2-8-8-0

The locomotives were most likely retired in the late 1940s to early 1950s because of slow speeds on freight, hauling at 12 miles an hour.

[4] The western end of their network had ruling gradients greater than 2%, and the 2-8-8-0 offered exceptional tractive effort, enabling a single locomotive to move the heaviest freight trains.

This dates back to the colonial era, under the government of Dutch East Indies by their state railway company named Staatsspoorwegen (SS).

In the early 20th century, especially in West Java (known as Priangan), faced with the increase in passenger and freight rail traffic.

With a total weight of 133 tons, these locomotives have the profile of large American Mallets scaled down for narrow gauge (3 ft 6 in).

These were made based on Alco design but with a large number of refinements resulting in a 21 m (69 ft) length and 135-ton weight, being classed as 1250 (1251–1260).

After the back pressure was fixed, a double chimney was installed to maximize the engine performance, with the power output raised to 1,700 hp (1.3 MW) while driving at a constant speed of 45 km/h.

[6] During the Great Depression in the 1930s, SS withdrew their giant locomotives to save money on fuel and in response to declining traffic.

However, in 1938 these locomotives were reinstated to haul freight trains, except for the first batch of Class 1200s (which had been dismantled for parts).

[7] They were nicknamed Si Gombar or The Monster by locals along with CC50 counterparts due to their size and power in the mountain lines.

[8] Over time, the engines broke down due to poor condition and difficult maintenance, which hastened to their retirement.