Data from [], a site for the Ambarawa Railway Museum maintained by Rob Dickinson. See also "Lokomotif B27" in Wikipedia (translated by Google) at [], last accessed 24 August 2026. Indra Krishnamurti at [] for building dates and numbers both of predecessor railways and the Indonesian State Railways. Works numbers were 3532-3537 in 1912, 3753-3758 in 1914, and 4441-4444 in 1921.
According to Wikipedia, industrial growth in Semarang , a major Central Java port city on the Java Sea, prompted construction in 1902 of a rail line running northeast to Demak then southeast to Purowadi, then east (ish) to arrive in Blora 130 km (80.75 miles) from Semarang. Increasing demands for both freight and passenger service from the interior to Semarang led to upgrades on the line.
To provide passenger power, the SJS bought this four-coupled, superheated design from Hartmann in three batches. The railway set the B27's maximum speed at 45 kph (28 mph). Like many Indonesian steam locomotives, the firebox could burn either coal or teak. They were busy--Wikipedia cites a 1928 report showing 706,767 passengers arrived in Semarang that year.
Only two of the class avoided dismantling, according to Wikipedia. "B2705 (which entered service in 1912) is on display at the Transportation Museum in Taman Mini Indonesia Indah (Jakarta), while the B2711 (which entered service in 1914) is exhibited at the Ambarawa Railway Museum (Central Java)."
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | B27 |
| Locobase ID | 4718 |
| Railroad | Samarang-Joana Stoomtram Mij |
| Country | Indonesia |
| Whyte | 0-4-2T |
| Number in Class | 16 |
| Road Numbers | 201-216/B2701-B2716 |
| Gauge | 3'6" |
| Number Built | 16 |
| Builder | Hartmann |
| Year | 1912 |
| Valve Gear | Heusinger |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | |
| Engine Wheelbase (ft / m) | |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 35,715 / 16,200 |
| Engine Weight (lbs / kg) | 49,383 / 22,400 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 30 / 15 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 39.40 / 1001 |
| Boiler Pressure (psi / kPa) | 170.70 / 1180 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 14.96" x 15.75" / 380x400 |
| Tractive Effort (lbs / kg) | 12,981 / 5888.09 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 2.75 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | |
| Grate Area (sq ft / m2) | 8.61 / 0.80 |
| Evaporative Heating Surface (sq ft / m2) | 377 / 35 |
| Superheating Surface (sq ft / m2) | 108 / 10 |
| Combined Heating Surface (sq ft / m2) | 485 / 45 |
| Evaporative Heating Surface/Cylinder Volume | 117.66 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1470 |
| Same as above plus superheater percentage | 1793 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |