LB&SCR I2 class

The LBSCR I2 class was a class of 4-4-2 steam tank locomotives designed by D. E. Marsh for suburban passenger service on the London, Brighton and South Coast Railway. The I4 class were of the same design but incorporated a superheated boiler.

I2 Class

In 1907, following the failure of his I1 class, Douglas Earle Marsh sought to remedy some of the faults with a new design of 4-4-2T with a longer wheelbase, larger boiler and detailed changes to the front end. In the original order, five of the locomotives would incorporate a superheated boiler, to be supplied by the North British Locomotive Company, and the remainder traditional saturated steam boilers from Brighton Works. In the event, the superheated boilers were delayed in construction and so all ten I2 locomotives had traditional boilers.

I4 Class

When the superheated boilers eventually arrived they were used for five further locomotives of the same design as the I2, but these were classified as I4.

Unfortunately the neither the I2 nor I4 class addressed the fundamental problems with the I1 class, which was a firebox that was far too small. As a result, the two classes had relatively short lives working lightly loaded secondary services, and the Stroudley D1 class, and Billinton D1 class, which they had been designed to replace, continued working.

London, Brighton and South Coast Railway

The London, Brighton and South Coast Railway (LB&SCR; known also as "the Brighton line", "the Brighton Railway" or the Brighton) was a railway company in the United Kingdom from 1846 to 1922. Its territory formed a rough triangle, with London at its apex, practically the whole coastline of Sussex as its base, and a large part of Surrey. It was bounded on its western side by the London and South Western Railway (L&SWR), which provided an alternative route to Portsmouth. On its eastern side the LB&SCR was bounded by the South Eastern Railway (SER) – later one component of the South Eastern and Chatham Railway (SE&CR) – which provided an alternative route to Bexhill, St Leonards-on-Sea, and Hastings. The LB&SCR had the most direct routes from London to the south coast seaside resorts of Brighton, Eastbourne, Worthing, Littlehampton and Bognor Regis, and to the ports of Newhaven and Shoreham-by-Sea. It served the inland towns/cities of Chichester, Horsham, East Grinstead and Lewes, and jointly served Croydon, Tunbridge Wells, Dorking and Guildford. At the London end was a complicated suburban and outer-suburban network of lines emanating from London Bridge and Victoria, and shared interests in two cross-London lines.