Rail operators hope to save 2,000 tonnes of carbon a year

SOUTHERN and Southeastern have become the first train operators in the country to introduce regenerative braking via the systems third rail.

They say it will save enough electricity to power a small town, reducing carbone emissions by more than 2,500 tonnes a year.

Both companies are operated by Govia, the partnership between the Go-Ahead Group and Keolis.

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After two years of planning and testing, the first trains are now returning electricity back into the rail system when they brake, allowing other trains to draw on that energy for power.

Until now, energy released by trains during braking has been wasted in heating the resistance grids which are located underneath the trains.

Now any other train in close proximity to the regenerating train will benefit from the electricity transferred back to the third rail.

Southern's engineering director, Gerry McFadden said: "This has never been done before on the country's third rail system and we are delighted that our trains can now begin to help in delivering a greener and more sustainable railway system.

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"Both Southern and Southeastern plan to implement a phased programme which will deliver regenerative braking to the rest of the Class 377, 375 and 376 fleets."

Keith Ludeman, chairman and chief executive of Govia said: "I am delighted that Govia is leading the way in the introduction of DC regenerative braking in UK rail. Southern and Southeastern's success in this area is an excellent example of the industry working together effectively to reduce rail's carbon footprint and deliver genuine innovation."

The 750volt third rail or conductor rail is the system by which some trains draw their power. It is located alongside the running rails.

One three-car Electrostar train can put enough power back into the system per year to save around 14 tonnes of carbon.

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The introduction of regenerative braking is estimated to save enough electricity to power a small town, saving over 2,500 tonnes of carbon per year.

The implementation of this change marks the end of a 15 month project, which has been not only technically challenging, but has had many logistical issues associated with it.

Southern and Southeastern bought in technical and management expertise from Booz Allen Hamilton, one of the world's leading strategy and technology consulting firms.

The project team worked closely with trom manufacturer Bombardier, Network Rail and safety approval bodies to develop a design solution.

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The principal technical challenge was to ensure that significant levels of energy were regenerated without impacting the ability of Network Rail's power supply system to work reliably and to detect faults. This was resolved through the joint design of train protection settings, detailed modelling of the behaviour of electrical sections on the Southern network, and the completion of a comprehensive infrastructure testing programme.

Final development of the design took place on the Dorking to Horsham branch line during January and February this year.

The logistics associated with establishing the testing conditions and getting sufficient trains into the test site to absorb the regenerated energy without significantly impacting the provision of the train service was a major challenge for the project team.

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