Chicago & Alton 2-6-6-2 "Mallet Mogul" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class K1 (Locobase 9102)

Data from C&A 6-1918 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Mallet Articulated Compound for the Chicago & Alton", Railway & Locomotive Engineering, Vol (July 1910), p. 274.

In the same year that Brooks delivered the first of its L1 Mikados to the Alton (Locobase 9100), it supplied this trio of light Mallets. They apparently borrowed the same boiler design, but lengthened the tubes by a foot and included more flues. Like Mikes, the HP cylinders had 14" piston valves.

The R & LE report notes that the L1s could handle a 4,000-ton train from the Girard coal district near Atlanta, "...[e]xcept on the grade between Lawndale and Atlanta, which is 0.85 Per cent" To allow the Mikes to take the heavy trains all the way to Chicago, these Mallets were assigned to pusher service on the Atlanta hill.

One was sold almost immediately to the Chesapeake & Ohio and classed as an H-3, although it was quite different from the Chessie's other H-3s. It served the C & O until the late 1920s.

The other two persisted in pusher service until the Alton was taken over by the Baltimore & Ohio. The pair then traveled east, but into storage rather than into service and, without any further service, they were scrapped in 1938.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID9102
RailroadChicago & Alton (C&A)
Number in Class3
Road Numbers700-702
Number Built3
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)11 / 3.35
Engine Wheelbase (ft / m)48.08 / 14.65
Ratio of driving wheelbase to overall engine wheebase 0.23
Overall Wheelbase (engine & tender) (ft / m)74.62 / 22.74
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)318,004 / 144,244
Engine Weight (lbs / kg)365,004 / 165,563
Tender Loaded Weight (lbs / kg)205,600 / 93,259
Total Engine and Tender Weight (lbs / kg)570,604 / 258,822
Tender Water Capacity (gals / ML)11,000 / 41.67
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)18 / 16.40
Minimum weight of rail (calculated) (lb/yd / kg/m)88 / 44
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)62 / 1575
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)22" x 30" / 559x762
Low Pressure Cylinders (dia x stroke) (in / mm)35" x 30" / 889x762
Tractive Effort (lbs / kg)57,075 / 25888.82
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.57
Heating Ability
Firebox Area (sq ft / m2)227 / 21.10
Grate Area (sq ft / m2)63.30 / 5.88
Evaporative Heating Surface (sq ft / m2)4205 / 390.80
Superheating Surface (sq ft / m2)1117 / 103.81
Combined Heating Surface (sq ft / m2)5322 / 494.61
Evaporative Heating Surface/Cylinder Volume318.58
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12,660
Same as above plus superheater percentage15,319
Same as above but substitute firebox area for grate area54,934
Power L19523
Power MT396.12