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 locomotives.

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 should be able to haul a heavy intermodal train out of the Port of Felixstowe.

Would A Battery-Electric And A Diesel-Electric Class 66 Locomotive Working As A Pair Be Able to Handle The Heaviest Trains?

As the Americans and Canadians  have shown with more than one locomotive, where one is a battery-electric locomotive can reduce the carbon-emissions, the same rules must apply in the UK.


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 help decarbonise 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

    • Really good report, especially as it massages my ego regarding the volume and mass of alternative energy sources which I independently reached 😁. There still is the question of what contribution battery recharging under the wires or strategic stopping points can be made to the equation. Shame we can’t find a zero emissions fuel with all the attributes of diesel.

      Comment by fammorris | November 26, 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

  4. […] I discuss this in Could Class 66 Locomotives Be Converted Into Battery-Electric Locomotives? […]

    Pingback by Canadian National Buys Battery Locomotive « The Anonymous Widower | November 5, 2021 | Reply

  5. I saw this US article and it got me thinking about a long distance battery/diesel bi-mode.
    Why convert the Loco, why not put a 40 foot container or something similar filled with batteries and control gear on a flat bed wagon and couple it to the Loco. You might even do something more sophisticated and arrange some form of fast charging under the wires.

    Comment by fammorris | November 14, 2021 | Reply

    • I did a few calculations which indicated that a double locomotive; one diesel and one battery could make savings of fuel and CO2. But I didn’t publish.

      And now Wabtec are developing the concept. I suspect they’ve got some good people on the maths.

      Comment by AnonW | November 14, 2021 | Reply

    • fammorris, that article you quote is based on the Berkeley Lab research I cited in another post.

      That article/research is oriented to the US, where the issues are very different from here in GB. Distances are vast, and very little track is electrified. Plus, as the article says, most US locos have an electric motor powered by a diesel generator. Most British freight locos are pure diesel, and are also pretty ancient and need replacing. So I’d agree with you that there’s not much point converting them.

      I think I would have 2 basic questions about battery-driven locos: do they have the power to haul heavy freight trains? And what range do they need?

      From the article and from Wabtec’s loco, I think it’s clear the answer to the first is ‘yes’. Although GB is far behind most European countries in electrification, the answer to the second is ‘far less than needed in the US’. If you look at common freight routes, whether from ports like Southampton or Felixstowe to the Midlands, or from quarries in the Peaks or Mendips, most of them are at least partially electrified. I would doubt whether most freight routes need a range >100km provided batteries can be recharged on the electrified sections (or of course from braking power).

      So ISTM what’s needed are modern electric locos which can take electric power from the track where available, or from batteries when it’s not, and can recharge the batteries from both the wires and regen braking. Stadler’s German trial of their Flirts shows that 100km range can easily be reached with current battery tech, and the way they’ve organised this with their 755s with a separate power car means that the power car becomes like the ‘boxcar’ mentioned in the BL article – it can basically be as big as needed.

      Comment by Peter Robins | January 11, 2022 | Reply

      • You say most British freight locos are pure diesel, and are also pretty ancient and need replacing. Well it’s always better to buy the latest technology but to say a Class 68 or following classes is ancient rather overlooks the typical life of a locomotive. Yes everything before that including the 58, 59, 60 and 66 are, today, upwards of 30 years old but you still have some 40+ year old Class 56’s converted into Class 70 in the last decade. And of course they’re all diesel-electrics just like the American vehicles.
        Should we buy electric locos with a battery trailer, well why not, it would be better to get rid of diesel propulsion altogether. All we need is the money but as you can see from the Class 70 money for new locos isn’t always available.

        Comment by fammorris | January 11, 2022

      • well, yes, but then the diesels are going to have to be replaced anyway. If all the tracks are electrified, then they’ll have to buy electric locos. So the only questions are what the diesels are going to be replaced with, and who’s going to pay? Electric locos will be cheaper than electric+battery. Probably electric+battery will be cheaper than diesel to run. With track electrification, the taxpayer pays the cost, whereas with loco electrification, it’s the freight operators (and probably ultimately their customers) who pay.

        Comment by Peter Robins | January 11, 2022

  6. Velocys can produce sustainable net-zero diesel and there’s also HVO.

    Comment by AnonW | November 26, 2021 | Reply

    • I frankly think that SFAs and HVOs should form part of a practical solution to the continuing use of jet aircraft and diesel engine fuel substitutes. Despite the hype in the press I don’t expect their alternatives to reach a level of maturity overnight.
      Although I realise in the scheme of things we’ll never universally exclude harmful emissions in many processes, the one issue that still leaves me uneasy is the understanding of “net-zero” – perhaps it shouldn’t but for me it tends to smack of financial manipulation.

      Comment by fammorris | November 26, 2021 | Reply

      • I bought a few shares in Velocys, when I realised they had applied modern catalyst knowledge to the Fischer-Tropsch process. The trouble with this process is that it has been used by dodgy routines like Nazi Germany and South Africa under apartheid to make fuel from things like forest litter.

        Velocys are proposing to use household waste in their plant at Immingham and in the US, they are using waste wood in a plant in Mississippi.

        But there is one resource they are looking at, that currently goes into landfill or incinerators. And that is disposable nappies and other products of a similar ilk.

        I don’t know about where you live, but we separate our rubbish into three bins or bags. I can see Councils collecting nappies to make fuel. But I do feel it is fair to include avoidance of landfill in the benefits.

        Comment by AnonW | November 26, 2021

      • Each week we separate
        1. Recyclable plastics, tins and paper products from
        2. Non recyclables from
        3. Food waste.
        We also have a collection of garden waste every fortnight (something you don’t have to concern yourself with)
        There’s currently an IPO for a company who want to process plastics into synthetic oil to resell to the petrochemicals industry.

        Comment by fammorris | November 26, 2021

  7. I suspect that there are plenty of sources of non-recyclable plastics and waste, that can be ruined into sustainable aviation fuel and diesel and other products, that we currently get from fossil fuels.

    One person’s rubbish will be some company’s profit and the more technology we have, the better.

    Comment by AnonW | November 26, 2021 | Reply

  8. I came across press releases from Amtrak and Siemens announced last July for 58, diesel/catenary and 17, diesel/3rd rail/battery ALC-42e locos

    I know we’ve touched on the subject of a battery trailer car coupled with a Class 66, I have to say with a pinch of salt, but this truly is a case of the configuration actually being adopted.
    What’s also notable is that these trains will be employed on Amtrak Empire Service routes that in US terms are so short – the longest Maple Leaf cross border service is 544 miles, while the Ethan Allen Express to Vermont is about 280 miles.
    There’s a certain amount of ridicule on social media as to the configuration and no authoratative explanation as to a reason for the battery diesel hybrid. Nevertheless Siemens intend to start testing of the concept in 2025 and by 2030 they should be running.
    Given that the two tunnels involved in the approaches to New York’s Pennsylvania Street Station total more than 6 Kms, electrification of the last 64kms is largely 3rd rail with power capacity issues (rather like the Channel Tunnel – Waterloo link), and the track is owned by different companies, there’s no hope of a consolidated approach to optimising operations.
    Perhaps the Amtrak’s choice of the diesel/3rd rail/battery ALC-42e locos is not so silly.

    Comment by fammorris | January 20, 2022 | Reply

  9. Additional to my post on January 20th, it seems that Metra Rail in the States have been looking for statements of interest to convert 3300 hp Locos to battery propulsion. These would provide a direct parallel to the suggestion of converting Class 66 locos. So far no apparent progress.
    I accidentally also found a more definitive article on the Empire State Passenger Association (ESPA) website regarding Siemens ALC-42e battery hybrid. It states:
    …..”Seventeen Hybrid battery trainsets will be employed for the portion of the Amtrak fleet used on New York State’s Empire Corridor services connecting New York City with Upstate NY, Vermont, and Canada. These trainsets will have a standard Siemens diesel-electric Charger (the diesel engine providing the power for the traction motors) mated to rake of semi-permanently coupled Siemens Venture coaches with streamlined fronted cab car at the other end of the set, containing a control cab and a large battery pack. A prototype set is planned to be available for testing by 2025, with the rest of the trainsets being delivered by 2030.
    While the battery power will further boost the fuel efficiency of the diesel-electric train – reducing emissions further – its primary purpose is to allow the trains to run in the tunnels of Penn Station and Grand Central Terminal off electrical power, the diesel engine switched off. The large battery replaces the use of third rail today by the current fleet of General Electric P32AC-DM Genesis dual-mode locomotives that hauls Empire Corridor trains. Amtrak therefore avoids the cost of using of power from the third rail DC power of the LIRR and Metro-North, and the complication of the two different types of third rail used by the two commuter railroads, which requires the switching of third rail shoes when trains are diverted from using one terminal to the other Manhattan station.”
    Reports about the retention of 3rd rail traction are therefore wrong.
    Maybe not a configuration for freight but if we run passenger services using a diesel-electric loco a driving van trailer fitted at the other end could be a candidate for the installation of batteries.

    Comment by fammorris | January 21, 2022 | Reply

    • I think we can be assured that clever engineers in companies like Rolls-Royce, mtu, Stadler, Wabtec, Siemens, Alstom, Cummins, Direct Rail Services, Tesco et al are drinking gallons of real ale or the local equivalent, whilst working hard to develop the solution to decarbonising freight.

      Consider that 3,300 horse power is 2,500 kW and is a typical size for a diesel locomotive power unit. What size is the Rolls-Royce beer-keg sized generator? 2,500 kW. Coincidence or design? I added Direct Rail Services and Tesco to my list, as these two companies are freight transport innovators and I reckon they are plotting the next phase of rail decarbonisation for the publicity. I would expect an order from this direction for hydrogen-powered freight locomotives this year. If not hydrogen, what about a gas-turbine powered Class 68, running on sustainable aviation fuel?

      Comment by AnonW | January 21, 2022 | Reply

      • I’m sure that Rolls-Royce and its clever engineers are beavering away in the cause of decarbonisation yet APT aside over 40 years ago, in the last 25 years they don’t seem to have made much headway with the gas turbine for rail. And that’s with the benefit of living over the road from Britain’s original railway technological centre. 😉

        Comment by fammorris | January 21, 2022

  10. […] I laid out my thoughts in Could Class 66 Locomotives Be Converted Into Battery-Electric Locomotives?. […]

    Pingback by Fortescue Unveils World-First Electric Train Using Gravity To Recharge « The Anonymous Widower | March 2, 2022 | Reply

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: