Whether a bi-mode Voyager would have been possible when they were under construction

[D365]

That of course would give you a nicely integrated bi-mode like the 80x, but the more "blunt instrument" style of having completely separate diesel and electric drivetrains and control systems on the same unit* would have been possible for pretty much as long as DMUs and EMUs have been a thing.

Again, not possible. Multiple unit space limitations. Even if a dual system were somehow physically possible, the complexity of implementing such a system, and making it safe, would make it an absolute non-starter from an engineering perspective.

 

[Bletchleyite]

Again, not possible. Multiple unit space limitations. Even if a dual system were somehow physically possible, the complexity of implementing such a system, and making it safe, would make it an absolute non-starter from an engineering perspective.

What limitations? In what way couldn't you have a 5-car unit with 4 of the coaches being DMU coaches with an engine underneath and the fifth being a self contained power car such as those used on the Mk3 OHLE EMUs e.g. 321s and 319s?

Dual control was clearly possible as the Class 73 did it years ago. Not to mention other countries such as the 1980s AKN units in Hamburg.

If space was a constraint, you could have put the engine(s) above the floor as per the 210.

It is not difficult in the slightest. In the simplest sense, you put a diesel loco on one end and an electric on the other that can control each other and away you go (see: Class 43 and 91).

 

[Energy]

If space was a constraint, you could have put the engine(s) above the floor as per the 210.

Maybe have say 2 disabled toilets and 2 normal ones on a 5 car train instead of 5 disabled toilets? the freed up space on one of the cars can be for the pantograph and its transformers etc. underneath.

 

[D365]

What limitations? In what way couldn't you have a 5-car unit with 4 of the coaches being DMU coaches with an engine underneath and the fifth being a self contained power car such as those used on the Mk3 OHLE EMUs e.g. 321s and 319s?

Dual control was clearly possible as the Class 73 did it years ago. Not to mention other countries such as the 1980s AKN units in Hamburg.

If space was a constraint, you could have put the engine(s) above the floor as per the 210.

It is not difficult in the slightest.

Dual control in a locomotive, yes. But that’s significantly less complex than what would have been required on a four or five-car multiple unit.

The Voyagers are already space-inefficient with engines under the floor. I would dread to think how much platform length would be wasted with a dedicated engine compartment.

Unless I am mistaken, Hitachi only managed to develop a bi-mode by extending the carriages to 26 metres, and even then that required the interior floors within each carriage to be raised. The shorter Class 810 was only made possible from the experience that was gained through the Class 80x designs.

 

[Bletchleyite]

I'd say you were mistaken. The raised floors are because of the large engines - and Voyager floors are similarly raised for the same reason.

 

[edwin_m]

They managed to make a 91 and an HST power car run in multiple without major problems, and the Class 210 could allegedly multiple with a 317. So even with 1980s tech bi-mode was reasonably straightforward.

The "Project Thor" proposal was, I believe, to one car with a transformer instead of a diesel engine, as was later done with the 80x series. I can't see why that wouldn't have been possible when they were first built, except that Virgin were probably insisting on the ridiculously high power to weight ratio which required a large diesel in each car.

 

[D365]

They managed to make a 91 and an HST power car run in multiple without major problems, and the Class 210 could allegedly multiple with a 317. So even with 1980s tech bi-mode was reasonably straightforward.

The 91 and 43 weren’t multiple units, and the 210 certainly wasn’t a bi-mode on its own. I stand by my point that a high-speed bi-mode was not possible until circa ten years ago. Look at how quickly ”Project Thor” fell by the wayside once they realised, among other reasons, how costly it would be to adapt a 90s-designed DEMU.

 

[edwin_m]

The 91 and 43 weren’t multiple units, and the 210 certainly wasn’t a bi-mode on its own. I stand by my point that a high-speed bi-mode was not possible until circa ten years ago. Look at how quickly ”Project Thor” fell by the wayside once they realised, among other reasons, how costly it would be to adapt a 90s-designed DEMU.

Getting a new locomotive to multiple with one from a very different era, not to mention a different power source, was much more of a challenge than designing a bi-mode to work together from the start. Back to at least the early 80s BR talked from time to time about putting electric power cars on one end of HSTs.

The traction package on a Voyager came from Alstom and is a close relative of those on their EMUs. I believe the problems with Project Thor were partly due to having to feed large power cables through the train, and partly the politics that Bombardier wanted to use their own equipment from Sweden rather than going to Alstom (in Preston) again.

 

[LOL The Irony]

To answer the original question, Project Thor said yes. I reckon with a crystal ball, they would've been ordered with bi-modal capabilities or an ability to have them added at a later date (they were by coincidence it seems, designed with the latter available).

 

[edwin_m]

To answer the original question, Project Thor said yes. I reckon with a crystal ball, they would've been ordered with bi-modal capabilities or an ability to have them added at a later date (they were by coincidence it seems, designed with the latter available).

If they'd been designed with conversion in mind, they would have included the traction power cables through the train, or at least provision for adding them later.

 

[XAM2175]

To answer the original question, Project Thor said yes. I reckon with a crystal ball, they would've been ordered with bi-modal capabilities or an ability to have them added at a later date (they were by coincidence it seems, designed with the latter available).

If they'd been designed with conversion in mind, they would have included the traction power cables through the train, or at least provision for adding them later.

Bingo - they fact that they weren't built with a through-train traction power bus is pretty conclusive evidence, I think, that the idea of converting them in the future was either judged to be unlikely or simply not considered at all.

I'd also suggest that Project Thor said something more like "ehh, I guess we could?" than "yes".

 

[Bletchleyite]

Bingo - they fact that they weren't built with a through-train traction power bus is pretty conclusive evidence, I think, that the idea of converting them in the future was either judged to be unlikely or simply not considered at all.

Indeed not - because diesel running under the wires was simply not considered to be a problem, so why would you pay for it? - as I said, diesel was the amazing wonder fuel.

My view on this remains that it technically could have been done, if potentially in a fairly crude manner (e.g. a separate electric power car like 319s and 321s), but there was no political will for it to be done, so it wasn't.

 

[O L Leigh]

What's all this talk about not being able to route high voltage cables down the train? That sounds like "rose fertiliser" of the highest order.

How many EMUs have the pan and transformer on a trailer car and the motors distributed elsewhere through the train? And what of all those 3rd rail units that have a 750V DC cable running the entire length connecting the shoes together? Heck, all the 25kV AC Mk3 derived EMUs have the high tension cable running down through the passenger saloon between the seat backs. We're not talking about a 25kV AC bus like on Pendolini but a few hundred volts for the traction supply.

 

[Bletchleyite]

What's all this talk about not being able to route high voltage cables down the train? That sounds like "rose fertiliser" of the highest order.

How many EMUs have the pan and transformer on a trailer car and the motors distributed elsewhere through the train? And what of all those 3rd rail units that have a 750V DC cable running the entire length connecting the shoes together? Heck, all the 25kV AC Mk3 derived EMUs have the high tension cable running down through the passenger saloon between the seat backs. We're not talking about a 25kV AC bus like on Pendolini but a few hundred volts for the traction supply.

I don't think anyone is saying they couldn't, just that they chose not to.

 

[XAM2175]

What's all this talk about not being able to route high voltage cables down the train? That sounds like "rose fertiliser" of the highest order.

Has anybody said that?

The reason that the lack of traction power distribution complicated the e-Voyager project is that installing it would entail significant modifications to every vehicle in the set, which would be expensive and obviously also require that each set be out of service for a substantial amount of time. Entirely possible, but a bit more complex than "just put a pantograph on a new vehicle and drop it into the set" would suggest!

 

[Bletchleyite]

Has anybody said that?

The reason that the lack of traction power distribution complicated the e-Voyager project is that installing it would entail significant modifications to every vehicle in the set, which would be expensive and obviously also require that each set be out of service for a substantial amount of time. Entirely possible, but a bit more complex than "just put a pantograph on a new vehicle and drop it into the set" would suggest!

I suppose you could do it "on the cheap" by making the additional coach a self-contained electric power coach like the 319/321 power car, with pantograph, transformer, compressor and traction motors. The downside of this would be poor acceleration on electric power. But that way you'd only have to cross-feed hotel power which they already do.

Overall the Voyagers are old and sub-optimal in many ways. An order for the markedly better 80x to replace them (or any other suitable product that might come up) is just better overall.

 

[Ken H]

They managed to make a 91 and an HST power car run in multiple without major problems, and the Class 210 could allegedly multiple with a 317. So even with 1980s tech bi-mode was reasonably straightforward.

The "Project Thor" proposal was, I believe, to one car with a transformer instead of a diesel engine, as was later done with the 80x series. I can't see why that wouldn't have been possible when they were first built, except that Virgin were probably insisting on the ridiculously high power to weight ratio which required a large diesel in each car.

Didn't that use the tdm(3) via the lighting wires, the system that was developed for scotrail, and later used with DVT's(1) and electric locos on WCML(2)?
(3) tdm = time division multiplex
(1) DVT = Driving van trailer
(2) WCML = West Coast Main Line

== Doublepost prevention - post automatically merged: 3 Aug 2021 ==

I suppose you could do it "on the cheap" by making the additional coach a self-contained electric power coach like the 319/321 power car, with pantograph, transformer, compressor and traction motors. The downside of this would be poor acceleration on electric power. But that way you'd only have to cross-feed hotel power which they already do.

Overall the Voyagers are old and sub-optimal in many ways. An order for the markedly better 80x to replace them (or any other suitable product that might come up) is just better overall.

what route would they be suitable for in a cascade, or scrap??

 

[LOL The Irony]

If they'd been designed with conversion in mind, they would have included the traction power cables through the train, or at least provision for adding them later.

I said available, not already fitted (like slinging engines under Mk3 EMUs was something available). Also it's obvious Thor was never going to be as simple as building a bunch of pantograph cars and calling it a day. I was saying that all diesel electric trains have the ability operate off another electrical source, not originating from the prime mover, inherently built in (with suitable modifications, of course).

 

[Bletchleyite]

I said available, not already fitted (like slinging engines under Mk3 EMUs was something available). Also it's obvious Thor was never going to be as simple as building a bunch of pantograph cars and calling it a day. I was saying that all diesel electric trains have the ability operate off another electrical source, not originating from the prime mover, inherently built in (with suitable modifications, of course).

Overall it's probably easier converting EMUs to DMUs/bi-mode than the other way round (see 769 etc) because you've already got traction power distribution of some kind. But yes, you can achieve anything if you've got the money. The questionable thing was whether spending it on 20 year old units is worthwhile.

 

[O L Leigh]

I don't think anyone is saying they couldn't, just that they chose not to.

Has anybody said that?

I've heard it said in multiple locations and alluded to here also. I would just like someone somewhere to explain to me why this is believed to be the case when there are so many other classes of train which have exactly that sort of system.

The reason that the lack of traction power distribution complicated the e-Voyager project is that installing it would entail significant modifications to every vehicle in the set, which would be expensive and obviously also require that each set be out of service for a substantial amount of time. Entirely possible, but a bit more complex than "just put a pantograph on a new vehicle and drop it into the set" would suggest!

Yes I am aware of the complexity of the proposal and that it would involve more than just dropping a new car into each set. However, I disagree that the amount of modifications required are "significant" or beyond the scope of a heavy overhaul. We're primarily talking about installing the cabling and control equipment to permit distributed power and traction changeovers on the move together with some additional switches and indications in the cab. Given that Project Thor was intending to go to all the trouble of building additional cars I hardly think that the need to modify the existing vehicles was going to be the reason why it all got kicked into the long grass.

 

[edwin_m]

Yes I am aware of the complexity of the proposal and that it would involve more than just dropping a new car into each set. However, I disagree that the amount of modifications required are "significant" or beyond the scope of a heavy overhaul. We're primarily talking about installing the cabling and control equipment to permit distributed power and traction changeovers on the move together with some additional switches and indications in the cab. Given that Project Thor was intending to go to all the trouble of building additional cars I hardly think that the need to modify the existing vehicles was going to be the reason why it all got kicked into the long grass.

I'm guessing that there would be two traction cables, each about an inch in diameter, with a minimum turning radius of several inches, and possible electromagnetic compatiblity issues if routed alongside other cables. As no space was left for these, I imagine a lot of the interior would need stripping out to install the necessary ducting.

 

[tomuk]

You could run the cables along the roof. Also in some designs the cables are multiple thinner cables. And if you were doing a rebuild/refurb of the voyagers you would want to strip the interiors anyway and hopefully rationalise the multiple toilets.

 

[Bletchleyite]

You could run the cables along the roof. Also in some designs the cables are multiple thinner cables. And if you were doing a rebuild/refurb of the voyagers you would want to strip the interiors anyway and hopefully rationalise the multiple toilets.

There are lots of things you could do - the thing is it's not worth doing it to a 20 year old train with lots of design flaws.

 

[tomuk]

There are lots of things you could do - the thing is it's not worth doing it to a 20 year old train with lots of design flaws.

Well this is the speculative ideas forum.

 

[LOL The Irony]

and hopefully rationalise the multiple toilets.

Wasn't it found to be incredibly difficult to cut holes in their bodyshells? You'd only be able to put extra luggage or bike spaces there.

 

[Bletchleyite]

Wasn't it found to be incredibly difficult to cut holes in their bodyshells? You'd only be able to put extra luggage or bike spaces there.

Voyagers are certainly short of luggage space (due to the uselessly small overheads) so that would help!

 

[507020]

There are lots of things you could do - the thing is it's not worth doing it to a 20 year old train with lots of design flaws.

If it was worth doing to the 30 year old 319s why isn’t it worth doing to the Voyagers?

 

[Bletchleyite]

If it was worth doing to the 30 year old 319s why isn’t it worth doing to the Voyagers?

Because the need is different (and the conversion the opposite way). There's a massive shortage of regional DMUs but not of long distance trains.

 

[D365]

Well this is the speculative ideas forum.

And I started the thread to determine whether or not the Voyagers could realistically have been built as high-speed bi-modes with the technology that ws available in the late 90s.

 

[Bletchleyite]

And I started the thread to determine whether or not the Voyagers could realistically have been built as high-speed bi-modes with the technology that ws available in the late 90s.

I think the conclusion would logically be yes, but they would have looked a bit different due to the kit not being quite as compact, perhaps some of it would have needed to be above the floor.