Nashville, Chattanooga & St Louis 4-8-0 "Mastodon" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class I1-44 (Locobase 14418)

Data from NC&StL 1 - 1921 Locomotive Diagrams and Cranes supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

The Butte, Anaconda & Pacific bought three cross-compound Mastodons from Schenectady in 1897; see Locobase 14417. After the BA&P's electrification was completed in 1914, the class was idled until it was sold in 1917 to the as their class I1-44; they were renumbered 850-852. In 1920, all three engines were slightly modified in a significant way when the LP cylinder was removed and a second 23" HP cylinder was fitted instead. In an effort to encourage adhesion, the altering railroad (either the BA&P or the Nashville, Chattanooga & St Louis) also reduced the boiler pressure by 40 psi (2.75 bar). Even so, a look at the data shows that these engines were still likely to be slippery.

The NC&StL operated the engines in transfer service or as heavy switchers for a decade or more. In 1924, the NC&StL installed a superheater in 850; see Locobase 14419. Two years later, the railroad retired the 852 in September 1926. The 850 followed in November 1927 and the 851 in May 1932.

Class I1-44 - superheated (Locobase 14419)

Data from NC&StL 1 - 1921 Locomotive Diagrams and Cranes supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

The Dixie Line must have wondered after they converted their three adopted cross-compound Mastodons to simple expansion whether this big switcher/transfer engine trio could have extended lives if they were fitted with a modest degree of superheat. So they installed a small Schmidt-type unit in the 850 in 1924. Results must have disappointed as the 850 was scrapped November 1927, after the 852 and five years before the 851..

Specifications by Steve Llanso of Sweat House Media
ClassI1-44I1-44 - superheated
Locobase ID14418 14419
RailroadNashville, Chattanooga & St LouisNashville, Chattanooga & St Louis
Number in Class31
Road Numbers850-852850
Number Built
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase15.75'15.75'
Engine Wheelbase26.75'26.75'
Ratio of driving wheelbase to overall engine wheebase 0.59 0.59
Overall Wheelbase (engine & tender)53.83'53.83'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers154000 lbs154000 lbs
Engine Weight193000 lbs193000 lbs
Tender Light Weight112000 lbs108000 lbs
Total Engine and Tender Weight305000 lbs301000 lbs
Tender Water Capacity4500 gals4500 gals
Tender Fuel Capacity (oil/coal)9.5 tons9.5 tons
Minimum weight of rail (calculated)64 lb/yard64 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"56"
Boiler Pressure170 psi170 psi
Cylinders (dia x stroke)23" x 32"23" x 32"
Tractive Effort43680 lbs43680 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.53 3.53
Heating Ability
Firebox Area206.51 sq. ft232.50 sq. ft
Grate Area35 sq. ft35 sq. ft
Evaporative Heating Surface2928 sq. ft2358 sq. ft
Superheating Surface320 sq. ft
Combined Heating Surface2928 sq. ft2678 sq. ft
Evaporative Heating Surface/Cylinder Volume190.28153.24
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation59505950
Same as above plus superheater percentage59506664
Same as above but substitute firebox area for grate area3510744268
Power L140846600
Power MT233.86377.93

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