The standard BR insulated van looked very like the standard ventilated van but did not have ventilators in the end walls. Built at Wolverton to diagram 1/251, they had planked sides and doors identical to the early vent vans. They had no external ladders nor rooftop ice boxes, as previous insulated vans had, but they were built for meat traffic and the chassis was to the same design as that of the diagram 1/250 meat van. 250 were built and, like the standard meat van, they had a short life. They were later used as ale or fish vans - although, with their short wheelbase, they were unsuitable for the fast Blue Spot fish trains