This is the DRS 'Flatrol' atomic flask wagon and the first batches of them, totalling eight, was built at Ashford in 1976 and 1978. Two more were built at Shildon in 1982, seven at Swindon in 1986 and the main batch of 34 were built by Procor (UK) Ltd two years later. They are used to carry spent nuclear fuel in flasks from various BNFL power stations to the Sellafield reprocessing plant in Cumbria. The flask sits beneath the white hood. With various batches being made, there are design differences.