The Anonymous Widower

Uckfield Third Rail Is NR Priority

The title of this post, is the same as that of an article in the April 2022 Edition of Modern Railways.

This is the first two paragraphs.

Electrification of the line between Hurst Green and Uckfield in East Sussex and the remodelling of East Croydon are the top Network Rail investment priorities south of the river, according to Southern Region Managing Director John Halsall. He told Modern Railways that third rail is now the preferred option for the Uckfield Line, as it would allow the route to use the pool of third-rail EMUs in the area. This is in preference to the plan involving overhead electrification and use of dual-voltage units put forward by then-Network Rail director Chris Gibb in his 2017 report (p66, September 2017 issue).

NR has put forward options for mitigating the safety risk involved with the third-rail system, including switching off the power in station areas when no trains are present and section isolation systems to protect track workers.

The Office of Road and Rail hasn’t given Network Rail’s scheme the OK yet, but as an Electrical Engineer, I believe that a safe system is possible.

Making Charging Safe At Greenford

This article on Ian Visits is entitled Ex-London Underground Trains To Be Tested On The Greenford Branch Line.

The article describes how despite using London Underground’s four-rail electrification, it will be possible with the right interlocks and systems to make such a system safe.

As Vivarail’s system is to be installed, it must already agree with all the Health and Safety rules.

A Safe System On The Uckfield Branch


  • The unelectrified section of the Uckfield Branch is twenty-five miles long.
  • There are seven intermediate stations, with the longest section between any two stations under five miles.
  • Trains stop in each station on the route.
  • Trains appear to have a dwell time of about a minute in each station.
  • A ten-car pair of Class 707 trains would be 203.2 metres long.
  • All platforms have been lengthened for ten-car trains.
  • A battery-electric train running along unelectrified track, is no more dangerous than a diesel train.

This picture shows some typical third-rail electrification at Kidbrooke station in South East London.

Electrification At Kidbrooke Station


  1. The electrified rails are between the tracks.
  2. Gaps are possible to isolate sections of tracks.
  3. The third-rail is tapered, so that the third-rail shoes on the train can connect and disconnect easily.

Suppose you have a third-rail electric train with a range of say seven or eight miles on batteries.

Would it be possible to devise a safe electrified railway using this train and standard third-rail electrification with some safety modifications?

  • The track in each station would be electrified in the normal way with the third-rail away from the platform.
  • The length of electrification in each station would be  a few metres shorter than the length of the ten-car pair of Class 707 trains.
  • This would mean that the train would completely cover the electrification, when it stopped in the station.
  • The third-rail electrification would only be switched on, when a train is stopped in the station and the right interlocks are engaged.
  • Even if a passenger fell onto the tracks, they would probably be safe, unless they crawled through the wheels to the centre of the tracks.
  • There would be no electrification between the stations, which would protect track workers and trespassers.

I believe that a safe system can be devised.

A train going through a station would do the following.

  • Slowing down, the train would use regenerative braking, that helped to charge the batteries
  • The train would stop in a station, so that it connected with and covered the third-rail.
  • When the charging system recognised that a train was connected, it would start to charge the batteries.
  • When all passengers had unloaded and loaded and the train was ready, the driver would stop the charging process.
  • The train would move to the next station on battery power.
  • Safety interlocks would stop the charging under various unsafe circumstances.

I believe that Siemens could have developed a charging system like this for their Class 707 trains, as some of their other trains of a similar vintage to the Class 707 trains already offer battery options.

A Stepping Stone Approach

On the unelectrified section between Hurst Green Junction and Uckfield, there are the following stations.

  • Edenbridge Town – two platforms
  • Hever – two platforms
  • Cowden – single bi-directional platform – 7.9 miles South of Hurst Green Junction.
  • Ashurst – two platforms
  • Eridge – single bi-directional platform – 6.3 miles South of Cowden
  • Crowborough – two platforms
  • Buxted – single bi-directional platform – 4.7 miles South of Eridge
  • Uckfield – single platform – 2.3 miles South of Buxted

Suppose the following were to be done.

  • Do nothing at the two platform stations.
  • Fit an intelligent fast charging system at Cowden, Eridge, Buxted and Uckfield.
  • If it was felt to be needed to ensure reliable operation, the power supply to the Southbound platform could be boosted at Hurst Green station.
  • Procure some ten-car battery-electric trains, which have regenerative braking and a range of perhaps ten-twelve miles on battery power.


  1. A pair of five-car trains could be used instead of ten-car trains.
  2. Some five-car Class 377 trains fitted with batteries might be ideal.
  3. This would mean only four platforms would need to be electrified with fast charging systems.

I am sure that Vivarail Fast Charge systems could be used, if they were modified to work with standard third-rail systems and for bi-directional use.

What size of battery would be needed for this approach?

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch, which is not very challenging.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

So for a ten-car train running for twelve miles, the train would need a battery capacity of between 360 and 600 kWh.

Or if it was two five-car trains between 180 and 300 kWh in each train.

Note that Vivarail find space for 424 kWh in the two-car Class 230 train, I wrote about in Battery Class 230 Train Demonstration At Bo’ness And Kinneil Railway.

I believe that a five-car Class 377 or 707 train could be fitted with a 300 kWh battery and this would give the train a range of 12 miles, which would enable it to provide a battery-electric service on the Uckfield Branch.

May 2, 2022 - Posted by | Transport/Travel | , , , , ,


  1. It’s about time Network Rail are going to move forward with this. It’s been long overdue. Really not sure what Chris Gibb’s medication was when he thought 25kv was the solution. It clearly wasn’t. But also illogical were the rules for not extending 3rd rail beyond….. a 3rd rail environment. Following on from this, the Ashford – Rye line should be sorted. Really not sure why NR wants to prioritise the line from Wokingham to the Ash area and the North Downs line given that that route will soon see Tri-mode 769’s on it. But it would also offer a lot more flexibility for EMU’s to work the route too with additional route options and finally transfer that route to SWR.

    Comment by Andrew Bruton | May 3, 2022 | Reply

  2. It does seem that the 707s are a better train to convert, as I suspect Siemens standard train design includes battery operation.

    It could certainly be used between Ashford and Rye. The only thing, that needs to be sorted is that thirty battery electric 707s will be enough.

    It’s only building on the technology that has been stated will be used at West Ealing.

    I suspect the technology could be used on Merseyrail too!

    Comment by AnonW | May 3, 2022 | Reply

  3. RSSB have a research project “DECARB: 21st Century DC electrification infill (T1214)” which is addressing the safety issues of whether a case can be made for extending 3rd rail. It was due to have completed at end of 2021 but is still ongoing according RSSB research page.

    Comment by Nicholas Lewis | May 3, 2022 | Reply

  4. […] Uckfield Third Rail Is NR Priority, I discussed ways that the Uckfield Branch could be […]

    Pingback by Eridge Station – 3rd May 2022 « The Anonymous Widower | May 3, 2022 | Reply

  5. ORR’s fixation with the comparative risk between Fatalities and Weighted Injuries as expressed back in 2012 and more recently as connected with RSSB’s T1214 all rather overlook the sites at most danger
    More effort should be expended on protecting stations and areas like that illustrated above, after all most of the recorded Weighted Injuries on third rail occur in these areas. By comparison you are less inclined to get injuries with OHLs.
    Compared to a total 8000-odd kilometres of third rail in the UK, electrification to Uckfield amounts to an additional 0.05 – 0.1%

    Comment by fammorris | May 4, 2022 | Reply

  6. Sadly the 707’s are now going to SE, but fear not, there are other units that can be used: 379’s have also been tested with batteries for starters, then 350/2’s could be another candidate (albeit these could be more useful for SWR to replace their diesel 158 & 159 units, again with short electrified sections)… Sadly some idiot has allowed scrapping of 365’s that would have been good candidates…

    Comment by Daniel Altmann | May 4, 2022 | Reply

    • I went to West Ealing today and although nothing has started there yet except site clearance, it does appear that Vivarail and the Office of Road and Rail have reached agreement on a safe system that won’t fry any rats that trespass on the railway.

      I just wonder if similar logic and technology has meant that something has been developed to charge the train at some of the stops, so that it stepping-stones, its way to Uckfield.

      I have just modified the original post and I believe that Vivarail Fast Chargers can do it.

      Comment by AnonW | May 4, 2022 | Reply

    • The 365’s would have needed a new traction package, they were first gen three phase, to have been able to cope with batteries. One would have made a perfect test bed but we seem to prefer sending the units for scrap and then double down and export the scrap metals!

      Comment by Nicholas Lewis | May 4, 2022 | Reply

  7. […] Uckfield Third Rail Is NR Priority is based on an article in the April 2022 Edition of Modern Railways, with the same name. […]

    Pingback by Is This A Plan For The Marshlink Line? « The Anonymous Widower | May 5, 2022 | Reply

  8. […] Uckfield Third Rail Is NR Priority talks about running battery-electric trains on the Uckfield Branch and the Marshlink Line. […]

    Pingback by Are Finally Battery-Electric Trains Going To Enter Service? « The Anonymous Widower | May 5, 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 )

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: