Should all new diesel trains be Bi-Modes?

[ooo]

As many services currently operated by diesel trains run under wires for at least some of their journey do you think there would be a benefit in having these trains as bi modes instead?

As more lines get electrified (hopefully) even more services will be running under wires causing unnecessary pollution and harm to already very polluted towns and cities.

 

[Bletchleyite]

Sorry, the subject doesn't tally with the vote?

So my views:-

All new DMUs should be bi-mode instead, with the engines and generating equipment fitted on rafts to allow replacement with future technologies e.g. batteries. They should also be dual power i.e. third rail and OHLE, much more flexible that way even if the shoes/pantographs are removed and stored.

New EMUs are fine (as above).

 

[ooo]

deleted

 

[class387]

Sorry about the confusion I agree it isn't the clearest poll but i can't seem to change it. I have tried to clarify the options at the top of the opening post.

Your title says Bimode vs EMU instead of EMU.

 

[ooo]

Your title says Bimode vs EMU instead of EMU.

I've changed the thread title so it should more sense now. Sorry about the confusion

 

[eastwestdivide]

Missing option: some and some

 

[Mordac]

I think politicians don't need any more excuses to cancel electrification schemes. Plus, bi-modes just have too many compromises. I do think where possible DMUs should be DEMUs, though.

 

[mallard]

Ideally, (almost) all rolling stock renewals would be accompanied by an extensive route modernisation (which would include electrification)...

However, there are routes where bi-modes make sense (e.g. the Devon/Cornwall route due to the impracticality of wiring the Dawlish sea wall) and routes where traffic levels are low enough (sub-hourly) to make wiring unjustified. We're still a few years away from practical battery electrics and hydrogen power, so for now there is a (limited) case for diesels. If they're not going to make use of electrical equipment, it doesn't make sense to carry it.

 

[ooo]

Missing option: some and some

Now added

 

[jimm]

Ideally, (almost) all rolling stock renewals would be accompanied by an extensive route modernisation (which would include electrification)...

However, there are routes where bi-modes make sense (e.g. the Devon/Cornwall route due to the impracticality of wiring the Dawlish sea wall) and routes where traffic levels are low enough (sub-hourly) to make wiring unjustified. We're still a few years away from practical battery electrics and hydrogen power, so for now there is a (limited) case for diesels. If they're not going to make use of electrical equipment, it doesn't make sense to carry it.

I'm not aware anyone has ever said that it would be impractical to electrify the line along the sea wall at Dawlish - electric trains run along the sea wall at Saltcoats in Ayrshire in all but the most extreme wind and wave conditions - see Google for umpteen pictures.

The portals there are pretty substantial structures by 1980s standards and more closely spaced than usual but no reason to suppose the same approach could not work at Dawlish.

 

[Railperf]

I would imagine a hybrid addition would be welcome. I.E a bi-mode with the ability to recuperate electrical power under braking and whilst under the overhead to top up batteries that you could then utilise that to enhance acceleration in diesel mode. Add a few shatterproof solar panels to the roof of the train, and in theory you could minimise the locations that you might need toelectrify. I have always believed that electrification is probably only essential when accelerating these trains from a standstill to their top speed. After that - unless the gradients are every adverse, much lower power requirement is needed to maintain the cruising speeds. But that would then add a requirement for maintenance staff and signallers to avoid slower running or out of course stops within the non-electrified areas!
As an example, HST's running to time from Reeading to Dicot only power up to somewhere over 110mph and then cruise to a standstill. So the overhead is only needed for part of that acceleration phase if there is enough battery juice to complete the acceleration. Or you could electrify the entire length of route where acceleration is needed and use the batteries and diesel power packs for areas away from the wires.

 

[PaxmanValenta]

My ambition is to see an HST2 developed. No long distance train developed in the last 25 years has been a suitable replacement to the class 43 HST. The Voyagers, Class 800s etc will never live up to the HST.
There is every possibility that a bi-mode HST2 could be developed. Diesel traction at both front and rear with electric traction in alternate coaches.

 

[D5645]

It would make sense to have no further DMU orders and specify bi-modes instead.

I find it frustrating that we are so far behind other European railways when it comes to electrification.

The most efficient way to move large numbers of people around is by EMU.

 

[BigCj34]

Is there a significant cost and weight difference and between building a bi-mode and a diesel only train? If not, then it's something that may as well be done.

For a franchise like XC with many diesel trains running under wires it would make perfect sense, it's a sham project Thor got cancelled for that reason. I have no idea how the economics stacked up with that though.

 

[TheWalrus]

I voted a mix of both as I think some lines will never be electrified, so the need for some diesels will always be there.

 

[sprinterguy]

My ambition is to see an HST2 developed. No long distance train developed in the last 25 years has been a suitable replacement to the class 43 HST. The Voyagers, Class 800s etc will never live up to the HST.
There is every possibility that a bi-mode HST2 could be developed. Diesel traction at both front and rear with electric traction in alternate coaches.

The IEP was originally designated as the HST2 Project and featured a separate diesel power car combined with distributed electric traction along the train on the bi-mode sets. The separate diesel power car was dispensed with as being less flexible/effective than underfloor diesel engines, so while it's certainly technically plausible it seems that ship has sailed.

Not least because the IET option has been designated as chosen traction for two inter-city main lines and is now available as an off-the-shelf product for the operators of other routes to follow suit. CSRE proposed their Polaris train with separate power cars and bi-mode capability for the UK market around 2010 but this offering seemed to die a death in the face of the subsequent confirmation of the IEP order.