In a significant stride towards sustainable rail operations, Colas Rail has completed a successful trial of employing Hydrotreated Vegetable Oil (HVO) as an alternative to diesel fuel in its locomotive 56051. The engineering support, logistics, and heavy haul specialist operator has been running the example of the class on sustainable fuel, as an alternative to diesel, in regular, revenue-earning service. The trial, which ran on a Chirk to Baglan route, showcased promising results regarding reduced carbon emissions and set an encouraging precedent for greener rail freight operations.