Chicago, Burlington & Quincy 4-6-4 "Hudson" Type Locomotives

Class S-4 (Locobase 181)

Twelve by Baldwin, a thirteenth (S-4A) by the West Burlington shops using a Baldwin boiler. All but 4001 had Elesco feedwater heaters; 4001 had a Worthington. Other goodies included a Barco Type 4 power reverse gear, Type B stokers, and 14" diameter pistons. Firebox heating surface included 43 sq ft of arch tubes and 70 sq ft of combustion chamber.

Corbin & Kerka (1960, p 106) report that when these locomotives went into service pulling such trains as the Ak-Sar-Ben, the Aristocrat, and the Black Hawk, the Burlington was able to do away with swapping one locomotive for another during the trip. One is credited with hauling 10 standard passenger cars between Cochrane and La Crosse (Wis) at 112 mph. The authors conclude "The 4-6-4 types were perhaps the some of the most successful locomotives used on the Chicago, Burlington & Quincy."

One (3002) was streamlined to resemble the stainless-steel Zephyrs, renumbered 4000 and called Aeolus and nicknamed "Big Alice the Goon." After her success, a second was built from scratch and numbered 4002.

The modification, dubbed S-4A, was more than cosmetic. They also received Box-Pok drivers and roller bearings in the lightweight side rods. Three more S-4s (3008, 3009, and 3011) received the running gear upgrades in 1938, but not the shrouds. They were renumbered 4003-4005.

Corbin & Kerka (1960); Railway Age 7 March 1931; and locomotive diagram published on Vernon Beck's website -- http://home.earthlink.net/~vnlbeck/S/s4j.tif (accessed 22 March 2003)

Specifications
ClassS-4
Locobase ID181
RailroadChicago, Burlington & Quincy (CB&Q)
Whyte4-6-4
Road Numbers3000-3012
GaugeStd
BuilderBaldwin
Year1930
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase13.67'
Engine Wheelbase39.92'
Ratio of driving wheelbase to overall engine wheebase 0.34
Overall Wheelbase (engine & tender)82.23'
Axle Loading (Maximum Weight per Axle)69780 lbs
Weight on Drivers207730 lbs
Engine Weight391880 lbs
Tender Light Weight326050 lbs
Total Engine and Tender Weight717930 lbs
Tender Water Capacity15000 gals
Tender Fuel Capacity (oil/coal)24 tons
Minimum weight per yard of rail on which locomotive could run115.41 lb rail
Geometry Relating to Tractive Effort
Driver Diameter78"
Boiler Pressure250 psi
Cylinders (dia x stroke)25" x 28"
Tractive Effort47676 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.36
Heating Ability
Firebox Area369 sq. ft
Grate Area87.90 sq. ft
Evaporative Heating Surface4247
Superheating Surface1830
Combined Heating Surface6077
Evaporative Heating Surface/Cylinder Volume266.97
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation21975
Same as above plus superheater percentage28592.45
Same as above but substitute firebox area for grate area120029.74
Power L146094.25
Power MT1467.58

Credits

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