Wisconsin Central 4-4-2 "Atlantic" Locomotives of 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 Raildata collection. 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.

Specifications 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 7.25'
Engine Wheelbase28'
Ratio of driving wheelbase to overall engine wheebase 0.26
Overall Wheelbase (engine & tender)55.65'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers88100 lbs
Engine Weight160400 lbs
Tender Light Weight113400 lbs
Total Engine and Tender Weight273800 lbs
Tender Water Capacity5000 gals
Tender Fuel Capacity (oil/coal)12 tons
Minimum weight of rail (calculated)73 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter79"
Boiler Pressure200 psi
Cylinders (dia x stroke)20" x 26"
Tractive Effort22380 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.94
Heating Ability
Firebox Area180 sq. ft
Grate Area48.32 sq. ft
Evaporative Heating Surface2634 sq. ft
Superheating Surface
Combined Heating Surface2634 sq. ft
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 area36000
Power L19844
Power MT492.67

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