The B4 class were 4-4-0 steam locomotives for express passenger work on the London, Brighton and South Coast Railway. They were designed by R. J. Billinton and were either built at Brighton works 1899–1902 or else by Messrs Sharp, Stewart and Company in 1901. Twelve members of the class were rebuilt from 1922–1924 by L. B. Billinton with a larger boiler, cylinders and a superheater. The rebuilt locomotives were classified B4X.
The performance of Robert Billinton’s B2 class 4-4-0 locomotives of 1895–1897 had proved to be disappointing and they had not been able to replace the earlier Stroudley’s B1 class 0-4-2 on the heaviest London to Brighton express trains. Billinton therefore sought authority for the construction of twenty-five larger and more powerful 4-4-0 B4 class locomotives. The first two of these, Nos. 52 and 53, were completed at Brighton works between December 1899 and January 1900, both of which performed well and demonstrated that the new design was sound. However during the spring of 1900 a backlog of repair work at Brighton meant that the third (No. 54) was not completed until May 1900. The railway therefore approached Sharp, Stewart and Company to supply twenty-five further examples over the next twelve months. These were all delivered between June and October 1901. By 1901 Brighton had overcome the backlog of repair work and five further locomotive boilers were ordered from Sharp, Stewart and Company to be used on additional locomotives to be built at Brighton between June and September 1902.
The B4 4-4-0 was RJ Billinton's last passenger tender locomotive and had many similarities in design with his earlier ones although were much improved in the size and power departments! Externally similar, the boilers were quite a lot bigger than Bessemer's, the previous largest loco, and had 180lb per sq. in. working pressure. The first three of the class had three-ring boilers with a centreline some 8' 1˝" above rail level whilst the remainder had two-ring boilers pitched 1˝" higher. Some of the class were built at Brighton, with others that became known as Scotchmen being built by Sharp, Stewart & Co. in Glasgow. The whole class was also known unofficially as "Sirdar" after the second engine to be built. Being the largest and most powerful express locomotives to be seen on the LB&SCR they were immediately put to work on the 8:45 a.m. up business from Brighton and the 5:00pm down from London Bridge.
The B4 class successfully hauled the heaviest express trains on the London, Brighton and South Coast Railway until around 1912 when they were gradually replaced by the larger H1, H2, J1 and J2 classes. Thereafter they were regularly used on slower and lighter services. According to O.S. Nock the B4 class "were among the finest passenger locomotives of their day".
In 1912 No.59 was fitted with a Phoenix superheater, a rather large piece of apparatus that required much modification of the engine. A vast extended smokebox was fitted and the frames were modified to the extent that all the elegant curves were lost, being replaced by angle irons and an upward curve at each end. The experiment was not a success (as various other railways also discovered) and did not last long. Then, in 1935, the Southern Railway combined parts of No.59 (including the modified frames) with parts of No.68 to form composite engine No.2068.
Some examples were named after events and people involved in the Boer War whilst two, No.42 His Majesty and No.46 Prince of Wales, were frequently used for Royal Trains, and as such kept their names after Marsh scrapped nearly all of them until finally seeing them removed by the Southern Railway. Empress and Sirdar claimed a place in the history books when they worked Queen Victoria's funeral train which, on being taken over from the L&SWR at Fareham running late, arrived at Victoria some two minutes early. Empress was the train engine whilst Sirdar was the pilot engine running ahead of the funeral train.
No.52 Siemens was, briefly, renumbered 50 by mistake in 1905 and in 1908 was re-named Sussex (the name of No.72) due, it is believed, to an error in the paint shop! In addition to the two locos mentioned above, Richmond, Sussex (No.72), Princess Royal, Norfolk, Billinton (was Balmoral) and Devonshire kept their names until Southern Railway days.
No.74 was withdrawn during 1935 by the Southern Railway, but was returned to traffic in 1937 and subsequently passed into British Railways' stock in 1948. No.47, No.50 and No.60 were fitted with extended smokeboxes in 1915, No.44 was rebuilt with a superheater in 1922, No.45 was originally fitted with a Drummond water-tube firebox which was removed in 1911 and No.46 was rebuilt with larger cylinders and extended smokebox in 1918.
In 1922 Lawson Billinton started the rebuilding of twelve of the B4 class into class B4x.
Between 1923 and 1928 SR numbers were the LBSC numbers with the added prefix 'B'
At the outbreak of the Second World War two of the surviving eight, Nos. 2051 and 2068, were loaned to the LNER. The two engines returned to the Southern Railway in 1944.
The first loco withdrawn by BR was 32044 in September 1948 from Eastbourne shed.
The last four locos withdrawn were 32054, 32062, 32063 and 32068 in May 1951, all from Eastbourne shed.
None are preserved.
Designer : R. J. Billinton
Builder : Brighton Works 42–46, 52–54 : Sharp, Stewart & Co. 47–51, 55–74
Build date : 1899–1902
Total produced : 33
Configuration : 4-4-0
Gauge : 4 ft 8 1/2 in (1,435 mm)
Leading wheel diameter : 3 ft 6 in (1.067 m)
Driver wheel diameter : 6 ft 9 in (2.057 m)
Locomotive & tender combined weight : 86 long tons 15 cwt
Loco weight : 51 tons 10 cwt
Tender weight : 35 tons 5 cwt
Fuel type : Coal
Boiler pressure : 180 psi (1.24 MPa)
Cylinders : Two (inside)
Cylinder size : 19 in × 26 in (483 mm × 660 mm)
Valve Gear : Stephenson (slide valves)
Tractive effort : 17,730 lbf (78.9 kN)