This month Britain’s first 100mph capable battery-diesel hybrid has been launched by Chiltern Railways.

The passenger service has been fitted with a battery that uses 20 percent less fuel, notably cutting air (70-90 percent reduction) and noise pollution (75 percent reduction), and carbon emissions (25 percent reduction).

The 20-year-old diesel train can now run solely on battery power when arriving and departing stations.

Running primarily between Aylesbury and London, the train is known as ‘HybridFLEX’ and is a result of the four year partnership between Chiltern Railways, Porterbrook and Rolls-Royce.

Retrofitted with a Rolls-Royce powerpack, the train will run quieter and quicker as well as being the first to operate on the UK’s national rail network. The powerpack pairs the diesel engine with an electric unit which performs as both a generator and a motor.

RailAdvent took a look at the HybridFlex train last year, and you can read about our special visit here

The train’s system can store power which is recovered during braking. There are also plans in the coming months to bring the train to the London to Oxford via Bicester Village route.

Richard Allan, Chiltern Railway’s Managing Director, said:
“Chiltern Railways is determined to operate a railway that is as sustainable and environmentally friendly as possible.
“We have worked hard with our partners to fit a powerful battery power pack underneath a 20-year old diesel train to make the train cleaner, quieter and quicker.
“We are really proud that this concept train is now carrying customers and look forward to assessing its performance in daily service.”

Mary Grant, CEO of Porterbrook said:
“The entry of our hybrid battery-diesel train HybridFLEX into passenger service is great news for Chiltern Railways and its customers. It’s a significant first step in demonstrating how improvements to this fleet can reduce emissions and improve air quality both at stations and other locations across the network.
“HybridFLEX is part of Porterbrook’s growing portfolio of alternative traction systems designed to help deliver a more sustainable railway.”

Warren East, Chief Executive Officer, Rolls-Royce said:
“In this critical decade of climate action, today’s entry into service of the HybridFlex train demonstrates what we can achieve through technological innovation and agile collaboration. This smart piece of engineering enables the acceleration of the UK Government ambition to remove all diesel-only trains from the network by 2040, making rail journeys quieter, cleaner and faster. We’re delighted to be part of this groundbreaking team alongside Porterbrook and Chiltern Railways and look forward to seeing the train in service.”

Rail Minister Wendy Morton said:

“Rail is getting even greener and Chiltern Railways’ launch of this cutting edge hybrid train is another major leap forward.

“We are working across transport to hit net zero by 2050 and it is brilliant to see our railways rising to the challenge.”