Mountain (locomotive)
Steam locomotives with the wheel arrangement 2'D1 'are referred to as mountain , i.e. with a leading bogie , four coupling axles and a trailing axle.
history
Where high speeds were not so important, this design was a more powerful alternative to the triple-coupled Pacific early on . The first locomotive of this type built from the outset as a 2'D1 was built in New Zealand in 1908 ( class X ), two years earlier in South Africa six 2'D machines had already been retrofitted with a trailing axle to improve the running characteristics (see NGR Hendrie B ) .
Mountain locomotives were first used on mountainous routes. Only in countries where no very high speeds were driven anyway, such as B. in South Africa and other African countries with narrow gauge networks, the Mountain could, however, be a replacement for the Pacific, otherwise the Mountains outside Europe were mostly freight locomotives.
European Mountains such as the series 241 A and 5-241 A of the SNCF , one of which remained with the Deutsche Reichsbahn after the Second World War as DR 08 1001 , as well as the series 486.0 of the ČSD , were often used in heavy express train traffic in the Usually on routes on which a Pacific would have been overwhelmed due to the routing or the train weights.
In Europe, mountains were rather rare compared to America or Africa. The class 08 was the only locomotive of its kind ever used in Germany, and there were no such locomotives in Great Britain - with the exception of two mountains on the Romney, Hythe and Dymchurch Railway - nor in Switzerland or Austria.
Apart from France, this design was widespread in Spain and Czechoslovakia. Smaller series were used with the PKP series Pu29 in Poland and the BDŽ series 03 in Bulgaria.
In Africa, however, mountains were widespread, especially in South Africa they were by far the most numerous types. With 255 units of the class 15F , more units were built than any other African locomotive, and the 136 units of class 23 , with a coupling wheel diameter of 1,600 mm and a total weight of 222 t, were among the largest rigid-framed narrow-gauge locomotives ever.
Double Mountain
In Garratt locomotives the wheel arrangement (2'D1 ') (1'D2') was widespread. Because these are basically two mountain locomotives that are fed from a common boiler, these locomotives are also known as double mountain .