Nordhausen-Wernigerode Railway No. 51 and 52
German Reichsbahn class 99601
Germany 1922 2 produced
The Nordhausen-Wernigeroder Eisenbahn, better known for the Brocken Railway in the Harz mountains, got two Mallets from Borsig in 1922 and 1924. They had a 2-4-4-2 wheel arrangement and were fairly heavy for meter gauge. Due to the very short rigid wheelbase of only 1,300 mm (4 ft 3 in), they had insufficient running characteristics and tended to derail. Furthermore, they were not reliable.
In 1949, both were taken over by the Reichsbahn as 99 6011 and 6012. They were put out of service in the Harz in 1956. 99 6011 was brought to the Gera-Pforten–Wuitz-Mumsdorf line and only used there for a brief period. It was ultimately retired in 1966, as it had been the case with 99 6012 already in 1964.
Technical data
General
- Built
- 1922, 1924
- Manufacturers
- Borsig
- Wheel arrangement
- 2-4-4-2T (Skookum (Mallet))
- Gauge
- 1,000 mm (Meter gauge)
Dimensions and weights
- Length
- 10.35 m
- Wheelbase
- 7.80 m
- Empty mass
- 43.5 t
- Service mass
- 53 t
- Adhesion mass
- 39 t
- Rigid wheelbase
- 1.30 m
- Axle load
- 9.8 t
- Water capacity
- 6,000 l
- Fuel capacity
- 2.5 t (coal)
Boiler
- Grate area
- 1.99 m²
- Evaporative heating surface
- 85.89 m²
- Superheater surface
- 22 m²
- Total heating surface
- 107.9 m²
Power plant
- Driver diameter
- 850 mm
- Boiler pressure
- 14 bar
- Expansion type
- compound
- Cylinders
- four, HP: 360 x 400 mm and LP: 560 x 400 mm
Power
- Power source
- steam
- Indicated power
- 480 kW (653 PS)
- Top speed
- 30 km/h
- Starting effort
- 102.7 kN
- Starting effort simple
- 123.2 kN
Calculated values
- Factor of adhesion
- 1 : 3.73
- Optimal speed
- 29 km/h
- Power-to-weight ratio
- 9.1 kW/t
- Adhesive weight/Total
- 1 : 1.36
- Tractive force/Heating surface
- 1 : 19.88
- Grate area/Heating surface
- 1 : 54.22
- Total/Superheater
- 1 : 3.90
