Irish Rail Bi-Mode Trains

[JD9948]

Hi Folks,

I was reading one of the leading rail magazines(Rail Express). In it’s most recent edition, in the “Irish Angle” section it stated that;

“Irish Rail and National Transport Authority(NTA) are considering the possibility of acquiring a fleet of bi-mode trains for service in the Greater Dublin Area. It is understood that the Diesel/Electric Units would be used to extend the existing DART services beyond the present electrified area to Drogheda and Maynooth. Around 100 vehicles have been mooted, and IR hopes to have the units in service within four years”.

I take great interest in Irish Railways but am definitley no expert. Do you guys think this will ever happen and what’s your opinion on this? Thanks a million.

JD9948

[Mark Gleeson]

No tender has been issued as such anything is speculation

In short its a bad idea

[James Shields]

Originally Posted by Mark Gleeson

No tender has been issued as such anything is speculation

In short its a bad idea

The speculation or the concept is a bad idea?

I know in the UK and other countries DEMUs are quite common, with a Diesel generator powering electric motors. It doesn't seem a huge stretch to have a Diesel generator and a pantograph the can pick up power from overhead lines where present, and a Diesel generator as backup where they aren't.

However, I expect every changeover will take a couple of minutes, so it seems pointless unless you have a substantial section of electrified track to run on.

[comcor]

The main use would seem to be if we are to have a very slow electrification program.

There's no point buying electrical until the power lines are in place.

There's no point having diesel after the lines are in place.

Normally, you would say to buy diesels and cascade them to areas where there is no electrification. That's not so easy, with the Cork Commuter service being the only significant operation outside Dublin suitable for Dublin's retired diesels. Even if massively expanded to double frequency and train capacity on current services it could take at most 15% of diesel railcars.

So in the absence of a big bang approach to electrification on the Dublin commuter network, hybrids become necessary.

[James Shields]

Thanks for the info. I see they are in use in a number of other countries.

Does anyone have experience of travelling on a bi-mode train? I'd be interested to hear how smooth the change-over process is.

[Jamie2k9]

Originally Posted by James Shields

Thanks for the info. I see they are in use in a number of other countries.

Does anyone have experience of travelling on a bi-mode train? I'd be interested to hear how smooth the change-over process is.

I traveled on the Great Western new express trains and the switch over was seamless. As soon as engines switch off the pantograph rises and train able to depart seconds lather. It was a calling point where the switch over happend but goes without saying it doesn't need to stop to facilitate the changeover.

Not experienced overhead to diesel yet.

[Mark Gleeson]

Problem with this is this is relatively unproven, heavy, expensive and more likely to break down.

Over any reasonable timeframe it is cheaper electrify and use a straight electric train.

We need a high performance 0-100kph in 35 seconds urban train, there is no way a DART with a few diesel engines under the floor can do that.

In the time it will take to order the trains, you would have electrified the Maynooth line, civil works reasonably quick, ordering and commissioning trains slow

This is classic government indecision, they won't authorize of the funding of the electrification but we know it has to happen and buying an urban diesel powered train right now is bad idea

[James Shields]

I see in France the SNCF B 82500 class EDMUs can operate on diesel, 1500V DC, or 25kV AC. That would certainly allow our main lines to be electrified on a phased basis, while still serving low traffic lines that would be unlikely to be viable for electrification for the foreseeable future.

[Eddie]

I have to say that I think it is a bad idea too for Ireland.

It shouldn't take any longer than 5 years to plan for and electrify a line. The lifespan of a train is significantly longer.

The Maynooth trains are relatively new (2005?) and I imagine displacing these to other parts of the network will be tricky enough, and the order time for any new ones will be long enough.

Let's just get on with the electrification programme and have some suitable electric trains ready.

[James Shields]

Crossed posts with Mark...

Most of the dual mode trains in use in other countries are long distance passenger or freight trains, and in many cases they have a small diesel generator so they can make it the last few kilometres on unelectrified tracks.

I agree it's a pointless idea for urban rail.

One interesting idea being tried in the UK is inserting an electric car with pantograph into the middle of an existing DEMU to turn it into an dual mode EDMU. As far as I know the 22Ks are straight DMUs rather than DEMUs, otherwise this might be an option for them.

[James Shields]

Originally Posted by Eddie

I have to say that I think it is a bad idea too for Ireland.

I would say bad idea for DART. Not necessarily bad idea for Ireland.

If we were looking at electrifying Dublin-Belfast and Dublin-Cork/Limerick, having stock that can operate on the electrified lines where present, and switch to diesel elsewhere. Of course there are no plans for electrification of those lines, but there should be.

[Thomas J Stamp]

it is cause and effect.

untill the abandonment of DART underground the IE plan for to order electric trains and have them running on the maynooth and northern line, which was due to the electrified at the same time.

since the government have in effect indefintaly postpose D-U IE have no choice but to go down this road in the hope that the lines will, one day, be electrified.