Data from A E Durrant The Steam Locomotives of Eastern Europe (Newton Abbot:David & Charles, 1972); and "BHStB IIIb5" in Wikipedia at "[], last accessed 28 September 2025 . See also "73-019
Dampflokomotive der Pinzgauer Lokalbahn", retrieved from the Wayback machine at [][], [], later []). Krauss-Linz works numbers were 5700, 5770-5771 in 1907, 5963-5971 in 1908, 6479-6481 in 1911. MAVAG works numbers 2829-2830 in 1911, 3286-3291 in 1913.
This was an express locomotive that was rated at up to 60 kph (38 mph) on its tiny drivers, quite a speed for the Bosnian countryside through which it ran. Tight curves led to the use of the Krauss-Helmholz truck, which combined the pony truck and the first coupled axle, and lateral play in the other two driven axles. Taking into account the radial trailing truck means the design had no fixed wheelbase. After the Clench-Goldsdorf steam dryer proved insufficient, the railway fitted a Schmidt firetube superheater, which dictated piston valves to handle the higher temperaturers.
Wikipedia reports that the "locomotives proved themselves to be very reliable", a contention supported by the fact that as late as 1965, all but one remained in service. They could scale a 0.8% grade at 45 kph (28 mph) hauling 125 tons At 40 kph (25 mph) climbing a 1% grade, these little engines managed 160 tons.
The particular example preserved at the Frojach Museum remained in service into the 1970s.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | IIIb5/73 |
| Locobase ID | 4805 |
| Railroad | Bosnia-Herzogovina |
| Country | Austria |
| Whyte | 2-6-2 |
| Number in Class | 23 |
| Road Numbers | 151-173/73.001-.023 |
| Gauge | 76 cm |
| Number Built | 23 |
| Builder | MAVAG |
| Year | 1913 |
| Valve Gear | Heusinger |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 8.53 / 2.60 |
| Engine Wheelbase (ft / m) | |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | 36.58 / 11.15 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 47,620 / 21,600 |
| Engine Weight (lbs / kg) | 67,461 / 30,600 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1320 / 5 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 2.20 / 2 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 26 / 13 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 47.20 / 1200 |
| Boiler Pressure (psi / kPa) | 176.30 / 1200 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 14.57" x 17.72" / 370x450 |
| Tractive Effort (lbs / kg) | 11,943 / 5417.26 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.99 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 99 - 1.732" / 44 |
| Flues (number - dia) (in / mm) | 15 - 4.764" / 121 |
| Flue/Tube length (ft / m) | 12.14 / 3.70 |
| Firebox Area (sq ft / m2) | 60.71 / 5.64 |
| Grate Area (sq ft / m2) | 16.68 / 1.55 |
| Evaporative Heating Surface (sq ft / m2) | 833 / 77.42 |
| Superheating Surface (sq ft / m2) | 175 / 16.26 |
| Combined Heating Surface (sq ft / m2) | 1008 / 93.68 |
| Evaporative Heating Surface/Cylinder Volume | 243.60 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2941 |
| Same as above plus superheater percentage | 3441 |
| Same as above but substitute firebox area for grate area | 12,523 |
| Power L1 | 10,998 |
| Power MT | 1527.49 |