The JGR Class 3900 (originally the JGR Class AD) was a 0-6-0RT Switcher-type side tank Abt rack rail steam locomotive operated by the Japanese Government Railways from 1892 to 1922.
History[]
The Class 3900 was an early steam locomotive operated in Japan. The type was manufactured for the JGR, with four locomotives manufactured by Maschinenfabrik Esslingen in Germany and delivered in 1892. The locomotives were classified the Class AD on the JGR and numbered 194, 196, 198 and 200; the locomotives were then renumbered 126, 128, 130 and 132 to avoid confusion with the Nippon Railway, then reclassified as the Class C1 and renumbered 500 through 503. The locomotives were ordered out of necessity as the JGR had required a dedicated rack rail locomotive to scale the 66.7‰ (1/15 gradient) gradients of the Usui Pass. The locomotive was also the first German locomotive ordered by the JGR. Three more locomotives were ordered from Esslingen in 1908, numbered 518 through 520. Test runs were conducted but these did not go too well as the engineers ignored the advice of the German engineers. Older locomotives were also converted to burn oil to reduce soot levels.
The locomotives were reclassified as the Class 3900 in 1909 when a formal rule regarding standardized classification of locomotives was enacted; the locomotives were thus renumbered 3900 through 3906. These were mostly used to scale the Usui Pass, but the locomotives were rather notorious for producing too much soot from steam; these caused the crews and passengers to fall ill and sometimes even die from soot poisoning. When the section for the Usui Pass was electrified, the Class 3900s were no longer needed there and as such they were used to haul normal freight trains. The locomotives were retired in 1922. No Class 3900s survive, and these were the last Abt rack rail steam locomotives to ever operate in Japan.
The Class 3900 is the only known JGR locomotive to have been manufactured by Esslingen.