The reference for locomotives and railcars
Chicago, Milwaukee, St. Paul & Pacific (Milwaukee Road) class F6
United States | 1929 | 22 produced
F6 No. 128, the original No. 6403, was in service until February 1954
F6 No. 128, the original No. 6403, was in service until February 1954
collection Taylor Rush

The first Hudsons of the Milwaukee Road were built by Baldwin between 1929 and 1931. While the first 14 locomotives were designated as class F6 and their running boards were broken above the air tank, the last eight were designated as F6a and had straight running boards. They were delivered with driving wheels with a diameter of 79 inches, which later increased to 80 inches due to thicker tires. The coffin feed water heater was apparently integrated into the smokebox for aesthetic reasons.

The boiler had a large firebox, which resulted in a load on the trailing bogie of around 53 tons. The express trains they hauled usually consisted of nine to ten cars, but often eleven to 14 cars and were occasionally even longer. With these trains, the 918-mile round trip between Minneapolis and Harlowton could be completed ten times in 30 days without any servicing stops. A lighter train covered a flat section of 65.6 miles at an average of 92.3 mph

Axle config4-6-4 (Hudson) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Wheelbase40 ft 9 in
Fixed wheelbase14 ft
Total wheelbase81 ft 7 in
Service weight380,220 lbs
Adhesive weight196,550 lbs
Total weight668,000 lbs
Axle load65,517 lbs
Water capacity15,000 us gal
Fuel capacity40,000 lbs (coal)
Power sourcesteam
Estimated power3,700 hp (2,759 kW)
Optimal speed52 mph
Starting effort45,250 lbf
Power Plant
Driver diameter80 in
Boiler pressure225 psi
Expansion typesimple
Cylinderstwo, 26 x 28 in
Grate area80 sq ft
Firebox area411 sq ft
Tube heating area3,794 sq ft
Evaporative heating area4,205 sq ft
Superheater area1,815 sq ft
Total heating area6,020 sq ft
Calculated Values
steam locomotive
last changed: 11/2023

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