Staatsspoorwegen 4-6-4 Locomotives in Indonesia

Class C27 (Locobase 4737)

Data from "4-6-4 Tank Locomotive, Java State Railways", Locomotive Magazine, Volume XXV [25], whole no. 326 (15 October 1919), pp. 163-164. See also [], a site for the Ambarawa Railway Museum maintained by Rob Dickinson. See also "PNKA Wallahs Part 5 - part of a series of pages by Tony Ford describing the Perusahaan Negara Kereta Api ca 1970" on the international steam website at []; and Glen Allison, "Ambarawa Railway Museum, Java, Indonesia", part of the Steam Punk Train website at [], both last accessed 3 June 2020. . SLM (works number 2575-2588 in 1916), Werkspoor (439-448 in 1919, 469-478 in 1920), and Armstrong Whitworth (180-184 in 1922).

See Indra Krishnamurti at [] for building dates and numbers both of predecessor railways and the Indonesian State Railways. These Hudson tanks were ordered as early as 1916, but even though Switzerland was neutral in World War I, it had difficulty obtaining components and material and the first were delivered two years later.

Narrow gauge and tight curves dictated flexibility and a short adhesion wheelbase. The front bogie traversed 70 mm to each side while the rear bogie enjoyed 80 mm of play. LM described the valve motion as "well-proportioned and light in weight-an important matter, " the report continued, "with locomotives having relatively small wheels and consequently developing considerable reciprocating velocities in the motion at high speed."

The water tanks were set below the boiler between the frames which conferred "ample" water capacity "without unduly raising the centre of gravity or provoling excessive lateral overhang."

"These locomotives were used on routes from Jakarta Kota to Yogyakarta and from Kertosono to Blitar, Malang, Jember, and Banyuwangi." They could reach speeds of 80 kph (50 mph).

The class was described by Tony Ford in 1970 as "fine C27 4-6-4T, used for passenger and mixed work throughout Java. These Swiss designed superheated locomotives, built post First World War have survived the test of time well, with three quarters of the original 39 locomotives still in service [in 1970]."

Class C28 (Locobase 4738)

Data from Indra Krishnamurti's [] . See also "New 'Baltic' Type Tank Locomotive, for the Java State Rys", Locomotive Magazine, Volume XXIX [29] (15 December 1923), p. 358-359.

German manufacturers delivered this large class of Hudson tanks, which seem to have been scaled-up versions of the C27. Henschel ( works numbers were 18155-18184 in 1921), Hartmann (4426-4440 in 1921), and Esslingen (4022-4034 in 1922).

Indra Krishnamurti shows a variant with a slightly different EHS (141.6 sq m/1,524 sq ft) and smaller grate (2.8 sq m/30.13 sq ft).

A C28 is credited with the fastest Indonesian speed recorded, reaching 110 kph (68 mph) in 1920.