Battery-powered train enters service

After a gap of more than 50 years, battery-powered train technology has returned to Britain’s rail network.

Between now and the middle of February the new vehicle, known as the Independently Powered Electric Multiple Unit (IPEMU), will run in a weekday timetable service between Harwich International and Manningtree stations in Essex. 


Jointly developed by industry partners including train manufacturer Bombardier, train operating company Abellio Greater Anglia, and Network Rail the vehicle is effectively a modified version of the 379 Electrostar, the train type currently being used on a number of routes including the Stanstead Express.

As previously reported by The Engineer the train was adapted by Bombardier and fitted with lithium (iron magnesium) phosphate and hot sodium nickel salt batteries that underwent a series of lab tests before being fitted to the train. The train’s public debut follows trials in 2014 at test tracks in Derby and Leicestershire

According to Network Rail – which has pledged to reduce the network’s running costs by 20 per cent over the next five years – the project could ultimately lead to the development of a whole fleet of battery powered-trains that could help make Britain’s rail network quieter and more efficient. 

Any future IPEMU would most likely be designed as a new train and not an adapted unit, to minimise energy consumption, but this project will also provide useful information for retrofit.

The network operator has also claimed that the technology could be used to bridge gaps between electrified parts of the network and branch line where installing overhead electrification is considered to be too expensive.


The new vehicle is also expected to lead to a noticeable improvement in passenger comfort.  ‘Most travellers will recognise how quiet and smooth the ride is compared to a diesel-powered train’ claimed Network Rail principal engineer James Ambrose.

Battery locomotives have been used on railways for around 100 years, including in munitions factories during World War 1 to avoid the risk of explosion from sparks emitted by steam locomotives.  However widespread adoption has – until now – been held back by battery technology.