BR, Lord Nelson Class, 4-6-0, 30850 'Lord Nelson' - Era 5

In order to cope with the increasing weight of express passenger traffic on the Southern Railway following Grouping, Richard Maunsell, the Chief Mechanical Officer, needed a locomotive that was more powerful than the King Arthur class; being capable of hauling 500 ton trains at a speed of 55mph. To do this, Maunsell altered the positions of the cranks on the Lord Nelson design to give eight exhaust pulses per revolution, rather than four and the increase in power over the two cylinder design of the King Arthurs was significant, giving rise to the claim by the Southern Railway of the class being "the most powerful express locomotive in Britain", based on the theoretical tractive power.

Maunsell decided to produce one example as a prototype, E850 Lord Nelson, which was completed on August 11, 1926 and after trials at Eastleigh, it was sent to Nine Elms for trial running on the Western section mainlines to Bournemouth, Portsmouth and Exeter, before moving across to Battersea for trials on the Dover boat trains.

850 Lord Nelson entered traffic nominally allocated to Stewarts Lane and this was followed by a short spell at Exmouth Junction, from March/April 1930, as the locomotive headed up the Atlantic Coast Express. The first of the Bulleid modifications took place in January 1942, just before Lord Nelson was allocated to Bournemouth in February 1943. Renumbered to 30850 under British Railways in October 1948, in January 1949 Lord Nelson returned to Eastleigh from where it was withdrawn in August 1962. Preserved as part of the National Collection, the locomotive now resides with the Mid-Hants Railway.