The Anonymous Widower

Battery EMUs Envisaged In Southeastern Fleet Procurement

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

This is the first paragraph.

Southeastern has invited expressions of interest for the supply of new electric multiple-units with an optional battery capability for operation away from the 750 V DC third-rail network.

This article on bidstats is entitled Supply Of And Maintenance Support For New Rolling Stock For Southeastern, and gives more details.

These are my thoughts.

Southeastern HighSpeed Services

There would appear to be no changes in this contract to the Class 395 trains, that work on High Speed One, as this is said in the bidstats article.

Full compatibility with Southeastern infrastructure (excluding High Speed 1 infrastructure)

which appears to rule out running on High Speed One.

In addition, this article on Rail Magazine is entitled Southeastern’s Class 395 Javelin Train Sets Are To Receive A £27 million Facelift.

Southeastern Have Both 75 and 100 mph Trains

In addition to their Class 395 trains, Southeastern have the following trains in their fleet.


  1. Running a mixed fleet of 75 and 100 mph trains can’t be very efficient.
  2. The Class 465 and 466 trains are the oldest trains and date from 1991-1994.
  3. They are often to be seen in ten-car formations of 2 x 465 trains and a Class 466 train.
  4. Another twelve Class 707 trains are planned to join Southeastern.

I would expect the Class 465 and Class 466 trains to be replaced first.

What Length Will The New Trains Be?

If you look at the new suburban electric trains, they have the following lengths.


  1. Southeastern already run five-car trains as pairs.
  2. A significant proportion of existing suburban trains are five-car trains.
  3. Great Western, Hull Trains, LNER, Lumo and TransPennine Express run five-car Hitachi trains, with more companies  to follow.
  4. A pair of five-car trains make a pair of a convenient length for most platforms.

I would be fairly confident, that the new trains will be five-car trains, with the ability to run as pairs.

What Will Be The Operating Speed Of The New Trains?

To match the speed of the Class 375 and Class 707 trains, I would expect them to be 100 mph trains.

The Quietness Of Battery-Electric Trains

All of the battery-electric trains I have ridden, have been mouse-quiet, with none of the clunking you get for a lot of electric trains.

This is said in the bidstats article says this about the interiors

Interiors suitable for metro & mainline operation.

I wouldn’t be surprised to see a lot of these trains on commuter routes to attract passengers.

Battery Power

This is said in the bidstats article about battery power.

Inclusion of options for traction batteries with capability for operation in depots and sidings without the need for external power supply, and with the capability to operate on the main line where power supply is not available due to isolations or incidents, or for non-electrified line sections of up to 20 miles.

Although Merseyrail’s new Class 777 trains are not in service yet, I find it interesting that the proposed Southeastern trains will be similarly-fitted with a small battery for depot and siding operation.

The twenty mile battery range is specific and I wonder if it will be used innovatively. I suspect it could be a bit longer in the future, as battery technology improves.

Possible Electrified Routes Using Battery Power

These are a few possibilities.

The Hoo Branch

In Effort To Contain Costs For Hoo Reopening, I discussed running electric trains to a proposed Hoo station.

I made these two points.

  • Hoo junction to Hoo station is no more than five or six miles.
  • There are also half-a-dozen level crossings on the route, which I doubt the anti-third rail brigade would not want to be electrified.

It would appear that a battery-electric train with a range of twenty miles would handle this route easily.

  • Charging would be on the nearly thirty miles between Hoo junction and Charing Cross station.
  • No charging would be needed at Hoo station.

There may be other possibilities for new routes locally to open up new housing developments.

The Sheerness Line

The Sheerness Line has the following characteristics.

  • It is double-track
  • It is electrified
  • It is less than eight miles long.
  • For most of the day, the service is one train per hour (tph)
  • There are two tph in the Peak.
  • Would two tph attract more passengers to the line?
  • Does the power supply on the Sheerness Line limit the size and power of trains that can be run on the line?
  • Is there a need for one train per day to London in the morning and a return in the evening?
  • Could the Sheerness Line be run more economically with battery trains. providing a two tph service all day?

The Isle of Sheppey needs levelling up, perhaps 100 mph trains to London using battery power on the Sheerness Line, might just make a difference.

The Medway Valley Line

The Medway Valley Line has the following characteristics.

  • It is double-track
  • It is electrified
  • It is less than twenty-six and a half miles long.
  • For most of the day, the service is two tph.
  • In the Peak there are HighSpeed services between Maidstone West and St.Pancras International stations.

If electrification was removed between Paddock Wood and Maidstone West stations, the HighSpeed services could still be run and battery-electric trains with a twenty mile range could still run the Tonbridge and Strood service.

The Marshlink Line

The Marshlink Line has the following characteristics.

  • It is mainly single-track with a passing loop at Rye station.
  • It is not electrified
  • It is 25.4 miles between the electrified Ashford International and Ore stations.
  • Services are irregular and less than one tph.

If the proposed battery-electric train had a range of thirty miles, it should be able to handle the Marshlink Line.

The service between Eastbourne and Ashford International stations would need to be moved between the Southern and Southeastern operations.

The Uckfield Branch

The Uckfield Branch has the following characteristics.

  • It is a mixture of single- and double-track.
  • It is not electrified South of Hurst Green Junction.
  • It is 24.7 miles between the electrified Hurst Green Junction and Uckfield station
  • Services are one tph.

If the proposed battery-electric train had a range of thirty-miles, it should be able to handle the Uckfield Branch, with a charging system at Uckfield station.

Will Battery-Electric Trains Allow Some Lines To Have Their Electrification Removed?

There are several reasons, why electrification might be removed.

  1. It is on a line, where the electrification needs upgrading.
  2. It is on a line, where there are lots of trespassers.
  3. Possibly at a level-crossing or a stretch of track with several.
  4. Possibly in a tunnel, with a large inflow if water.
  5. It is a depot or siding, where safety is important to protect the workforce.

Obviously, the electrification would not be removed unless  battery-electric trains can handle all possible services.

These are surely some possibilities for electrification removal.

The Hayes Line

The Hayes Line has the following characteristics.

  • It is double-track
  • It is electrified
  • It is less than eight miles to Ladywell Junction, where the branch joins the main line at Lewisham.
  • It is currently run by Class 465 and Class 466 trains, which will likely be changed for the new trains with a battery capability.
  • Services are four tph.

If the proposed battery-electric train had a range of twenty-miles, it would be able to handle the route between Ladywell junction and Hayes station.

Erith Loop, Crayford Spur and Slade Green Depot

This map from shows the Erith Loop, the Crayford Spur and the Slade Green Depot.



Not many trains take the Erith Loop or the Crayford Spur.

  • The distance between Slade Green and Barnehurst is less than a mile-and-a-half.
  • Dartford station is off the South-East corner of the map.
  • The distance between Barnehurst and Dartford is less than three miles.
  • The distance between Slade Green and Crayford is less than two miles-and-a-half.
  • The distance between Crayford and Dartford is less than two miles.
  • The main line through Slade Green would need to remain electrified, as electric freight trains use the line.

I suspect, that quite a lot of electrification could be removed here, much to the disgust of the copper thieves.

It might even be possible to build on top of the depot.



November 14, 2022 - Posted by | Transport/Travel | , , , , , , , , , , , , , , , , ,


  1. Eventually, I can see batteries replacing much of the 3rd-rail electrification on suburban services. There was talk a few years back of replacing it with OLE. OLE would make sense for main lines with limited-stop services and for long-distance freight (e.g. Southampton), but otherwise would be too costly. First though, batteries have to prove themselves ‘in the field’. As you say, use in depots and other short stretches would be the obvious place to start.

    I’m not sure that high speed is all that important for stopping suburban services. Acceleration is surely more important for those.

    Comment by Peter Robins | November 15, 2022 | Reply

  2. You made me smile about tunnels and large inflows of water; they have to pump out at least 50 million litres of water from the Severn Tunnel each day.
    I imagine Southern will address their need for Electric Battery but apart from the Bromley North to Grove Park Shuttle I think you rightly identified the potential Southeastern routes.
    Having spent time on LUL depots and having an over-heightened respect of electrified tracks I think that it would be great to get rid of them on train maintenance sites.
    Like Peter I really don’t think that high speed is at all necessary for stopping suburban services. Within the constraints of passenger comfort and rail adhesion, acceleration and braking rates are far more important.

    Comment by fammorris | November 15, 2022 | Reply

    • Have you seen the news today about Echion Technologies and a grant for self charging trains. This could be spectacular and explains a lot of recent battery-electric stories.

      Comment by AnonW | November 16, 2022 | Reply

      • Yes one of the more obscure press releases I’ve ever come across, it left me scratching my head as to what it really meant.
        Looking around it seems that not only is it self-charging (I don’t really get that concept) but it charges directly from the OHL.
        Apparently they were awarded £60,000
        I’m now better acquainted with Echion Technologies who have been pioneering super fast charging batteries with Niobium based anodes and high energy density. They are working with a UK subsidiary of Allison Transmissions on e-drives

        Comment by fammorris | November 16, 2022

      • Allison’s aero-engine business is now part of Rolls-Royce. I wouldn’t be surprised to see a connection there , as Rolls-Royce make their own batteries.

        Comment by AnonW | November 16, 2022

      • Allison was sold to General Motors, I think, sometime in the late 1930s primarily as an engine business and after WW2 a Transmissions Division was set up as Detroit Diesel Allison owing to opportunities to develop the business by the American Government. General Motors sold it about 15 years ago and it finally became a public company about 10 years ago. It’s the largest manufacturer of automatic transmissions for medium and heavy duty vehicles in the world.
        The engine business was sold off to Rolls-Royce in the mid 90s as I recall.
        So no connection I’m afraid.

        Comment by fammorris | November 16, 2022

      • Are you referring to ? Charging batteries from OLE is hardly ground-breaking (I see Hitachi is now claiming over 100km for their battery trains). And Echion are not alone in developing improved batteries that can be charged more quickly. Massive amounts of money are going into that atm.

        Looks like another Highview to me – lots of hype around a product which may indeed ‘revolutionise’ something or other, but which is nowhere near large-scale production. Government ministers should get out more and look at other countries that have been running battery-powered trains for some time.

        Comment by Peter Robins | November 16, 2022

  3. Peter, oh how I remember the Maxwell Automatic Bus Transmission and the Ferodo Retarder of the 1980s being touted as the Great British riposte to all those Continental and US automotive products.
    A flatmate of mine ended up as the Technology Director of Torotrack Transmissions, which was spun off from British Leyland. This was another one of those Great British Hopes.
    Don’t see anything about them now.
    The British political class doesn’t understand industry.

    Comment by fammorris | November 16, 2022 | Reply

    • and sadly Britishvolt seems closer to collapse according to today’s headlines. A shame for the good citizens of that part of Northumberland.

      Comment by Peter Robins | November 16, 2022 | Reply

    • Reading Echion’s press releases, it appears that if you use their anodes, you get faster charging and more capacity and some battery makers have signed up. So it might be that some companies like Hyperdrive Information, who make Hitachi’s batteries will use it.

      I am reminded of this story from Liverpool University.

      Progress Is A Lot Of Small Steps

      By replacing one chemical with another, costs are cut in solar panel manufacture.

      Comment by AnonW | November 16, 2022 | Reply

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