The LNER Class V2 steam locomotives were designed by Sir Nigel Gresley for express mixed traffic work and were built between 1936-1944. The V2s were the only significant class of 2-6-2 tender locomotives used in Britain. 184 locomotives were built at Doncaster and Darlington Works, construction continuing through the Second World War as they proved their usefulness. The V2 was developed from the Class A1/A3 Pacifics with smaller driving wheels and a shortened boiler. During WW2, the V2 locomotives achieved fantastic performances of haulage. Trains of over 20 carriages loaded to 700 tons proved within their abilities. The most famous locomotive of the class is 'Green Arrow' 4771 (later 800 and 60800). 'Green Arrow' was the first of the class named for publicity purposes for the launch of the LNER's express freight services and is the only preserved example, part of the National Collection.