After successful trials, Colas Rail UK will be adding a conditioner to the fuel of its diesel locomotives that has been proven to reduce consumption and cut emissions.

Colas evaluated Sulnox Eco™ Fuel Conditioner between October and December 2024 in four tampers based at Rugby in Warwickshire and Class 66 and Class 37 diesel locomotives used on Rail Head Treatment Trains based at York.

Sulnox Eco™ is a patented, 100% organic biodegradable fuel conditioner that requires no modifications to the host engines and can be added to any liquid hydrocarbon fuel.

It provides better lubrication and added detergency benefits, resulting in reduced fuel consumption and lower emissions.

Comparative tests of before and after using the fuel conditioner showed:

• 4.5% improvement. In fuel efficiency.
• 63.2% reduction in Carbon Monoxide (CO) emissions.
• 47.5% reduction in Sulphur Oxide (SOx) emissions.
• Significant reductions in particulate matter (PM), including 32.6% less PM2.5 and 30.4% less PM10.

After assessing these significant results, Colas Rail UK plans to roll out Sulnox Eco™ to the rest of its locomotive and tamper fleet over the next two years. It will also encourage its supply chain partners to follow its example in a drive to further reduce Scope 3 emissions across the rail industry.

“Cutting emissions is vital for rail’s future. These trials prove that Sulnox Eco delivers significant reductions while improving fuel efficiency. It’s a seamless, high-impact solution that helps our locomotives and on track machines burn fuel more effectively, run cleaner, and generate substantial cost savings..”

Dan Ditri, Head of Energy & Carbon at Colas Rail UK

Once all locomotives in the Colas fleet are using the new fuel condition, Colas Rail UK estimates that a 4.5% improvement in fuel efficiency will produce a six-figure annual saving on fuel costs. Along with significant reductions in emissions and cleaner engine performance, results, there is a sound basis that the conditioner will deliver a strong return on investment.

Colas Rail UK has also carried out other trials to decarbonise locomotive operations, including using solid oxide fuel cells (SOFC) running on Bio Liquefied Petroleum Gas (Bio-LPG) that has near net-zero carbon emissions to generate power for auxiliary loads.

The company has also entered a partnership with Avena Group to recycle Personal Protective Equipment (PPE) instead of it being sent for incineration or to landfill.

“We are pleased to be working with a prestigious rail industry partner as both the operating companies and their infrastructure resource capability step up decarbonisation initiatives. Sulnox is committed to being part of the solution for the rail industry, helping to reduce emissions significantly, while delivering fuel cost savings and supporting participants to meet ESG goals.”

Sulnox CEO Ben Richardson