Prussian G 8

The Prussian Class G 8 locomotives were eight-coupled, superheated, freight locomotives operated by the Prussian state railways. There were two variants: the G 8 built from 1902 with a 14 tonne axle load and the "reinforced G 8" (verstärkte G 8) built from 1913 (later designated the G 8.1) with a 17-tonne (17-long-ton; 19-short-ton) axle load. The latter was the most numerous German state railway (Länderbahn) locomotive, over 5,000 examples being built. A total of 1,054 Prussian G 8 locomotives were built between 1902 and 1913 by various manufacturers. It was the first superheated goods train locomotive in Prussia, which is why it initially suffered from a host of teething troubles. One further problem was the restriction to a 14-tonne (14-long-ton; 15-short-ton) axle load; as a result many components had to be made too light in order to save weight. During its period of procurement constant modifications were made to the locomotives: the cylinder bore was increased from 575 to 600 mm (22.64 to 23.62 in); and the grate area, evaporative heating area and superheater area were also increased in size. Seven engines were experimentally fitted with Stumpf parallel flow cylinders (Gleichstrom-Zylindern). Ten more were given Lenz valve gear. Neither of these variants improved on the standard design however.