Charles B Castner, writing in Drury (1993), notes that these were the first 4-8-4s in the South (where they were never referred to as "Northerns", but rather as "Dixies") and were derived from the USRA Light Mountains. Alco delivered an impressive machine on a one-piece cast-steel frame that carried brackets for auxiliary piping normally hung on the boiler. Castner also notes the "feedwater heaters, large fireboxes, and free-steaming boilers." The class soon acquired the nickname of "Gliders" for the smoothness with which they negotiated curves, an ease attributable to the lateral-motion axle boxes fitted to the first two driven axles.
J2s first ran on the Chattanooga Division in Eastern Tennessee, moving in 1940 to Atlanta and still later to Memphis. The Dixie Line returned to Alco for more 4-8-4s in 1942-1943; see Locobase 212.
Based on the J2s that appeared in 1930 (Locobase 8330) as enlargements of the J1 Mountains, this class had very few changes of note. Firebox heating surface included 116 sq ft of thermic syphons (97 sq ft/9 sq m) & arch tubes (19 sq ft/1.75 sq m). One noticeable difference was the much larger tender that held half again as much coal as that of the J2 and weighed 45 tons more. The engine's weight also increased by 10 tons.
570-579 were known as the "Yellow Jackets" because of a wide yellow stripe on the valence over the running gear. The later ten engines had painted edges but no valence and were known as "Stripes." Charles B Castner, writing in Drury (1993), notes and photos confirm that the Yellow Jackets had a neat appearance with a conical smokebox, retractable couplers in the pilots, and few pipes or pumps mounted on the boiler. Running gear was as might be expected in late-model steam engines: roller bearings throughout and Boxpok drivers.
For all their modern features, these engines were soon out of service, being withdrawn in 1951-1952 when diesels took over..
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||Nashville, Chattanooga & St. Louis (NC&StL)||Nashville, Chattanooga & St. Louis (NC&StL)|
|Number in Class||5||20|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||18.25||18.25|
|Engine Wheelbase (ft)||44.25||45.08|
|Ratio of driving wheelbase to overall engine wheebase||0.41||0.40|
|Overall Wheelbase (engine & tender) (ft)||82.58||86.31|
|Axle Loading (Maximum Weight per Axle) (lbs)|
|Weight on Drivers (lbs)||220,000||228,000|
|Engine Weight (lbs)||381,000||400,500|
|Tender Loaded Weight (lbs)||194,000||285,000|
|Total Engine and Tender Weight (lbs)||575,000||685,500|
|Tender Water Capacity (gals)||10,000||15,000|
|Tender Fuel Capacity (oil/coal) (gals/tons)||16||16|
|Minimum weight of rail (calculated) (lb/yd)||92||95|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||70||70|
|Boiler Pressure (psi)||250||250|
|High Pressure Cylinders (dia x stroke) (in)||25" x 30"||25" x 30"|
|Tractive Effort (lbs)||56,920||56,920|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.87||4.01|
|Firebox Area (sq ft)||444||454|
|Grate Area (sq ft)||77.30||77.30|
|Evaporative Heating Surface (sq ft)||4193||4203|
|Superheating Surface (sq ft)||1782||1782|
|Combined Heating Surface (sq ft)||5975||5985|
|Evaporative Heating Surface/Cylinder Volume||246.01||246.59|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||19,325||19,325|
|Same as above plus superheater percentage||25,123||25,123|
|Same as above but substitute firebox area for grate area||144,300||147,550|