Direct Rail Services (DRS) has a variety of Class 37s operational and others stored. DRS originally purchased and operated a mix of class 37/0s, 37/4s, 37/5s and 37/6s . Most of the DRS 37s were used on nuclear flask services coming from a host of places including Hunterston, Torness, Heysham, Hartlepool, Sizewell, Bridgwater, Valley, Dungeness, but are now being replaced by Class 68s. These are empty or full FNA wagons often containing spent nuclear fuel. Following a review of traction requirements and delivery of its new Vossloh/Stadler UK Light Class 68 diesels and Stadler UK Dual Class 88 bimodes, DRS has stored, withdrawn or sold most of its Class 37 fleet, apart from the 37/4s.