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Tuesday 12 October 2010

Prius On Rails

While checking sources for last week’s post on the fall-out from cancellation of the Third Tagus Crossing, and its implication for high speed rail travel in Portugal, I came across some blurb for a hybrid high speed train. What that? Well, this is an electric train that can also run under its own power on lines where there is no electrification.

And that is a question that has recently taxed the Department for Transport (aka DaFT), and preferred supplier Hitachi, over the saga of new so-called “bi-mode” trains, which may never see the light of day as a result of spending cuts. Astonishingly, some in the industry who should know better are championing a new build of electric locomotives instead, although how that powers trains where there are no overhead wires is not explained.

Once again, the company behind the hybrid high speed train is our old friends Patentes Talgo. No, I am not being paid a retainer by them, but yes, perhaps I should put in for one. The concept is simple: a proven existing design [pictured], which can operate on different track gauges, has its present end coaches replaced by what the blurb quaintly calls “Technical End Coaches”. These house a diesel engine.

A Talgo 250 pauses at Aranjuez

As the power generated by the diesel engine is transmitted via the traction equipment in the existing power cars, the weight of these new coaches is kept down. The engine itself is the same MTU V12 used in a variety of traction applications – such as the recent refurbishment of the UK’s InterCity 125 power cars. It’s established technology.

But is it a practical proposition? A first look at the blurb did leave me wondering whether the axle load would stay low – very important for higher speeds – and there is a trade-off of some passenger accommodation, with a resulting higher proportion of what we would call Standard Class seating, but the fact of the matter is that the order has been placed, and the trains are slated to start operation in 2012.

Top whack on the high speed network will remain 250km/h, with 220 on conventional electric lines, and 180 is claimed for diesel operation. The trains will run out of Madrid to destinations such as Algeciras and Cartagena – well off the wires. Journey times will be better than using hauled sets, because of higher speeds and quicker gauge changing, and there will be better use of capacity at busy terminal stations such as Madrid Atocha.

Will it work? Well, Talgo have already done some work on high speed diesel trains, so the prognosis is good. Once again, while we in the UK debate the concept, someone else just goes ahead and does it.

[The PDF with detail of the hybrid train is HERE. In English!]

1 comment:

Andy R said...

I've used the Talgos to Cartagena many times myself and it would be interesting to know where these sets will be coming off the high speed line and taking to the conventional line. The high speed line is much further North than the much maligned conventional route via Chinchilla and Albacete and as such is even more of a detour. Can the higher speed offset that and does it make sense?