The Anonymous Widower

Could Class 66 Locomotives Be Converted Into Battery-Electric Locomotives?

This picture shows a Freightliner Class 66 locomotive passing through Stratford with a multimodal freight train.

These are a few thoughts on converting some of the four hundred and eighty Class 66 locomotives into battery-electric trains.

An Estimate Of Performance Of A Battery Electric Class 66 Locomotive

In Iron Ore Miner Orders Heavy-Haul Battery Locomotive, I said this about a UK-sized locomotive based on Wabtec’s FLXdrive battery-electric technology.

I could envisage Wabtec designing a UK-sized battery-electric locomotive with these characteristics.

  • 2.5 MW power output, which is similar to a Class 66 locomotive.
  • A battery size of perhaps 1.8 MWh based on Wabtec’s  FLXdrive technology.
  • A pantograph to charge the batteries and also power the locomotive where electrification exists.
  • 75 mph operating speed.
  • Ability to work in tandem with a Class 66 locomotive.

All technology is under Wabtec’s control.

This locomotive could have a range of at least fifty miles on battery power, doing the sort of duties that Class 66 locomotives do!

So it would be able to take a multimodal container train out of the Port of Felixstowe to the electrification at Ipswich.

The Class 66 Locomotive Is Diesel-Electric

The Class 66 locomotive is a diesel-electric locomotive, where the diesel engine drives an alternator, which generates electricity, which then powers the six traction motors, which are arranged, so that there is one on each of the six axles.

This should make conversion easier, as the heavy lump of the engine and the alternator would be replaced with a large number of lithium-ion batteries.

Wabtec Has A Modular Battery System

This article on Railway Age gives a lot of detail and several pictures of the modular FLXdrive battery system.

  • Each module is a 4.9 kWh battery, that weighs 72.6 Kg.
  • Batteries are arranged into strings, which feed the traction motors.
  • There is a sophisticated control system, which ensures that a module failure doesn’t disable the locomotive.
  • The battery system is air-cooled.

I would expect that Wabtec could arrange a number of modules in the stripped out body of a Class 66 locomotive.

The FLXdrive Battery System Handles Regenerative Barking

The Railway Age article says this.

Battery charging while the FLXdrive is operating occurs through regenerative dynamic braking.

This will certainly improve efficiency.

Could A Pantograph Be Fitted To A Class 66 Locomotive?

This picture of a Class 66 locomotive was taken at Peterborough.

Note the 25 KVAC overhead electrification and the gap between the wires and the roof of the locomotive.

I don’t think it would the toughest job to design a pantograph for a Class 66 locomotive.

What Would Be The Use Of A Battery Electric Class 66 Locomotive With A Fifty Mile Range?

I believe that a surprising number of duties currently handled by Class 66 locomotives could be performed by a battery-electric Class 66 locomotive.

  • The locomotives would effectively be electric locomotives with a last fifty mile capability.
  • The number of possible duties will increase as electrification increases.
  • They would be ideal to support track maintenance activities.
  • They would be a zero-carbon locomotive with a low noise footprint.

As I said earlier, they would be able to haul a heavy intermodal train out of the Port of Felixstowe.


I am not a lover of the smelly, noisy and polluting diesel Class 66 locomotives, but it does look it could be possible to convert some into battery-electric locomotives.

I wouldn’t be surprised to see Wabtec convert some Class 66 locomotives into battery-electric locomotives.

I also believe, that conversion of Class 66 locomotives to battery-electric operation could be the most affordable way to decarbonise the rail freight.

September 16, 2021 - Posted by | Transport/Travel | , , , , ,


  1. […] I also believe that the technology can be applied to existing locomotives as I outlined in Could Class 66 Locomotives Be Converted Into Battery-Electric Locomotives?. […]

    Pingback by ‘Dramatically More Powerful’: World’s First Battery-Electric Freight Train Unveiled « The Anonymous Widower | September 17, 2021 | Reply

  2. Rail Industry Association Why Rail Electrification ? page 39 ” The diesel tank on a class 66 freight locomotive stores 6,400 litres of diesel fuel and occupies 6.4 cubic meters. The data shows that storage of the same amount of energy would require hydrogen storage of 79 cubic meters. Alternatively, this would require 136 cubic meters or 350 tonnes of batteries “. I hope that helps you with your calculations for fifty miles. I recommend downloading the RIA WRE ? report
    P.S. there isn’t an easy why to type the cubed symbol on a Mac, I have to remap the keyboard so it should be 79m3 and 136m3 but with small 3s.

    Comment by jason leahy | September 20, 2021 | Reply

  3. […] into a battery electric locomotive. I wrote about it in FLXdrive ‘Electrifies’ Pittsburgh. In Could Class 66 Locomotives Be Converted Into Battery-Electric Locomotives?, I concluded that it might be possible to convert Class 66 locomotives into battery-electric […]

    Pingback by Freight On The East West Main Line « The Anonymous Widower | October 8, 2021 | Reply

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