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.