Nashville, Chattanooga & St. Louis 4-8-2 "Mountain" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class J-1a (Locobase 8329)

Data from NC&StL 6 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Firebox fitted with combustion chamber, which contributed to the firebox heating surface area as did 14 sq ft of arch tubes and 73 sq ft of thermic syphons. These were the standard USRA Light Mountain design. According to Charles B Castner, writing in Drury (1993), these J1s were immediately successful on the Chattanooga Division. Baldwin delivered 8 more with revised boilers and fireboxes in 1922 and 1925; see Locobase 212.

Although bumped from the premium runs by the J2 and J3 4-8-4s, the class ran until 1949-1951.


Class J-1b/c (Locobase 212)

Data from 1930 Locomotive Cyclopedia table and NC&StL 6 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Vol 68, pp. 329+. Works numbers were 55642 in September 1922, 55719-55720 in November, and 58386-58390 in May 1925.

After Alco's Richmond works supplied five USRA Light Mountain locomotives to the N, C & St L in 1919 (see Locobase 8329). When the 4-8-2 proved its worth, the road turned to Baldwin for more Mountains. Although the power dimensions were the same, the boiler saw a drop in small tubes in favor of more superheater flues. The firebox was fitted with combustion chamber, which contributed 107 sq ft (9.95 sq m) to the firebox heating surface area as did 27 sq ft (2.5 sq m) of arch tubes - the total was 348 sq ft.

Within a few years the supplementary heating area would be changed by removing two of the four arch tubes (leaving 14 sq ft (1.25 sq m) of arch tubes) and adding 76 sq ft of thermic syphons to arrive at a total of 411 sq ft of direct heating surface.

They served the NC & St L for more than 25 years before heading to the scrapyard in September 1949 (6) and October 1950 (556 and 558).

Specifications by Steve Llanso of Sweat House Media
ClassJ-1aJ-1b/c
Locobase ID8329 212
RailroadNashville, Chattanooga & St. Louis (NC&StL)Nashville, Chattanooga & St. Louis (NC&StL)
CountryUSAUSA
Whyte4-8-24-8-2
Number in Class58
Road Numbers550-554555-562
GaugeStdStd
Number Built58
BuilderAlco-RichmondBaldwin
Year19191922
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)18.2518.25
Engine Wheelbase (ft)4040
Ratio of driving wheelbase to overall engine wheebase 0.46 0.46
Overall Wheelbase (engine & tender) (ft)75.8377.33
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)224,500224,500
Engine Weight (lbs)327,000340,000
Tender Loaded Weight (lbs)192,000192,000
Total Engine and Tender Weight (lbs)519,000532,000
Tender Water Capacity (gals)10,00010,000
Tender Fuel Capacity (oil/coal) (gals/tons)1616
Minimum weight of rail (calculated) (lb/yd)9494
Geometry Relating to Tractive Effort
Driver Diameter (in)6969
Boiler Pressure (psi)200200
High Pressure Cylinders (dia x stroke) (in)27" x 30"27" x 30"
Tractive Effort (lbs)53,88353,883
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.17 4.17
Heating Ability
Firebox Area (sq ft)408411
Grate Area (sq ft)70.3070.30
Evaporative Heating Surface (sq ft)41814039
Superheating Surface (sq ft)9661080
Combined Heating Surface (sq ft)51475119
Evaporative Heating Surface/Cylinder Volume210.31203.17
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation14,06014,060
Same as above plus superheater percentage16,73117,013
Same as above but substitute firebox area for grate area97,10499,462
Power L117,25518,296
Power MT677.79718.68


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