The locomotive later known as BB10 was the first Mallet in service in Indonesia. Mainly built for the hilly and winding Bogor-Bandung line, it was a tank locomotive with two two-axle driver groups and a trailing axle. The first eight were delivered by Hartmann of Chemnitz in 1899 and were numbered 501 to 508. Originally coal-fired, they had an output of 465 hp.
Hartmann delivered four more in 1907 which were numbered 509 to 512 and were intended for work on other lines. Another four came from BMAG of Berlin in 1908 which became numbers 513 to 516. Later they were converted to burn oil and the Japanese gave them the designation BB10. Only BB10 12 was preserved and is on display in the Indonesian Railway Museum at Ambarawa.