SER 235 class

History

Until 1864 the South Eastern Railway had very few tank locomotives. In that year the 205 class 0-4-2T locomotives were introduced, for use on the London suburban passenger services; they were designed by James I. Cudworth, the company's locomotive superintendent. They performed well, but their capabilities were restricted by the small fuel and water capacities; so after twelve of these were in service, Cudworth produced an enlarged version of the design. With the fuel capacity raised from 0.75 long tons (760 kg) to 1.25 long tons (1,270 kg) and the water capacity raised from 690 imperial gallons (3,100 l) to 850 imp gal (3,900 l), the extra weight and length that this required behind the cab made it necessary to support the rear of the locomotive on a bogie in place of the single rear axle, producing an 0-4-4T - the first of that wheel arrangement to be built for an English railway (the first Scottish railway to use the 0-4-4T wheel arrangement was the Caledonian, in 1873). There were compensating levers to equalise the weight between the coupled axles, and the outside-framed bogie also had compensating levers; it carried about a third of the locomotive's weight. Like the 205 class, they burned coke as a fuel.

At first, they were mainly used on the services to Greenwich. Only one batch (of seven) was built, in 1866; there were troubles with the bogie, and so when more were required, Cudworth once more used the 0-4-2T type, producing the 73 class. However, the 235 class continued to be used, and all were given new boilers between 1877 and 1883. Under Stirling's locomotive classification scheme (September 1879), they formed Class J. They were withdrawn between 1887 and 1893.