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Creation of class 230 DEMUs from ex-LU D78s by Vivarail

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Xenophon PCDGS

Xenophon PCDGS

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Clip said:
And do you not think that Vivarail would've explored all this before settling on the engine they have?
Click to expand...

Some of us are less privy to the internal machinations of Vivarail than others appear to be upon this particular thread.

Mind you, we must always be aware of this company's long and distinguished career in railway projects since they were formed ....in 2012.<(
 
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WatcherZero

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Greybeard33 said:
If Wikipedia is to be believed, Vivarail has selected the 3.2L Ford Duratorq TDCi inline-five turbo intercooled engine, with a nominal rating of 200hp, used in the Ford Transit and Ford Ranger.
http://en.wikipedia.org/wiki/Ford_Duratorq_engine
This engine does not appear to be available in the UK Transit, but the Ford spec for the US model quotes only 185hp @ 3000rpm, i.e. 7.5% derated.
http://www.ford.com/trucks/transitvanwagon/specifications/engine/
I guess Vivarail might also choose to derate it, trading acceleration for durability, depending on the results of performance testing on the D78 prototype.
Click to expand...

The 15hp is probably simply down to lower quality of US fuels with lower Octane/Cetane levels than European standards.
 
HSTEd

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Additionally the engine will not be called upon to deliver maximum power for a significant fraction of the acceleration of the train (while starting) as the DEMU transmission will not be able to put all the power down without wheelslip.

800hp on a ~75t train (after the engines and other bits are added) will translate to something like 10.7hp/t, which is actually superior to a Class 170 (~9.3hp/t) so I would expect stress on the engine to be significantly lower. It is also much higher than a pacer (~8.3hp/t) which seems to indicate that the train may be able to match or exceed pacer performance (low speed performance will be better as more axles are motored on the D-stock) even if the engines are never stressed above ~80% load.
 
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Clip

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Paul Sidorczuk said:
Some of us are less privy to the internal machinations of Vivarail than others appear to be upon this particular thread.

Mind you, we must always be aware of this company's long and distinguished career in railway projects since they were formed ....in 2012.<(
Click to expand...

I don think any of us know more than the other however it stands to sensible reason that they would've done research on this before even putting the whole concept out in the public doesn't it?

For your second point I think you are being disingenuous again given that the chairman of Vivarail has many many years in the rail industry and I would say, knows absolutely what he is talking about and doing more than most on this whole forum.
 
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Bantamzen

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Clip said:
I don think any of us know more than the other however it stands to sensible reason that they would've done research on this before even putting the whole concept out in the public doesn't it?

For your second point I think you are being disingenuous again given that the chairman of Vivarail has many many years in the rail industry and I would say, knows absolutely what he is talking about and doing more than most on this whole forum.
Click to expand...

I'm sure the chairman will be flattered by your faith in his experience, but even the most experienced business people can make mistakes, it's not a guaranteed recipe for success.

Nothing I have read in recent days has made me feel any different to how I have about this project, indeed the debate on the potential performance of the automotive power units has made me slightly more cynical still. We must not lose sight of the fact that the D78s are meant to be a cheap alternative to buying new stock. And usually when a project like this runs on a cheap(er) budget, there are always trade offs. We already know about the maximum speed trade, so one wonders what others there might be. Remember even if this project doesn't lead to any sales, they still have the scrap value of the D-stock so they don't stand to lose everything which might mean they are not adverse to cutting a few corners & hoping the PR does the work. Working in the public sector as I do and having been involved with many projects, I know only too well how ones based on a promise of a smaller budget have a habit of becoming something of, if you excuse the pun, a trainwreck. Cheaper is not always better.
 
Xenophon PCDGS

Xenophon PCDGS

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:D
Clip said:
For your second point I think you are being disingenuous again given that the chairman of Vivarail has many many years in the rail industry and I would say, knows absolutely what he is talking about and doing more than most on this whole forum.
Click to expand...

The knowledge of one man does not transpose itself automatically upon his workforce who work upon his great scheme of things.

The last person who met that specification was called Jesus....:D
 
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samuelmorris

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On the reliability front, I am informed that this particular example isn't especially reliable in the automotive application, let alone for railway applications. I'm slightly sceptical :p
 
Mikey C

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Bantamzen said:
I'm sure the chairman will be flattered by your faith in his experience, but even the most experienced business people can make mistakes, it's not a guaranteed recipe for success.

Nothing I have read in recent days has made me feel any different to how I have about this project, indeed the debate on the potential performance of the automotive power units has made me slightly more cynical still. We must not lose sight of the fact that the D78s are meant to be a cheap alternative to buying new stock. And usually when a project like this runs on a cheap(er) budget, there are always trade offs. We already know about the maximum speed trade, so one wonders what others there might be. Remember even if this project doesn't lead to any sales, they still have the scrap value of the D-stock so they don't stand to lose everything which might mean they are not adverse to cutting a few corners & hoping the PR does the work. Working in the public sector as I do and having been involved with many projects, I know only too well how ones based on a promise of a smaller budget have a habit of becoming something of, if you excuse the pun, a trainwreck. Cheaper is not always better.
Click to expand...

But then currently there aren't any new trains available, the 172s don't have valid engines for emission purposes, and are arguably "too much train" for Pacer replacement purposes on many lightly loaded short routes.
 
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Paul Sidorczuk said:
As the thread specific to the Class 319 units is still open, why is the need felt to use this D78 thread to discuss the Class 319 units?
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Agreed.

I have moved various posts regarding the 319 cascade to 319 cascade to Northern

Can I ask that if anyone wishes to discuss something other than the D78 stock, such as a suggestion to use alternative stock, that a new thread is created. If someone has already made a posting you wish to expand upon, feel free to click quote and copy the quote into your new thread. I do not wish to discourage such posts in any way; they just need to be in a relevant thread.

If there is already a relevant thread (such as in the case of 319 cascades) please use the alternative thread rather than create a new one.

This will be much easier than me having to try to figure out which posts to move (and I've not been following this thread so I could easily make a mistake!) and then move them to the appropriate thread and then tidy up posts referring to the fact people have used the wrong thread.

Also if you spot off-topic posts please click on the first one you spot as being off-topic and use the report button (
report.gif
) and let us know which post(s) are heading off topic and, if applicable, which thread they are best moved to. We would really prefer this be avoided if possible though!

Thanks in advance! :)

Now, back to the D78s....
 
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pemma

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Mikey C said:
But then currently there aren't any new trains available, the 172s don't have valid engines for emission purposes, and are arguably "too much train" for Pacer replacement purposes on many lightly loaded short routes.
Click to expand...

I'm not sure what's it like on the routes FGW use Pacers on but on most of the routes Northern use Pacers at peak times services are either a horrendously overcrowded 2 car Pacer or a longer formation, so 2-3 car 23m trains would be ideal replacement. (A 3 car 23m train being similar in length to a 4 car Pacer.) 2 car D-Trains would be a bad either unless you propose them as class 153 replacement on low usage branch lines.

I think all the ATW Pacer services will be switching to EMU so they aren't really relevant when talking about diesel replacements.
 
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Xenophon PCDGS

Xenophon PCDGS

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Mikey C said:
But then currently there aren't any new trains available, the 172s don't have valid engines for emission purposes, and are arguably "too much train" for Pacer replacement purposes on many lightly loaded short routes.
Click to expand...

There have been those in the "southern hemisphere" of Britain who have tried to make the point that these D78 unit proposals are not just to be regarded as "Pacer replacements" for Northern Rail, but available for all areas of Britain.

Living as I do in the north of England, albeit in an extremely affluent area that can give areas in the Home Counties a financial "run for their money", I am somewhat intrigued to hear of your mention of "Pacer operated lightly loaded short routes". Would you be so kind as to educate us by informing us what these routes actually are.
 
Buttsy

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Looking at the rail map, I feel that the D78s will potentially be of best use on the following routes (disregarding micro-fleets within TOCs, future electrification and hill-climbing capabilities):

St Ives
Falmouth
Looe
Gunnislake
Exmouth - Exeter
Fishguard - Carmarthen
Pembroke Dock - Carmarthen
Milford Haven - Carmarthen
Heart Of Wales
Severn Beach once Filton Bank quadrupled
Valley lines
Thames Valley branches
Romsey '6'
Lymington (leaving shoegear in place)! ;)
Lincs away from Nottingham/Sheffield - Skegness/Cleethorpes
Nottingham - Worksop
Matlock
Norfolk branches
Felixtowe
Hull - Scarborough
Penistone
Knottingley - Leeds/Wakefield
Colne
Preston - Ormskirk
Blackpool South (only as a shuttle to Kirkham probably)
Morecambe
Windermere shuttles
Cumbrian coast
Far North lines
West Highland lines
Queen Street High Level - Anniesland
Paisley Canal
Borderlands line
Blaenau line
Llandudno shuttles
Ellesmere Port - Helsby
Ivanhoe line (if there is sufficient amount of 3/4 tracking)
Manchester South surburban through Romiley, but no further than New Mills
Stockport - Stalybridge (improved service)
Bishops - Saltburn

No doubt there will be reasons why certain of these routes wouldn't work and I may have missed a couple of obvious routes. Some of the above would be short-term measures to allow capacity enhancements elsewhere while awaiting electrification.
 
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pemma

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Buttsy said:
Ellesmere Port - Helsby
Stockport - Stalybridge (improved service)
Click to expand...

Giving Denton a direct service to Victoria would probably be more useful than a regular one to Stalybridge. It's not proposed the Victoria only TPE services will call at Stalybridge under the new service pattern so moving TPE services to Victoria won't strengthen the case for a regular Stockport - Stalybridge service.

Although, I think those two are particularly good examples of where converted D78s could be used. An hourly service using a converted D78 would be much better than an irregular service using Pacers/Sprinters.
 
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I do not think these units would be suitable for the West Highland lines they are intended for high density urban routes and could well be a good replacement for pacers.
 
Buttsy

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WatcherZero said:
Some obvious ones would be 60mph trains on 100mph routes.
Click to expand...

As it has been commented on before, the impact on an 100mph route starts to become relevant if the timetabled top speed of a 75mph unit currently used is likely to exceed around 55mph between stops.
 
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Wolfie

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Paul Sidorczuk said:
Some of us are less privy to the internal machinations of Vivarail than others appear to be upon this particular thread.

Mind you, we must always be aware of this company's long and distinguished career in railway projects since they were formed ....in 2012.<(
Click to expand...

my bold

... and of course such a long established and distinguished career in railway projects always guarantees success... I give you Ansaldo Breda...!<D;):D
 
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Buttsy said:
Looking at the rail map, I feel that the D78s will potentially be of best use on the following routes (disregarding micro-fleets within TOCs, future electrification and hill-climbing capabilities):
...
Lincs away from Nottingham/Sheffield - Skegness/Cleethorpes
...
Hull - Scarborough
...

No doubt there will be reasons why certain of these routes wouldn't work and I may have missed a couple of obvious routes. Some of the above would be short-term measures to allow capacity enhancements elsewhere while awaiting electrification.
Click to expand...

Cleethorpes to Doncaster is slow enough for a D-Train to run.
And the section to Sheffield isn't much faster.
And Hull to Scarborough line trains often run to Sheffield or York so this will eliminate the section of fast running northeast of Doncaster if D-Trains run current routes.
 
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Greybeard33

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Clip said:
And do you not think that Vivarail would've explored all this before settling on the engine they have?

Or do you think they just popped down to Dagenham one day and picked the first one they saw?
Click to expand...
I would be surprised if Vivarail's engineers have not satisfied themselves that the engine is up to the job (and that the existing D78 bogies, wheelsets and traction motors are suitable for prolonged running at 60mph). However, a long career as a professional engineer (though not in the rail or automotive industries) has convinced me of the truth of the old adage "the devil is in the detail". A novel concept can look great on the PowerPoint slides at the project definition stage, but then turn out to have a fatal flaw when it gets to development testing or (worse) not until after entry into operational service. If engineers were omniscient and infallible, it would not be necessary to test a prototype - everything would work perfectly first time!

The risk of unforeseen snags is increased when existing, "proven", components are reused in a different operational environment to that for which they were designed.
HSTEd said:
Additionally the engine will not be called upon to deliver maximum power for a significant fraction of the acceleration of the train (while starting) as the DEMU transmission will not be able to put all the power down without wheelslip.

800hp on a ~75t train (after the engines and other bits are added) will translate to something like 10.7hp/t, which is actually superior to a Class 170 (~9.3hp/t) so I would expect stress on the engine to be significantly lower. It is also much higher than a pacer (~8.3hp/t) which seems to indicate that the train may be able to match or exceed pacer performance (low speed performance will be better as more axles are motored on the D-stock) even if the engines are never stressed above ~80% load.
Click to expand...
Wheelslip is normally only limiting for a short time when starting from a stand. As speed increases, the axle torque needed to deliver a given power falls and available power becomes the limiting factor.

For performance calculations, it is the maximum gross weight of the train, including full payload, that matters, not the operating weight empty. So the differences in relative power/weight ratio are less than you suggest. In any case Vivarail is relying on higher acceleration to enable the 60mph D-train to match the time between stops of a 75mph Pacer on some routes.
 
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brianthegiant

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prototypes are a dwindling approach, expensive way to test a concept and what if the fundamentals turn out to be flawed - build another prototype?
From my understanding these days its all about 3D CAD and simulation, from electronics to aeronautical.
 
Domh245

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Certainly CAD and simulation is the way forward, but a simulation is only as good as the model used to simulate! There are occasionally no substitutes for building a real prototype. It should however be able to cut down the number of prototypes you need to build though, if the model is of a high enough quality, you should be able to build your prototype, confirm that everything matches your simulated behaviour, and off to production you go!
 
Nym

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brianthegiant said:
prototypes are a dwindling approach, expensive way to test a concept and what if the fundamentals turn out to be flawed - build another prototype?
From my understanding these days its all about 3D CAD and simulation, from electronics to aeronautical.
Click to expand...

Given the amount of times I've seen a CAD model done internally, externally by several companies, even doing it myself, it rarely works properly. (Most of the models I do are as a result of measurement, then checked against a drawing)

There is no substitute for prototyping and placing it on the train, even for 'one off' fits of 2 or 3 units, I always encourage the use of true prototyping and offering in position.

If one doesn't go as far as to do that, then actually looking at the train is a must, one engineer on my team doing a 2 unit fit with me doesn't like going to the train to actually measure something, I do not expect that his design will fit 1st time if it is designed from the drawings alone, and will be insistent on a prototype in foam core or similar.
 
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swt_passenger

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The Northern ITT (being discussed in the latest thread) now appears to explicitly rule out these conversions being used in that franchise.

So will they go ahead with the demonstrator now/
 
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The BBC News web site has an item on Pacer replacement, including the conversion of D78 stock, liberally sprinkled with the term 'commuter' meaning all rail passengers!
 
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swt_passenger said:
The Northern ITT (being discussed in the latest thread) now appears to explicitly rule out these conversions being used in that franchise.

So will they go ahead with the demonstrator now/
Click to expand...

Based on what is posted on that thread, the new trains required by the ITT are fewer than the Pacers to be withdrawn, and there are also significant service expansions proposed on many of the diesel routes for which extra trains will have to be found. Therefore I think there is still potentially a role for D78s somewhere in the mix.
 
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