Chicago, Indianapolis & Louisville 4-4-2 "Atlantic" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class I-1 (Locobase 7088)

Data from C I & L 1 - 1940 locomotive diagram supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Just two Atlantics were ever delivered to the Monon. They were middle-of-the-pack engines that endured for more than three decades. They were superheated in the 1920s (Locobase 8314).

"Monon" is the common name for the Chicago, Indianopolis, and Louisville Railroad.


Class I-1-A (Locobase 8314)

Data from C I & L 8 - 1941 locomotive diagram supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

According to Drury (1993), the two Monon Atlantics (Locobase 7088) were retrofitted with Baker valve gear at the same time the piston valves were moved outside and the inboard-bearing trailing truck was replaced with a cast truck using outside bearings. But the C I & L's diagram shows Walschaert gear. Superheating the boiler and adding some direct heating surface area to the firebox (probably in the form of arch tubes) signficantly increased available power without sacrificing too much grip on the rail.

Even so, heavier passenger trains doomed this pair to retirement in 1936.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassI-1I-1-A
Locobase ID7088 8314
RailroadChicago, Indianapolis & Louisville (Monon)Chicago, Indianapolis & Louisville (Monon)
CountryUSAUSA
Whyte4-4-24-4-2
Number in Class22
Road Numbers390-391390-391
GaugeStdStd
Number Built2
BuilderBrooksMonon
Year19011921
Valve GearStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)7 / 2.137 / 2.13
Engine Wheelbase (ft / m)28.71 / 8.7528.25 / 8.61
Ratio of driving wheelbase to overall engine wheebase 0.24 0.25
Overall Wheelbase (engine & tender) (ft / m)56.46 / 17.2159.25 / 18.06
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)92,500 / 41,95795,000 / 43,091
Engine Weight (lbs / kg)167,300 / 75,886177,100 / 80,331
Tender Loaded Weight (lbs / kg)162,000 / 73,482152,000 / 68,946
Total Engine and Tender Weight (lbs / kg)329,300 / 149,368329,100 / 149,277
Tender Water Capacity (gals / ML)7400 / 28.037400 / 28.03
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)18 / 16.4013 / 11.80
Minimum weight of rail (calculated) (lb/yd / kg/m)77 / 38.5079 / 39.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)73 / 185473 / 1854
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)20.5" x 26" / 521x66020" x 26" / 508x660
Tractive Effort (lbs / kg)25,445 / 11541.6724,219 / 10985.57
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.64 3.92
Heating Ability
Firebox Area (sq ft / m2)163 / 15.15190 / 17.66
Grate Area (sq ft / m2)54.50 / 5.0754.50 / 5.07
Evaporative Heating Surface (sq ft / m2)2801 / 260.322063 / 191.73
Superheating Surface (sq ft / m2)490 / 45.54
Combined Heating Surface (sq ft / m2)2801 / 260.322553 / 237.27
Evaporative Heating Surface/Cylinder Volume282.00218.22
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,90010,900
Same as above plus superheater percentage10,90012,971
Same as above but substitute firebox area for grate area32,60045,220
Power L1885919,106
Power MT422.29886.77

Reference