A most interesting example of one of the former G.W.R. Diesel Railcars in the shape of W 17 W ., this one not having been designed or intended for passenger carrying duties but for use as an express parcels Railcar . Built in 1936 this unit had twin A.E.C. power units giving 242 h.p. , but no seating for passengers . The contrast in the rounded front end of W17W with the passenger version on the right , with its wedge shaped front and rear ends , is clear in this view. The railcars lasted in service until the early ' sixties , with W22W being rescued from Barry yards following withdrawal in 1962 and now preserved and in working order at Didcot with the Great Western Society.