Virginian 4-6-2 "Pacific" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class PA (Locobase 174)

Data from VGN 8 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error.) Works numbers were 61992-61996 in September 1920, 61997 in October.

Note the low drivers on this mountain-climbing Pacific. Like the TA Ten-wheelers, these were built by Richmond in a single batch

Boilers originally pressed at 190 psi (13.1 bar). Fitted with Duplex stokers. EW King, Jr (in Drury, 1993) says another distinguishing feature was "their two cross-compound air pumps under the left running board." Another was the relatively generous 14" (356 mm) piston valves.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID174
RailroadVirginian (VGN)
Number in Class6
Road Numbers210-215
Number Built6
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.17 / 3.71
Engine Wheelbase (ft / m)34.75 / 10.59
Ratio of driving wheelbase to overall engine wheebase 0.35
Overall Wheelbase (engine & tender) (ft / m)70.60 / 21.52
Axle Loading (Maximum Weight per Axle) (lbs / kg)63,800 / 28,939
Weight on Drivers (lbs / kg)189,000 / 85,729
Engine Weight (lbs / kg)298,000 / 135,171
Tender Loaded Weight (lbs / kg)188,100 / 85,321
Total Engine and Tender Weight (lbs / kg)486,100 / 220,492
Tender Water Capacity (gals / ML)10,500 / 39.77
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.70
Minimum weight of rail (calculated) (lb/yd / kg/m)105 / 52.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)69 / 1753
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)26" x 28" / 660x711
Tractive Effort (lbs / kg)46,634 / 21152.85
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.05
Heating Ability
Firebox Area (sq ft / m2)293 / 27.23
Grate Area (sq ft / m2)66.70 / 6.20
Evaporative Heating Surface (sq ft / m2)3414 / 317.29
Superheating Surface (sq ft / m2)905 / 84.11
Combined Heating Surface (sq ft / m2)4319 / 401.40
Evaporative Heating Surface/Cylinder Volume198.42
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,340
Same as above plus superheater percentage16,141
Same as above but substitute firebox area for grate area70,906
Power L117,410
Power MT609.24

All material Copyright ©
Wes Barris