Staatsspoorwegen class 800

The state railway of the Dutch East Indies on Java had the challenge of moving heavy loads on cape-gauge mountain lines with a maximum axle load of 9.5 tonnes and curve radii of up to 140 meters. They already had 33 2-6-6-0T Mallet locomotives of the class CC10 in service which had been built by German and Dutch manufacturers between 1904 and 1910. One of the drawbacks of the articulated design were the flexible steam lines which required a great deal of maintenance and tended to get leaky over time. So Hanomag proposed a tank locomotive with six coupled axles in a single frame.

In the class F10 locomotive developed as a result, the four inner driving axles were all fixed in the frame. Only the first and sixth driving axles could be moved laterally by 30 mm according to the Gölsdorf system, and the leading and trailing axles could be deflected laterally by 100 mm as Adams axles. The water tanks were mounted low between the frames in a new way. Now the boiler could be placed higher without raising the center of gravity to improve accessibility for maintenance.

16 were built by Hanomag between 1912 and 1915, followed by ten from Werkspoor in 1915 and 1917 and the final two from Hanomag in 1920. The total of 24 built were the first of only two types with the wheel arrangement 2-12-2T in history, which is why this wheel arrangement is also known as “Javanic”. On the line for which the locomotives were developed, there was a high level of wear on the wheel flanges. They were then moved to another mountain line that had larger curve radii. There they did very well. Today they are better known under the class designation F10 that was only assigned by the Japanese in 1942.