will need refueling just as regularily as a DMU, despite what locomotive lovers around here like to think.

 

[Dave1987]

A multiple units fuel capacity will laugh in the face of the locomotive, which will be lucky to get 5000L or so.

An DMU with similar horsepower could have more fuel than that.

And the "fuel efficiency" stuff that is often quotes about DMUs and loco hauled formations just isn't true in any real sense.
Per hundreds of seat kilometre HSTs don't come off that much better than Class 222s, and this can be ascribed to the vastly greater horsepower a 9-coach 222 (often used as the basis for comparison) has compared to a HST.

A locomotive will need refueling just as regularily as a DMU, despite what locomotive lovers around here like to think.

That is just totally untrue! How can you use the class 222 that was built 10 years as a comparison to fuel efficiency considering this does not have to comply with new emission regulations! The class 172 does comply with emisssion regs and has very bad fuel efficiency! A loco would be far more efficient on fuel as it is far easier to comply with emmisions regs on them so would need to be refueled less. Also the fuel tank on a loco is huge! Sorry but the anti loco brigade need to face facts too!!

 

[RAGNARØKR]

We seem to manage to refuel different coaches on DMUs (instead of one locomotive) as standard nowadays, so this would be nothing new.

There may be more tanks to fuel on a bi-mode IEP, but then you could argue that each tank is using less energy than a loco (and that in the event of one engine failure the multiple tanked train could still function).

There may be more tanks to fuel on a bi-mode IEP, but then you could argue that each tank is using less energy than a loco (and that in the event of one engine failure the multiple tanked train could still function).

On another thread there was a discussion of the logistics of this process and the waste of fuel that can occur due to spillage.

Swings and roundabouts really, but if a single loco was that much more efficient then I doubt we'd have seen nine coach 222s being built.

The break-even point for locos is generally accepted to be 5/6 cars. There were other reasons for the 9 car 222s.

Again, higher ticket costs. But we don't know how the costs stack up. IEP looks expensive in the way that an "all inclusive" holiday looks expensive. Are you comparing all costs though?

Depends what IEP is compared against. The extravagance of IEP is revealed in the Foster report.

Just taking your "I am a UK taxpayer as well so have a right to know where the money is going" comment at face value. Am sure our MPs have nowt better to do.

These requests are just passed on through the system and since the information is readily available, it will pop up at the click of a mouse. If it exists. If it doesn't, then it ought to.

I believe that the 25m end carriages of 390s cope with most of the WCML?

In which case why were the rest of the 390s not built to that length? Length is actually not the issue, it is spacing between bogies. Go back to that diagram I posted. You cannot buck the facts of geometry.

There are plenty of routes where you could have had EMU-drags, if they worked.

For example, Walsall to Rugeley, Oxted to Uckfield, Springburn to Cumbernauld (as well as extending electrified London trains beyond the wires to Blackpool, Shrewsbury, Lincoln etc).

Why drag from Hurst Green to Uckfield when the whole route to London can perfectly well be run with a DMU? The Aylesbury line on the Met worked nicely for 40 years with loco haulage and a change-over with a four minute allowance, after which the routes were re-arranged.

Nobody seems to have been interested in this apparently reliable technology since the days of Class 33s (apart from the weekly 390 to Holyhead). That suggests that it wasn't quite as good.

It suggests nothing of the kind. It has more to do with the fact that the outer ends of the system were considered unimportant and it was easier to let the relatively small number of through passengers change trains.
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There isn't an FGW traction maintenance depot on either of these sections of line. It's near enough 60 miles from Oxford to Old Oak Common, Swindon to Bristol is 40-plus and those are the places locos would presumably have to go for maintenance, unless you're suggesting they can be looked after in the open in some carriage sidings, miles from any fuelling point, unless they ask nicely to use LM's facilities at Worcester. No, they wouldn't have to go to a depot every night but they will still need to go to a depot on a regular basis to undergo exams, get repairs, etc.

There is a facility at Oxford for refuelling of the present DMUs. You put up a small building to handle the simpler maintenance tasks under cover. That deals with this difficulty. IEPs will also need new maintenance facilities.

I haven't had sight of anything, because I am still waiting for you - the person who claimed that "a major infrastructure upgrade" will be needed to allow IEP to operate - to produce any evidence for this assertion, never mind what it might cost if such a thing were actually required.

OK, I agree, the system has been ready for 26 metre vehicles for the past decade and all those Voyagers and Adelantes could have been made up of 26 metre long vehicles. How does that sound?

 

[The Ham]

That is just totally untrue! How can you use the class 222 that was built 10 years as a comparison to fuel efficiency considering this does not have to comply with new emission regulations!

I think you'll find that they were comparing the fuel efficiency of a 222 with a HST which was also built when it did not have to comply with emission regulations, therefore a fairly fair comparison.

Per hundreds of seat kilometre HSTs don't come off that much better than Class 222s

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If the costs of introducing 26 metre stock were trivial why was this not specified for the generation of trains that came into service around 2000? The WCML was completely rebuilt but it was never upgraded to allow 26 metre vehicles. Furthermore, it is arguable whether longer vehicles are the best way of utilising additional space within the kinematic envelope, given the width restrictions on the UK system.

Firstly, has anyone checked to see if the IEP will not fit up the WCML? (probably not NR as they are not being planned to be used on that line, so I must assume that have you personally checked them). Longer coaches are only a problem of bends with a radius of tighter than 200m (I think that is the figure you keep quoting), therefore unless you know of bends where this is the case then it is likely that the only reason that IEP will not be cleared for the WCML is because it has not been checked.

Secondly If the GWML & ECML where to have had new trains in 2000 they would have not had 26m long coaches either. Why, because at the time there were significantly less people travelling by train and so there wouldn't have been the need for the number of seats that the lines now need. However since then most of the 390's which run on the WCML have been lengthened by 2 coaches to provide extra capacity to the line.

There has been nothing comparable to the Waterloo-Bournemouth-Weymouth arrangement since 1988. Kings Cross - Aberdeen continue with HSTs after electrification because they had been running on the ECML since 1979. The only other route where it would have made sense would have been Waterloo-Exeter if it had been decided to extend the electrification to Salisbury. So the answer to your last question is that the situation has never arisen where such an operation would have been appropriate. Additionally, it had long been accepted that limited diesel operation under the wires can be tolerated on the grounds of its claimed higher thermal efficiency and because it reduces demands on the overhead supply.

Electrical supply issues are fairly easy and cost effective to overcome IF there is the electric rolling stock to run on the lines. That is perhaps the main reason that we still see a lot of under wire running. In that to replace under the wire running we have to replace perfectly serviceable trains with new trains and then find something for the old trains to do.

It's one thing to free up some 90 mph DMU's which can easily be found work on other lines, it's quite another to find work for the HST's. Loco hauling on the Salisbury line would result in only a few coaches being dragged and would also mean that the services which split (part going to Exeter and part going to Bristol) would require careful thought. Nothing insurmountable but enough that it wouldn't justify the extra cost of buying locos and the extra line access charges for running them.

 

[HSTEd]

That is just totally untrue! How can you use the class 222 that was built 10 years as a comparison to fuel efficiency considering this does not have to comply with new emission regulations! The class 172 does comply with emisssion regs and has very bad fuel efficiency! A loco would be far more efficient on fuel as it is far easier to comply with emmisions regs on them so would need to be refueled less. Also the fuel tank on a loco is huge! Sorry but the anti loco brigade need to face facts too!!

Actually the MTU power plant used in the Class 172 has rather impressive fuel efficiency.

The primary problem that the new emissions regs is causing for DMUs is not anything to do with fuel consumption, but that power plants with sufficiently high power outputs are becoming difficult to fit into the volume available.
This is why we have not had a class of Turbostars with QSK-19s or similar in it yet.

The latest generation of technologies such as selective catalytic reduction should allow this restriction to be overcome and permit high power diesels to be built which are sufficiently compact. As appears to be the case with the engines for the IEP.

 

[LNW-GW Joint]

There are plenty of routes where you could have had EMU-drags, if they worked.

For example, Walsall to Rugeley, Oxted to Uckfield, Springburn to Cumbernauld (as well as extending electrified London trains beyond the wires to Blackpool, Shrewsbury, Lincoln etc).

Nobody seems to have been interested in this apparently reliable technology since the days of Class 33s (apart from the weekly 390 to Holyhead). That suggests that it wasn't quite as good.

One of the rather awkward problems with operating 390s away from the wires is the need to clear the routes first.
Virgin did this with Crewe-Holyhead (at considerable cost, especially with the low bridges between Crewe and Chester).
They also cleared for diversions the S&C and GSW routes and some other short stretches in the Midlands and North West.

I suspect this is at least one reason why 390s have never reached Shrewsbury or Blackpool.
Having too few of them was another.