Union Railroad class U-108b
Duluth, Missabe & Iron Range class S7
The Union Railroad was part of US Steel and was responsible for freight traffic between some of their plants and the main lines of several railroads in western Pennsylvania. The low speeds made it possible to design a locomotive with the largest possible adhesive weight without using a leading axle and without exceeding the length of the existing turntables. There was a booster on the first tender axle.
Since these locomotives were the only ones in North America with the 0-10-2 wheel arrangement, the name “Union” came about. The service at the Union Railroad ended in 1949 with the purchase of the first diesel locomotives. Nine of the ten locomotives were sold to the Duluth, Missabe and Iron Range, which also belonged to US Steel. They were retired there between 1958 and 1961 and DM&IR number 604 is now on display at Greenville, Pennsylvania.
Technical data
General
- Built
- 1936-1939
- Manufacturers
- Baldwin
- Wheel arrangement
- 0-10-2 (Union)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Wheelbase
- 9.75 m
- Total wheelbase
- 20.50 m
- Service mass
- 183.4 t
- Adhesion mass
- 156 t
- Total mass
- 292.3 t
- Rigid wheelbase
- 6.71 m
- Axle load
- 31.8 t
- Water capacity
- 45,425 l
- Fuel capacity
- 12.7 t (coal)
Boiler
- Grate area
- 7.92 m²
- Firebox surface
- 41.686 m²
- Tube heating surface
- 404.993 m²
- Evaporative heating surface
- 446.678 m²
- Superheater surface
- 129.042 m²
- Total heating surface
- 575.7 m²
Power plant
- Driver diameter
- 1,549 mm
- Boiler pressure
- 17.9 bar
- Expansion type
- simple expansion
- Cylinders
- two, 711 x 813 mm
Power
- Power source
- steam
- Estimated power
- 2,983 kW (4,056 PS)
- Starting effort
- 404.3 kN
- Starting effort booster
- 76.287 kN
Calculated values
- Factor of adhesion
- 1 : 3.79
- Optimal speed
- 45 km/h
- Power-to-weight ratio
- 16.3 kW/t
- Heating Surface Equivalent
- 913.2 m²
- Cylinder volume/HSE
- 1 : 707.17
- Adhesive weight/Total
- 1 : 1.18
- Tractive force/Heating surface
- 1 : 14.67
- Grate area/Heating surface
- 1 : 72.69
- Firebox/Tube surface
- 1 : 9.72
- Total/Superheater
- 1 : 3.46
