Alabama, Tennessee & Northern 2-10-0 "Decapod" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class 401 (Locobase 11371)

Data from DeGolyer, Volume 77, pp. 612+. Works numbers for the AT&Ns were 60340-60341 in January 1928 and 60704 in January 1929. (Thanks to Chris Hohl for his 7 March 2016 email correcting the tender weights and capacities.) For AT&N history, see http://www.frisco.org/vb/showthread.php?t=1181 and

In 1912, the AT&N joined with the Tombigbee Valley Railroad at Riderwood. (The TVR then connected the delightfully named Nannahubba with Silas 52 miles away.) And a year later the union was solemnized in the name of the Alabama, Tennessee & Northern Railroad Company.

Over the next 16 years the railroad reached toward Mobile over the former TVR line via Calvert, eventually arriving at Mobile in 1928 over its own rails,, and amassing a total of 214 main-line miles. (It never made it anywhere close to Tennessee, by the way.)

It was in this same year that the railroad ordered these three light decapods. Part of the flurry of purchases of the same design, mostly by southern roads, the engines offered a useful amount of tractive effort on a relatively light axle-loading. Piston valves measured 12" (306 mm) in diameter. Firebox heating surface area included 25 sq ft (2.3 sq m) of arch tubes.

All were sold by the AT & N in 1946. Georgia Car & Locomotive purchased 401 and sold it to Woodward Iron Company as their 41. WIC sold 41 to the Mid-Continent Railway Museum in 1964.

402 went on to serve the Gainesville Midland as 203 until 1959 when it was sold to the National Railway Historical Society.

403 traveled to the Durham & Southern in 1947 to join three younger sisters delivered to the North Carolina shortline in 1930 and 1933 (see Locobase 11370). Renumbered 203 in 1953, it was retired in 1954.

Frisco acquired the AT&N as a wholly owned subsidiary

Specifications by Steve Llanso of Sweat House Media
Class401
Locobase ID11,371
RailroadAlabama, Tennessee & Northern
CountryUSA
Whyte2-10-0
Number in Class3
Road Numbers401-403
GaugeStd
Number Built3
BuilderBaldwin
Year1928
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)19.67
Engine Wheelbase (ft)28.25
Ratio of driving wheelbase to overall engine wheebase 0.70
Overall Wheelbase (engine & tender) (ft)60.59
Axle Loading (Maximum Weight per Axle) (lbs)38,000
Weight on Drivers (lbs)190,000
Engine Weight (lbs)213,000
Tender Light Weight (lbs)137,500
Total Engine and Tender Weight (lbs)350,500
Tender Water Capacity (gals)7000
Tender Fuel Capacity (oil/coal) (gals/tons)10
Minimum weight of rail (calculated) (lb/yd)63
Geometry Relating to Tractive Effort
Driver Diameter (in)56
Boiler Pressure (psi)200
High Pressure Cylinders (dia x stroke) (in)24" x 28"
Tractive Effort (lbs)48,960
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.88
Heating Ability
Firebox Area (sq ft)197
Grate Area (sq ft)54.30
Evaporative Heating Surface (sq ft)2343
Superheating Surface (sq ft)553
Combined Heating Surface (sq ft)2896
Evaporative Heating Surface/Cylinder Volume159.81
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,860
Same as above plus superheater percentage12,923
Same as above but substitute firebox area for grate area46,886
Power L110,574
Power MT613.46

Photos


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