Washington & Plymouth 4-4-2 "Atlantic" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 10 (Locobase 10790)

Data from Baldwin Locomotive Works, Record of Recent Construction ((1903), No. 39, p.282-283. See also DeGolyer, Volume 24, p. ; and George Woodman Hilton, American Narrow-Gauge Railroads (Stanford, Calif: Stanford University Press, 1990), p. 485. Works number was 20151 in February 1902.

Built in 1889, the W&P connected the two North Carolina towns with 33 miles (53 km) of track until 1904, when it was converted to standard gauge and merged into the Norfolk & Southern.

This tiny wood-burning 4-4-2 is a delightful miniature that stretched the definition of "Atlantic" beyond any other incarnation. It was bought to serve the passenger service that began in 1902 and may have used the trailing axle to carry the large grate necessitated by the fuel described as "poor wood". But its driver diameter/gauge ratio put it squarely in the mixed traffic category and the tire specs spelled out its dual role.

Clearly, the railroad and the builder were working within tight margins where performance and weight limits opposed each other. A spec note resolved the conflict: Company will accept the additional weight of changes in wheels and tubes." Locobase can't tell what these changes might have been, but suspects that the original proposal was undersized for the traffic requirement.

George Hilton reported that the 10 was the only Atlantic to operate on any American narrow-gauge line.

When the W&P converted to standard gauge, 10 was sold to the Norfolk County Lumber Company. From there, the engine went to the Wellington & Powellsville (aka the Walk & Push) and renumbered 9. It operated until 1926, when the W&P converted to standard gauge.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID10790
RailroadWashington & Plymouth
Number in Class1
Road Numbers10
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)4 / 1.22
Engine Wheelbase (ft / m)16.83 / 5.13
Ratio of driving wheelbase to overall engine wheelbase 0.24
Overall Wheelbase (engine & tender) (ft / m)38.12 / 11.62
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)23,740 / 10,768
Engine Weight (lbs / kg)45,060 / 20,439
Tender Loaded Weight (lbs / kg)29,940 / 13,581
Total Engine and Tender Weight (lbs / kg)75,000 / 34,020
Tender Water Capacity (gals / ML)1500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)20 / 10
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)10" x 18" / 254x457
Tractive Effort (lbs / kg)5464 / 2478.43
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.34
Heating Ability
Tubes (number - dia) (in / mm)90 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)10.58 / 3.22
Firebox Area (sq ft / m2)52 / 4.83
Grate Area (sq ft / m2)12.40 / 1.15
Evaporative Heating Surface (sq ft / m2)485 / 45.07
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)485 / 45.07
Evaporative Heating Surface/Cylinder Volume295.73
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1860
Same as above plus superheater percentage1860
Same as above but substitute firebox area for grate area7800
Power L14770
Power MT885.93

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