Buffalo, Rochester & Pittsburgh class WW
Baltimore & Ohio classes P-17 and P-18
The first Pacifics ordered by the BR&P were designated class WW. Their driver diameter was a modest 73 inches and the cylinders measured 24.5 inches in diameter and had a stroke of 26 inches. This resulted in a starting tractive effort of 36,000 pounds. The valve gear was of the Walschaerts type. The superheated boiler was of the same design as the one used on the class Z Mikados.
The first three were built by ALCO-Brooks in 1912, followed by six more in 1913. Another batch of eight was built in 1918. Their running numbers were 600 to 616. When the BR&P became part of the Baltimore & Ohio in 1932, the first two batches became class P-17 and the last batch became class P-18. The class was retired in 1953.
Technical data
General
- Built
- 1912-1913, 1918
- Manufacturers
- ALCO
- Wheel arrangement
- 4-6-2 (Pacific)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Length
- 22.51 m
- Wheelbase
- 10.14 m
- Rigid wheelbase
- 3.96 m
- Total wheelbase
- 20.08 m
- Service weight
- 117 t
- Adhesive weight
- 74.2 t
- Axle load
- 27.7 t
- Total weight
- 194.8 t
- Water capacity
- 35,015 l
- Fuel capacity
- 12.7 t (coal)
Boiler
- Grate area
- 5.249 m²
- Firebox surface
- 21.739 m²
- Tube heating surface
- 315.035 m²
- Evaporative heating surface
- 336.774 m²
- Superheater surface
- 69.677 m²
- Total heating surface
- 406.5 m²
Power plant
- Driver diameter
- 1,854 mm
- Boiler pressure
- 13.8 bar
- Expansion type
- simple expansion
- Cylinders
- two, 622 x 660 mm
Power
- Power source
- steam
- Estimated power
- 1,790 kW (2,434 PS)
- Starting effort
- 161.7 kN
Calculated values
- Factor of adhesion
- 1 : 4.50
- Optimal speed
- 68 km/h
- Power-to-weight ratio
- 15.3 kW/t
- Heating Surface Equivalent
- 584.8 m²
- Cylinder volume/HSE
- 1 : 686.91
- Adhesive weight/Total
- 1 : 1.58
- Tractive force/Heating surface
- 1 : 8.31
- Grate area/Heating surface
- 1 : 77.43
- Firebox/Tube surface
- 1 : 14.49
- Total/Superheater
- 1 : 4.83
