The SY class was developed by the Dalian Locomotive and Rolling Stock Co., and the primary purpose for the locomotives was usage in industrial services.[3] The basis for the SYs was the JF6 class, which was already a lighter variant of the JF1 class designed by the American Locomotive Company (ALCO), but the SYs would incorporate some newer design features introduced on other locomotives, such as the JS and RM classes.[3][4] The SY features the JF6s lacked included taller smokestacks, different front step and handrail arrangements, different motion bracket arrangements, a higher boiler pressure (210 psi (1,400 kPa), a lower axle loading (15 tonnes (33,000 lb), and all boxpok driving wheels.[3][5]
The new class was originally designated as the GN (Chinese: 工农; pinyin: Gong Nong; lit. 'Workers and Peasants'), but it was quickly changed to SY (Chinese: 上有; pinyin: Shàng Yóu; lit. 'Aim High').[3] The SY designation was possibly influenced by a quote from Chairman Mao (Chinese: 全力以赴、志存高远，在社会主义建设中取得更大、更快、更好、更省的成果。; lit. 'Go all out', 'aim high', 'and achieve greater', 'faster', 'better and more economical results in building socialism.').[3] The prototype SY (SY-0001) was constructed in 1960, by the Tangshan Locomotive and Rolling Stock Works, and thirteen others followed suit that same year.[3]
The first SYs were originally equipped with design features incorporated by the JF series, including the same horizontal cab and tender designs, stepped running boards, and disc leading wheels.[6] In 1961, the Sifang General Repair Works erected two more prototype SYs, both of which were exported to Vietnam, the following year.[7] By 1966, the SY design became finalized with some standardized changes, including a widened cab, and commercial production on the class began.[6] Tangshan would construct over 1,700 SY locomotives, but some would also be built by workshops in Jinan, Tongling, and Changchun.[1]
In service, all of the SYs were assigned to shunt and haul freight trains in numerous industrial areas throughout China, including coal mines, iron ore mines, petroleum fields, chemical plants, power stations, steel mills, and machine factories.[8][9][10] In mining areas with long-distance rail networks, the SYs would also be assigned to haul passenger trains.[3] Sometime during production, the SY class received a new tender tank design with sloped-back sides to improve rearward vision for crews, since SYs often operated in reverse, during industrial service.[11] The first locomotive to receive the new tender design was SY-0877.[11]
In July 1976, SY production was temporarily halted, when an earthquake affected Tangshan’s factory, and production did not resume, until late 1979-early 1980.[7] The final steam locomotive built in China for use on national railways was SY-1772, completed at Tangshan, in October 1999.[12] After the end of commercial steam operations on Chinese main lines in 2005, some SYs still remained in service for some industrial firms, such as the Sandaoling Coal Mine Railway in the Xinjiang Uyghur Autonomous Region.[13] In April 2022, Sandaoling discontinued their regular steam operations, making them the final railway company in the world to end commercial service for steam locomotives.[13]
The SY class was also among the few Chinese steam locomotives to be exported to the United States. In 1989 and 1991, three SYs were constructed for tourist railroads in the United States, SY-1647M ('M' Chinese: 美国; pinyin: Měiguǒ; lit. 'America') for the Valley Railroad and SY-1658M for the Knox and Kane Railroad were built in 1989 at a cost of $300,000, with a third being built in 1991 for the New York, Susquehanna and Western Railway.[14][15] This third one was lost at sea during shipment in the Indian Ocean, when the ship it was on sunk, after encountering a major storm.[16][17]
The Susquehanna later purchased SY-1647M from the Valley Railroad, renumbering it as 142. No. 142 ran throughout the NYS&W system until its transfer to the New York Susquehanna & Western Technical & Historical Society in 2003 and now operates on the Belvidere and Delaware River Railway in Phillipsburg, New Jersey. SY1658m was renumbered 58 in the mid to late 1990s. After the main draw of the Knox and Kane Railroad, the Kinzua Bridge collapsed in mid 2003, the 58 was withdrawn from service and moved with other equipment to an engine house in Kane, Pennsylvania. On the morning of 16 March 2008, No. 58 was damaged when the engine house it was stored in was burned by arson. No. 58 was purchased later that year by the Valley Railroad at an auction.[18] Upon purchase, the 58 was renumbered 3025 and was given a complete rebuild which included cosmetic alterations to make it resemble a New Haven 2-8-2.
One was bought by the Korean National Railroad in 1994, numbered 901, and operated for excursion trains. It has been out of service since 2012.
Nos. 1647 and 1658 were 2 of the 6 Chinese steam locomotives to be exported to the United States, the others exported being QJ class Nos. 6988, 7040, 7081 and JS Class 8419.
^"Steam Rides Again! Chinese Engines, U.S. Rails". The New York Times. Dec 25, 1989.
^Hudson, Mike; Atkins, Philip (September 2007). "Locos lost at sea. The all-time definitive record". The Railway Magazine. 153 (1277). IPC Media Ltd: 14–19. ISSN0033-8923.
^"The Business Times". Singapore. June 10, 1991. p. 30.
Gibbons, Robin (2016). Locomotives of China - The JF6 Family - The JF6, PL2, YJ and SY Classes. United Kingdom: Tynedale Publishing. ISBN978-0-9934192-1-8.
SY-368 on display in front of the restaurant Gourmet Mansion in Nanjing
SY-0652 on display at the Dalian Modern Museum
SY-1000 on display at Liuzhou Locomotive and Rolling Stock Works
SY-1504 on display at Liuzhou Industrial Museum
SY-1658M (No. 3025) operating at Essex, Connecticut, in the United States
SY-1702 on display at Guilin University of Aerospace Technology
SY-3016 (KORAIL 901)
Rolling stock of Korail