Western Pacific 4-8-4 "Northern" Type Locomotives

Class GS-64-77 (Locobase 6681)

Data from WP 3 - 1949 Steam locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

Piggy-backing on a Southern Pacific order for its GS-6s was the Western Pacific, which took delivery of this sextet in 1943. http://www.wplives.com/motivepower/srosters/Class_481_Roster__/class_481-407_roster__.html (accessed 3 July 2006) shows that the unit price was $206,655.

According to Drury (1993), certain devices that held SP patents, like the oil burner, were removed, but the pointed smokebox remained. After World War II, the WP added smoke deflectors. The GS-64s went of service in the early 1950s, 485 operating last in October 1951 and both 483 and 486 closing out in January 1953. Three were then sold to the Southern Pacific for parts.

Specifications
ClassGS-64-77
Locobase ID6681
RailroadWestern Pacific (WP)
Whyte4-8-4
Road Numbers481-486
GaugeStd
BuilderLima
Year1943
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase20'
Engine Wheelbase45.83'
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender)94.42'
Axle Loading (Maximum Weight per Axle)70237 lbs
Weight on Drivers280950 lbs
Engine Weight465100 lbs
Tender Light Weight397700 lbs
Total Engine and Tender Weight862800 lbs
Tender Water Capacity23300 gals
Tender Fuel Capacity (oil/coal)6000 gals
Minimum weight per yard of rail on which locomotive could run117.06 lb rail
Geometry Relating to Tractive Effort
Driver Diameter73.50"
Boiler Pressure260 psi
Cylinders (dia x stroke)27" x 30"
Tractive Effort65759 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.27
Heating Ability
Firebox Area451 sq. ft
Grate Area90.20 sq. ft
Evaporative Heating Surface4922
Superheating Surface2086
Combined Heating Surface7008
Evaporative Heating Surface/Cylinder Volume247.58
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation23452
Same as above plus superheater percentage30432.72
Same as above but substitute firebox area for grate area152163.59
Power L141575.61
Power MT1304.98

Credits

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