90 years ago today, the first
GWR▸ Diesel Railcar made its first run -
WikiPedia tells usThe prototype unit, No. 1, made its first run on 1 December 1933 between London Paddington and Reading with a large number of press representatives.
38 were built, of which three have survived into preservation - just one operational at present. There were the precursors of the bubble cars and then the class 153. I would argue that single carriage multiple units these days are useful as extra carriages onto other trains (or in pairs) but a diagram that works with a single carriage train is a hard one to make a case for. That view many vary on lines that support both longer distance fast services and still have a number of intermediate stations to be served.