The Anonymous Widower

Chiltern Electrification Alternatives Studied

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

These are the first two paragraphs.

Chiltern Railways is working to present the Department for Transport with options for a fleet renewal programme, with London Marylebone being the only non-electrified London terminal and pressure for the withdrawal of diesel trains continuing to mount, particularly from local residents.

Industry insiders report that this could see at least the 39 two and three-car Class 165 diesel multiple-units replaced.


  1. The Class 165 trains were built in 1990-1992 and refurbished around the turn of the century.
  2. Chiltern Railways have 28 two-car and 11 three-car Class 165 trains.
  3. Chiltern Railways also have ten similar two-car,  nine three-car and nine four-car Class 168 trains.
  4. In addition, Great Western Railway has 20 two-car and 16 three-car Class 165 trains, and 23 Class 166 trains.
  5. The Class 165 and Class 166 trains are 90 mph units, whereas the Class 168 trains are 100 mph units.

As Chiltern’s study would appear to rule out electrification, could all of these trains be replaced with an appropriate number of a new class of 100 mph  zero-carbon independently-powered multiple units?

In Alstom And Eversholt Rail Sign An Agreement For The UK’s First Ever Brand-New Hydrogen Train Fleet, I talked about a proposed hydrogen train fleet.

These trains are described as three-car in Alstom’s press release.

  • Most Aventras are 100 mph trains.
  • They could easily be lengthened to four cars by the addition of an extra car.
  • It may even be possible, that these trains could be fitted with a pantograph for working on electrified lines.

The only problem, I can envisage, is that a two-car version might not have enough space for the hydrogen and electrical gubbins.

Chiltern’s Locomotive-Hauled Mark III Stock

Greater Anglia have replaced locomotive-hauled Mark III stock with multiple units and it appears to have been successful.

Could Chiltern’s locomotive-hauled Mark III stock be replaced by six-car hydrogen-powered Aventras, with a long-distance interior?

Other Routes

Alstom and Eversholt Rail announced their agreement in November 2021.

Since then, I have written these posts, where the proposed Alstom Hydrogen Aventra could have an application.


  1. A two-car version would surely increase the number of applications.
  2. A 110 mph capability would allow the trains to mix it with high speed trains on fast lines.
  3. Bombardier proposed a 125 mph bi-mode Aventra. Could this be achieved with hydrogen power?

I feel the eight applications, I listed, could be the start of something a lot bigger.


Alstom and Eversholt Rail Group appear to have done their research.









May 17, 2023 - Posted by | Hydrogen, Transport/Travel | , , , , , , , , ,


  1. You wonder what the vehicle manufacturers offered when Chiltern went out to the industry last September for expressions of interest for battery electric multiple units.

    Comment by fammorris | May 17, 2023 | Reply

    • I wouldn’t be surprised that they didn’t get a serious bid, as the amount of power needed to electrify Marylebone for large numbers of battery electric trains could well be very difficult.

      If they had had a feasible bid, I suspect this story wouldn’t be in the media.

      Hydrogen probably has a one-fill-and-run-all-day range. Chiltern could probably put their own electrolyser at Banbury.

      Comment by AnonW | May 17, 2023 | Reply

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