Southern & Southeastern
“U.K. train operators Southern and Southeastern have become the first train operators in the country to introduce regenerative braking on the third rail DC network. This groundbreaking system harnesses the energy produced during braking, transferring it back into the rail system, allowing other trains to use it.
The result is a saving of about 15% of consumption on Southern’s largest fleet of trains – and a reduction in carbon emissions by more than 11,000 tonnes a year. In recognition of this pioneering engineering feat Southern was awarded the Environmental Innovation Award at the HSBC Rail Awards.
Southern and Southeastern are both operated by Govia, the partnership between the Go-Ahead Group and Keolis. After almost two years of planning and testing, the first Class 375, 377 and 376 Electrostar trains are now returning electricity back into the rail system when braking, allowing other trains to draw on that energy for power.
Until now, energy released by trains during braking has been wasted in heating the braking resistors on the train. Now any other train in close proximity will benefit from the electricity transferred back to the third rail.
Southern’s Engineering Director, Gerry McFadden said: “This represents the culmination of an intensive 18 month project delivered in a model cross-industry partnership between Southern, Southeastern, Network Rail, and train manufacturer Bombardier, with project management from Booz Allen.” He added: “We also owe a debt of gratitude to the DfT and ATOC who have been instrumental in preparing the industry to take on the green agenda.”
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.” One three-car Electrostar train can put enough power back into the system per year to save around 14 tonnes of carbon.
Overview of the Project
All companies have a responsibility to work to alleviate climate change, and responsibility is central to public transport companies. Southern and Southeastern take this responsibility very seriously, and reducing the carbon footprint of our trains is one way to help.
With regenerative braking electricity is generated by braking trains and transferred to other trains in the area. The introduction of regenerative braking onto their fleet of Electrostar trains 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. To deliver the project Southern and Southeastern bought in technical and management expertise from Booz Allen Hamilton, one of the world’s leading strategy and technology consulting firms.
Collaboration
The project team worked closely with Bombardier (the train manufacturer), Network Rail and the various safety approval bodies to develop a design solution that would not impact the safe and reliable operation of the railway. 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 2008. 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.”
