After extensive static testing of a class 67 at Nottingham, DB Cargo UK have been given clearance by Network Rail to test a class 66 locomotive fuelled with pure renewable Hydro-treated Vegetable Oil (HVO). The experimental fuel is compatible with the diesel engine, and is part of the company’s decarbonisation strategy. The test, under revenue-earning conditions, took place last week and has been heralded as a complete success by the company.