extended the design to create his D3 passenger tanks. During the 1870s Drummond built six 0-4-2 tank locomotives that were almost identical for the North British Railway after 1875. He too extended the design to produce the first of his several successful 0-4-4T designs for the North British and Caledonian Railway. Drummond's successful LSWR M7 class is also a direct descendant of the D1 class. References Sources Ahrons, E. L. (1927) The British Steam Railway Locomotive from 1825 to 1925, London Locomotive Publishing Co. Ltd. (p. 199) External links Rail UK database entry 0-4-2T locomotives D1 Neilson locomotives Railway locomotives introduced in 1873 Scrapped locomotives Standard gauge steam locomotives of Great Britain Passenger locomotives