Wisconsin Central 4-4-2 "Atlantic" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class K-20 (Locobase 8742)

Data from Soo Miscellaneous Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 26564-26573 in July 1902 and 37598-37602 in May 1905.

Brooks delivered these Atlantics from two orders in three batches - ten in June and December 1902, the last five in May 1905. Like most Atlantics, these engines no longer had a role to play once passenger trains had grown too heavy. They were never superheated and all were out of service by 1940.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID8742
RailroadWisconsin Central (Soo)
Number in Class15
Road Numbers257-271/2900-2914
Number Built15
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.25 / 2.21
Engine Wheelbase (ft / m)28 / 8.53
Ratio of driving wheelbase to overall engine wheebase 0.26
Overall Wheelbase (engine & tender) (ft / m)55.65 / 16.96
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)88,100 / 39,962
Engine Weight (lbs / kg)160,400 / 72,756
Tender Loaded Weight (lbs / kg)113,400 / 51,437
Total Engine and Tender Weight (lbs / kg)273,800 / 124,193
Tender Water Capacity (gals / ML)5000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12 / 10.90
Minimum weight of rail (calculated) (lb/yd / kg/m)73 / 36.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)79 / 2007
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)20" x 26" / 508x660
Tractive Effort (lbs / kg)22,380 / 10151.41
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.94
Heating Ability
Firebox Area (sq ft / m2)180 / 16.73
Grate Area (sq ft / m2)48.32 / 4.49
Evaporative Heating Surface (sq ft / m2)2634 / 244.80
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2634 / 244.80
Evaporative Heating Surface/Cylinder Volume278.62
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9664
Same as above plus superheater percentage9664
Same as above but substitute firebox area for grate area36,000
Power L19844
Power MT492.67

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