Member News

Chiltern Railways brings brand new type of climate friendly and pollution cutting train into service

10 February 2022 | Porterbrook

Chiltern Railways has this week (w/c 7 February) launched an innovative type of train that significantly cuts CO2 emissions, saves fuel and reduces noise and air pollution.

The train known as 'HybridFLEX’ has entered service between Aylesbury and London. 

Chiltern Railways, Porterbrook (the train owner) and industrial technology company Rolls-Royce have worked together to convert a diesel train into one that now runs on both diesel and battery power.

The concept train is the first 100mph capable battery-diesel hybrid train to operate on the UK’s national rail network.

The train has been retrofitted with a Roll-Royce powerpack which means quieter and quicker journeys and a 25 percent reduction in CO2 emissions on every journey. Nitrogen oxide and pollutants are also cut by 70 and 90 per cent respectively.

The HybridFLEX train substantially cuts fuel usage and reduces noise by up to 75 per cent in and around stations and urban areas. It also presents the opportunity for quicker customer journeys in the future.

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.”

The HybridFLEX train will initially operate between Aylesbury and London Marylebone with plans to bring the new type of train to the London to Oxford via Bicester Village route in the coming months.

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.”

Rolls-Royce’s ‘mtu‘ Hybrid PowerPack pairs a diesel engine with an electric unit that can function both as a motor and as a generator. The battery system stores power that is recovered during train braking. 

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.”

Notes to Editors
  1. HybridFLEX picture: l-r Helen Simpson (Innovation and Projects Director, Porterbrook), David Eaton (Director, Rolls Royce Solutions), Bruce Phillips (Managing Director Rolls Royce Solutions), Richard Allan (Managing Director Chiltern Railways),  Lei Berners-Wu (Vice President Global Industrial Business at Rolls-Royce Power Systems)

Media Contacts

Porterbrook Leasing
James McGowan, Director of Corporate Affairs, or +44 (0)7932 749095

Financial or corporate PR enquiries can also be directed to:

Portland Communications

Simon Evans, Partner - 

Richard Brooks, Consultant - or +44 (0)7740 858477

About Porterbrook

• Porterbrook owns almost a quarter of the national passenger rail fleet and currently has around 4,000 vehicles on lease or on order. To date we have invested £3bn in new passenger and freight vehicles and are actively looking to invest a further £1bn in UK rail over the coming years
• Engineering excellence is central to our role as a leading railway asset owner and manager. Porterbrook is a delivery partner, supporting improved industry performance and reliability across operations. Our 30 to 35-year whole life asset management approach optimises value to passengers & taxpayers and aims to minimise environmental impact
• We have an established reputation for delivering new technologies, such as battery, hybrid and hydrogen powered trains. These innovations support the government’s commitment to Net Zero by 2050 ambitions, improve air quality, reduce emissions, and enhance network resilience
• In 2020 we introduced HydroFLEX, the UK’s first hydrogen-powered train, in partnership with the University of Birmingham. This innovative train will be showcased at Glasgow in November during COP26
• In collaboration with our industry partners, we project manage the delivery of regular upgrades to our rolling stock fleets. Each year we invest over £150m in our existing assets, supporting nearly 100 UK-based companies and supporting c.7,000 jobs
• Porterbrook employs over 180 people, of which three quarters are engineers and project managers. In addition, 32% of Porterbrook’s workforce is female including a number of our executive team which compares favourably to the UK rail industry average of 16%
• In October 2014, the Porterbrook Group of companies was acquired by a consortium of investors including Alberta Investment Management Corporation (“AIMCo”), Allianz Capital Partners (“ACP”) on behalf of certain insurance companies of the Allianz Group, EDF Invest and a consortium of Utilities Trust of Australia (“UTA”), The Infrastructure Fund (“TIF”) and Royal Bank of Scotland Group Pension Fund (“RBS”) 

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