Spokane Portland & Seattle O-3, 539
Former Northern Pacific W-3, 1762

                 Classification: 2-8-2, Mikado
                     Year Built:  September, 1917
                        Builder:  American Locomotive Company (ALCO) Brooks Locomitve Works at Dunkirk, NY
               Builder's Number:  57954
    Original Cost of locomotive:  $36,631
            Cost plus additions:  $40,995
   Loaded Weight(Engine&Tender):  533,600 pounds
         Working Steam Pressure:  200 psi
                     Grate Area:  70.3 square inches
             Combustion chamber:  36" long
                          flues:  216 - 2-1/4" diameter flues; length 18 feet
                                  40 - 5-1/2" diameter flues; length 18 feet 
                     Arch Tubes:  4 - 3-1/2" diameter
         Heating surface, total:  4479 square feet  
                    Superheater:  Schmidt Class A
              Cylinder Diameter:  28 inches
                Cylinder Stroke:  30 inches
                Driver Diameter:  63 inches
                     Horsepower:  4700
                Tractive Effort:  63,460 pounds
                     Valve Gear:  Walschaerts
             Total Weigh Loaded:  583,600 pounds (291 tons)
             Total Weight Empty:  478,905 pounds (239 tons)
             Engine Weight Only:  335,300 pounds (167 tons)
              Weight on Drivers:  244,800 pounds (122 tons)
                   Water Weight:  83,300 pounds (41 tons)
                 Water Capacity:  10,000 US Gallons
                    Fuel Weight:  21,395 pounds (10 tons)
                  Fuel Capacity:  4,500 US Gallons
   Wheel Base (between drivers):  5'7"
               Rigid Wheel Base:  16'6"
        Total Engine Wheel Base:  35'4"
        Total Tender Wheel Base:  15'
Total Length of Engine & Tender:  80'6"
                Width of Engine:  10'6"
               Hieght of Engine:  15"7"