The Anonymous Widower

HybridFLEX Battery-Diesel Train Continues Programme Of Testing

The title of this post, is the same as that of this article on Global Railway Review.

This is the first two paragraphs.

The HybridFLEX battery-diesel train is currently undertaking a programme of tests between Duffield and Wirksworth, prior to returning to Chiltern Railways in the summer.

Fitted with a Rolls Royce MTU hybrid drive, the HybridFLEX will cut noise emissions in stations and deliver zero emissions when operating under battery power.

All seems to be going well, according to the article.

I like the concept, as to replace a diesel engine with a diesel-battery hybrid power pack must surely be a sensible way to at least partially decarbonise.

In the UK, the following diesel multiple units are fitted with modern MTU engines and could be candidates from a replacement power pack.

That is a total of 990 diesel engines.

As some of the Class 196 and Class 197 trains have yet to be delivered, I do wonder, if it would be sensible to deliver them as diesel-battery hybrid trains.



May 29, 2021 - Posted by | Transport/Travel | , , , , ,


  1. Any idea of the weight increase implicit in going from diesel to diesel-battery and the fuel increment for propelling that additional weight -before estimating for delivery to site and spares the power needed to build the batteries with all the additional control gear?

    Comment by Thomas Carr | May 30, 2021 | Reply

    • I have talked to engineers developing battery trains and they try to design without any weight increase. This also make certification easier. It is often done, when planes are fitted with different engines.

      Comment by AnonW | May 30, 2021 | Reply

  2. These trains are supposed to be operational about now, Sept 2021.
    What is the range under battery?

    I assume they will run on battery from Marylebone, through the tunnels and then onto diesel to Aylesbury. So battery at the London end and in stations.

    Reading the press today, one MP says that HS2 ph 1, will not be finished for 20 years – being informed by a high up whistle-blower. The Eastern leg appears dead in the water. The HS2 Chiltern tunnels to Amersham are underway with it highly likely they would be completed.

    What struck me, if ph. 1 is 20 years away the tunnels could be used in the interim by Chiltern services to Birmingham and Aylesbury using these HybridFlex trains in London then through the HS2 Chiltern tunnels all under battery, then switching to diesel at Amersham. Doing this may terminate HS2 at Aylesbury with the rest being canned for good, with HS2 track running onto the Chiltern Line at Aylesbury. A face saver for HMG, who want a get out for HS2 post Covid – so it appears.

    All Birmingham/W Mids trains could use this relieving the WCML. The London-Birmingham journey times should be excellent, as good as circuitous HS2, as the Chiltern is a direct route.

    A useful addition would be a branch at Aylesbury that could run onto only forty miles of reused Gt.Central trackbed running onto the WCML at Rugby, giving the WCML two extra tracks to London. South of Rugby the WCML then would have no capacity issues whatsoever.

    Comment by John | September 24, 2021 | Reply

  3. Finally the Class 168 equipped with HybridFLEX is in passenger service.

    Comment by fammorris | February 10, 2022 | Reply

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