Three-quarter view of Colas locomotive 56051 named Survival and running on HVO fuel

Colas Rail UK Embraces Hydrotreated Vegetable Oil

Colas locomotive 56051 "Survival", running on HVO fuel Paul Conway / Colas Rail UK - LinkedIn - Facebook

In a significant step towards a greener rail industry, Colas Rail UK has recently conducted trials using hydrotreated vegetable oil (HVO) as an alternative to diesel fuel in their locomotives. This move aims to significantly reduce carbon emissions, with HVO offering a claimed 90 per cent reduction in comparison to traditional diesel fuel. They may not be the prime movers in the race to net-zero, but Colas is running with the throttle wide open to become a leader in the industry.

In the distinctive yellow and orange livery of Colas Rail UK, locomotive 56051 is leading a green liveried future for the specialist freight and engineering support operator. Named ‘Survival’, the unit has been at the forefront of trials, showcasing the potential of HVO in transforming the environmental impact of rail freight transportation. As an operator active in the furthest flung parts of the network, where traditional electrification may be a long way in the future, Colas is embracing renewable fuel sources, as they aim to contribute to a more sustainable future for the rail industry.

Towards a zero-emissions railway

As well as being a respected heavy haul and bulk freight operator, Colas Rail UK is often characterised as the go-to rail engineering solutions provider. That diverse portfolio of contracts sees the company active in some of the lesser noted locations for freight traffic. The distinctive locomotives pick up trains in places that may challenge many a geography student to locate. The likes of Blyth and Fort William may see their trains daily, but may never see enough traffic to justify wiring up, even in the current environmentally-led drive towards a zero-emissions railway. Indeed, places like Fort William in the north west of Scotland will see their passenger trains convert to hydrogen or battery, with the Scottish government in Edinburgh admitting that overhead wires are not an economic proposition.

A Colas Rail UK class 70 heavy diesel hauls a train of tanks round a tight curve outside Perth in Scotland
A Colas Rail UK reach the parts other rail freight operators rarely venture. This class 70 diesel hauls a train of tanks round a tight curve outside Perth in Scotland. Image: John Cumming.

Nevertheless, with the prospects of rail freight taking up a greater proportion of the resources generated in the remoter parts of Scotland, an alternative to diesel power is something that must be addressed by operators in that sector too. Colas locomotives have been seen at the head of heavy freight traffic, such as the recent timber train trials in Scotland and Wales. Add that to their specialist support in delivering infrastructure projects and maintenance trains, and it is not hard to see why the company is actively assessing alternative fuels that can be poured straight into the tank. The company says their commitment to innovation and environmental responsibility has made them a key player in driving sustainable practices within the industry.

Commitment to decarbonisation

Hydrotreated vegetable oil (HVO) is a renewable diesel fuel derived from vegetable oils or animal fats. It undergoes a process called hydrotreatment, which removes impurities and enhances its combustion properties. The result is a fuel that closely resembles fossil diesel but offers significant environmental advantages. HVO is a cleaner-burning fuel with lower greenhouse gas emissions, reduced particulate matter, and lower levels of nitrogen oxide (NOx) emissions.

A huge piling machine, fuelled by HVO, at work on a construction site for HS2
A huge piling machine, fuelled by HVO, at work on a construction site for HS2. That company has committed to reducing carbon emissions in the construction industry. Image HS2.

Colas Rail UK joins a growing list of operators in the rail industry who have recognised the potential of HVO in reducing their environmental impact. Rival freight operator DB Cargo UK and the infrastructure agency Network Rail have both previously utilised HVO in their operations, aligning with their sustainability goals and commitment to decarbonisation. Construction materials supplier Tarmac, a prominent rail freight customer, has also endorsed low-carbon HVO fuel on freight trains operating on the West Coast Main Line.

The HS2 company behind the mammoth high speed rail project to build a new line between London and Birmingham has also embraced this alternative fuel source in an effort to reduce emissions in the construction sector. However, the trial of HVO by Colas and other operators marks a significant shift towards greener locomotives in the UK rail industry. Despite a setback for alternative fuels (a UK passenger operator sustained some maintenance issues) the use of HVO is expected to grow, further enhancing the environmental credentials of the rail freight sector.

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Author: Simon Walton

Simon Walton is UK correspondent for and

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