Atchison, Topeka & Santa Fe 2-8-8-0 "Consolidation Mallet" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 3296 (Locobase 436)

Data from AT&SF 7 -1920 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Information about how many, when, and by whom this class was supplied from [] (also visited 6 Feb 2006), the Santa Fe All-Time Steam Roster maintained by Evan Werkema.

Known to the Santa Fe as a "Consolidation Mallet," these two engines were rebuilt from 2-8-0s at Topeka in 1911. Like other Santa Fe mallets, this class has an additional 2,383 sq ft (221.83 sq m) ahead of the tube sheets as reheater space. Its grate area, on the other hand, was almost laughably small and was worked very hard. Another oddity was the weight distribution. On the front engine only the front driven axle carried as much as 50,000 lb (56,000 lb, actually) while the other three all bore 35,000-37,000 lb. The rear engine had a little more balance, but the axle loadings still varied from 42,500 lb (rearmost) to 54,000 lb (1st and 3rd).

The first engine -- 3296 -- later had its HP cylinders bushed to 22 inches (possibly because its maintainers could no longer get the original 24-in diameter true enough during reboring). Tractive effort rating dropped to 76,750 lb.

Restored to 2-8-0 arrangement in 1923.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID436
RailroadAtchison, Topeka & Santa Fe (ATSF)
Number in Class4
Road Numbers3296-3299
Number Built4
BuilderSanta Fe
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)31 / 9.45
Engine Wheelbase (ft / m)51 / 15.54
Ratio of driving wheelbase to overall engine wheelbase 0.61
Overall Wheelbase (engine & tender) (ft / m)94.48 / 28.80
Axle Loading (Maximum Weight per Axle) (lbs / kg)56,000 / 25,401
Weight on Drivers (lbs / kg)366,500 / 166,242
Engine Weight (lbs / kg)391,500 / 177,582
Tender Loaded Weight (lbs / kg)234,460 / 106,349
Total Engine and Tender Weight (lbs / kg)625,960 / 283,931
Tender Water Capacity (gals / ML)12,000 / 45.45
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)4000 / 15,140
Minimum weight of rail (calculated) (lb/yd / kg/m)76 / 38
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 1448
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)24" x 32" / 610x813
Low Pressure Cylinders (dia x stroke) (in / mm)38" x 32" / 965x813
Tractive Effort (lbs / kg)78,595 / 35650.13
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.66
Heating Ability
Tubes (number - dia) (in / mm)355 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)15 / 4.57
Firebox Area (sq ft / m2)157 / 14.59
Grate Area (sq ft / m2)47.40 / 4.41
Evaporative Heating Surface (sq ft / m2)2930 / 272.30
Superheating Surface (sq ft / m2)1922 / 178.62
Combined Heating Surface (sq ft / m2)4852 / 450.92
Evaporative Heating Surface/Cylinder Volume174.87
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9480
Same as above plus superheater percentage13,272
Same as above but substitute firebox area for grate area43,960
Power L19505
Power MT457.41

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Wes Barris