0-4-4-2

Other equivalent classifications are: 0-4-4-2Ts were the first-generation mallets used by Indonesia since the colonial period in late 19th to early 20th century, when Staatsspoorwegen (the state railway company of the Dutch East Indies) ordered 12 units from Hartmann and 4 from Schwartzkopff in 1899–1908, classified as SS Class 500 (501–516) for use on mountain lines in West Java.

These locomotives worked mixed trains that transported plantation crops and passengers on the Buitenzorg–Bandung line which opened in 1884.

[1] These oil-burned engine had power output of 465 hp (347 kW), which was more powerful and suitable for running the winding mountain terrain with ease compared to older SS locomotives the 2-6-0T (SS Class 300 or DKA C11 and SS Class 400 or DKA C12) which are smaller and slower in size and engine power.

During Japanese occupation in 1942, these locomotives were renumbered to BB10 and used on Saketi–Bayah railway construction which was used as Japanese war effort for coal transports to the southern coast of West Java as from coal mining in Cikotok.

[2] This line was also known as "Death Railway" due to its construction using Japanese PoWs and local residents which were known as romusha or force laborers.