China Railways JF2

A Mikani class locomotive in service with Mantetsu, with a Ta6 class coal hopper behind it.

To fill the need for powerful locomotives to haul heavy goods trains from the Fushun Coal Mines and Dalian, Mantetsu ordered the first five Mikani class locomotives from the American Locomotive Company of Schenectady, New York in 1924. After completion of the superheated three-cylinder locomotives,[1] extensive performance tests were conducted, the results of which attracted considerable attention from the railway industry; despite a wheel diameter of only 1,370 mm (54 in), they reached a maximum speed of 101.4 km/h (63.0 mph).[2] They were immediately successful, and production of copies began at Mantetsu's Shahekou Works in 1926. They were the first Mantetsu locomotives to weigh over 100 t (98 long tons; 110 short tons), as well as the first to be built with automatic stokers. Although their performance was excellent, the complexity of the three-cylinder arrangement led to consideration of a superheated 2-10-2 tender locomotive design as a replacement. However, this plan was abandoned, and more Mikanis were built instead. After a number of incidents involving broken crankshafts, the Mikashi class was designed as the successor to the class in 1933.[3]

JF2-2525 at the Shenyang Steam Locomotive Museum.

At the end of the Pacific War, the 41 Mikani class locomotives were divided between the Dalian (35) and the Fengtian (6) depots, and all were taken over by the Republic of China Railway. Following the establishment of the People's Republic and the subsequent creation of the current China Railway, they became class ㄇㄎ貳 (MK2) in 1951, and class 解放2 (JF2, jiěfàng, "liberation") in 1959. Numbered in the 2501–2550 range, they were assigned to the Wafangdian locomotive depot in Dalian and used primarily on heavy goods trains. JF2 2525 is preserved at the Shenyang Steam Locomotive Museum.