In 1899 the South Eastern and London, Chatham and Dover railways came under common management as the South Eastern & Chatham Railway. The new enlarged company appointed Harry Smith Wainwright as its' chief mechanical engineer and he set about providing new locomotives which would prove so capable as to last until the end of steam with British Railways Southern region.
The H class 0-4-4 tank engines were built originally for suburban and semi-fast services replacing the Kirtley R and R1 classes which had been a highly successful locomotives but by 1900 were proving underpowered for the increasing train loads required. The H class was a new design based heavily on the Kirtley engines, enlarged to provide increased power in the cylinders and importantly the boiler. The first locomotive, number 540 was completed at Ashford in November 1904, with six more entering service before the end of the year. The engines quickly proved to be very free steaming, providing the capacity in steaming rate and recovery for the frequent stops and quick starts required for suburban service. More H class locomotives followed quickly, building up to a total of 64 in 1909.
When Richard Maunsell was appointed to the post of chief mechanical engineer of the SE&CR in 1913 it was noticed that while 66 H class engines had been ordered only 64 had been constructed. It quickly transpired that while 66 sets of components had been produced two boilers had been fitted to R class engines. The H class boiler was proving to be an excellent steam generator and further boilers were ordered, reaching a total of around 250 boilers not only completing the 2 outstanding H class engines but also being fitted to the SECR R1 and SER Q1 0-4-4 tanks, SER O1, R1, LCDR B1 and B2 class 0-6-0 locomotives.
Surprisingly for locomotives with working lives of over 50 years there were few design differences between batches of H class locomotives and fewer visible differences until after nationalisation. Some engines were built with different coal and water capacities, though the external dimensions of the tanks and bunker were unchanged.The entire class featured the distinctive 'Pagoda' cab, intended to provide additional weather protection to the crew when they were viewing the line and signals ahead by looking along the outside of the cab. Ten locomotives were built with lower bunkers with a different top profile and lacking the flared top. It is believed this was done with thoughts of fitting these engines for pull-push service, which many H class engines were to be fitted for much later, though several of the low-bunker engines were later fitted with flared tops to the bunkers, though lacking the lower beading strip.
The H class engines worked for around 20 years on their intended suburban duties, but after the formation of the Southern Railway in 1923 and the commencement of electrification projects the engines found employment in an increasing number of roles away from suburban London. The engines were used on many secondary duties, stopping trains and services on lines which connected between the main London routes, some parcels and empty stock duties. Two of the engines were scrapped during WW2, with routine shopping being delayed the engines likely supplied their classmates with spare parts before the decision was taken not to undertake the growing list of repairs needed.
In 1949 planned withdraw of the older D3, R and R1 classes created a lack of locomotives fitted with the Southerns air controlled regulator pull-push system and the equipment was fitted to H class locomotives. The class now became increasingly associated with some of the well-known Southern branches like the Hawkhurst and Westerham lines. Many continued to work on through routes, increasingly with pull-push trains with the now preserved shed of Tunbrigde Wells West gaining a growing allocation, as the crews there disliked the ex-LSWR M7 class engines.
Withdraw of the H class engines began in 1951, though progressed slowly at first, however as British Railways continued to expand the electrified network and began to take a careful look at the economics of many minor routes the steam duties began to decline. Later introduction of diesel units on services which were to continue into the future and line closures initiated under the Beaching report saw the last H class locomotives withdrawn in January 1964.
Luckily however the locomotive of the last H class hauled service train, BR number 31263 was purchased for preservation, initially going to the Kent & East Sussex Railway at Robertsbridge. Since 1976 the locomotive has been based at the Bluebell Railway where it has been returned to service, demonstrating the unexpectedly capable performance of what appears to be a small and elderly looking tank engine.
Much information gleaned from an extensive article by I C Coleford published in Railway Bylines Annual no.1 (Irwell Press 1997)