Richmond, Fredericksburg & Potomac 4-8-2 "Mountain" Type Locomotives

Class 501 (Locobase 221)

Data from 1937 RF & P locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

Delivered in pairs in 1924 & 1925 with boilers pressing 200 psi, but later increased to 225 psi. Firebox heating surface included 95 sq ft of syphons, 16 sq ft of arch tubes.

They lasted until 1950.

Specifications
Class501
Locobase ID221
RailroadRichmond, Fredericksburg & Potomac
Whyte4-8-2
Road Numbers501-504
GaugeStd
BuilderAlco-Richmond
Year1924
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase20'
Engine Wheelbase42.17'
Ratio of driving wheelbase to overall engine wheebase 0.47
Overall Wheelbase (engine & tender)81.75'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers262000 lbs
Engine Weight381000 lbs
Tender Light Weight201600 lbs
Total Engine and Tender Weight582600 lbs
Tender Water Capacity10000 gals
Tender Fuel Capacity (oil/coal)16 tons
Minimum weight per yard of rail on which locomotive could run109.17 lb rail
Geometry Relating to Tractive Effort
Driver Diameter73"
Boiler Pressure225 psi
Cylinders (dia x stroke)28" x 30"
Tractive Effort61619 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.25
Heating Ability
Firebox Area465 sq. ft
Grate Area75 sq. ft
Evaporative Heating Surface4762
Superheating Surface1190
Combined Heating Surface5952
Evaporative Heating Surface/Cylinder Volume222.73
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation16875
Same as above plus superheater percentage20248.87
Same as above but substitute firebox area for grate area125542.97
Power L122787.02
Power MT766.97

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.