Bulgarian State Railway series 600.76
The Bulgarian State Railways needed powerful freight locomotives for the narrow gauge railway in the Rhodopes with gradients of three percent and curve radii of 60 meters. These were based on the Reichsbahn class 9973-76 and had slightly larger wheels to reach a speed of 45 km/h. The first five were delivered by BMAG in Berlin, another ten were built in Poland by Fablok after the Second World War.
They fully met the requirements and were replaced by diesel locomotives of the class 75 in the 1960s. They were now used on other lines with lower gradients, where severe signs of wear showed up due to continuous operation at top speed. After eight locomotives were retired in 1977, the remaining ones were stored as a strategic reserve. Today four still exist, one of which is still operational.
Technical data
General
- Built
- 1940, 1949
- Manufacturers
- BMAG, Fablok
- Wheel arrangement
- 2-10-2T (Santa Fé)
- Gauge
- 760 mm (Bosnian gauge)
Dimensions and weights
- Length
- 11.26 m
- Wheelbase
- 8.00 m
- Empty mass
- 46.8 t
- Service mass
- 62 t
- Adhesion mass
- 50 t
- Rigid wheelbase
- 4.20 m
- Axle load
- 10 t
- Water capacity
- 7,000 l
- Fuel capacity
- 4 t (coal)
Boiler
- Grate area
- 2 m²
- Evaporative heating surface
- 87.6 m²
- Superheater surface
- 32.6 m²
- Total heating surface
- 120.2 m²
Power plant
- Driver diameter
- 850 mm
- Boiler pressure
- 16 bar
- Expansion type
- simple expansion
- Cylinders
- two, 460 x 400 mm
Power
- Power source
- steam
- Indicated power
- 625 kW (850 PS)
- Top speed
- 45 km/h
- Starting effort
- 135.4 kN
Calculated values
- Factor of adhesion
- 1 : 3.62
- Optimal speed
- 29 km/h
- Power-to-weight ratio
- 10.1 kW/t
- Adhesive weight/Total
- 1 : 1.24
- Tractive force/Heating surface
- 1 : 23.53
- Grate area/Heating surface
- 1 : 60.10
- Total/Superheater
- 1 : 2.69
