 In 1946, given the contemporary discontent and industrial action in the coalfields following World War II, it was decided to convert seventy of the class to oil burners.The 55 class was chosen as unlike the other two sub-divisions of the Standard Goods engines their absence of eccentrics for any inside valve gear immediately adjacent to the firebox throatplate gave adequate room for the installation of the new equipment, specifically the burner and its piping at the firebox and ashpan.The tenders were fitted with a fuel tank.