No. 245 at London Waterloo in October 1988. ©P L Chadwick
Dugald Drummond designed the M7 0-4-4T class for use on the intensive London network of the London & South Western Railway, and they performed well in such tasks. Because of their utility, 105 were built and the class went through several major modifications over five production batches, resulting in detail variations between class members such as frame length. Many of the class were fitted with push-pull operation gear to enable them to work efficiently on branch lines without having to change ends. The M7s proved to be reliable suburban passenger locomotives and as they were displaced with newer standardised locomotives, they still found work as reliable branch line locomotives. The vast majority were kept in service with British Railways until 1957 where they were gradually phased out until 1965.
(Information provided by Wikipedia)