Wabash 2-6-2 "Prairie" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class G1 - 64"" (Locobase 6933)

Railroad Age Gazette (17 July 1908) reported that these locomotives were fast freight Prairies virtually identical to those in service on the CB&Q. Unlike the first 60 (Locobase 6932), these had 64" drivers, which meant they weren't intended for some of the higher-end freight traffic served by the 70" engines. Like those locomotives, this batch was superheated later on.

See also data from WAB 1 - 1907 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.


Class G1 - 70"" (Locobase 4202)

Railroad Age Gazette (17 July 1908) reported that these locomotives were fast freight Prairies virtually identical to those in service on the CB&Q; the latter had 69" drivers. (Drury - 1993 - says the whole class had 64" drivers, but the first 60, which included the batch described by RAG, had 70" wheels.) Earlier engines in the class had gone into service in 1907.

They were reported to have a train load capacity of 1,750-2,100 tons on lines with grades between 0.5-0.85%. RAG noted several features about the design, in particular the trend toward the use of flexible staybolts in great numbers and the provision of leading truck wheels 37 1/2" in diameter.

Of the 90 G-1s, 23 became J-2 Pacifics beginning in 1916. Retirements of the Prairies began in 1934 and ended in 1950.

See also data from WAB 1 - 1907 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.


Class G1s - 64"" (Locobase 6934)

Data from WAB 1 - 1907 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

This batch was identical to the earlier G-1s, but had smaller drivers. Like the others, these were superheated beginning in the teens, 3 having been ministered to by January 1917. By the end of the 1920s, all had been superheated. The result is a nicely balanced design in Locobase's opinion. The heat generator wasn't overworked and if the max axle loading was a bit high -- well, these were mainline engines.


Class G1s - 70"" (Locobase 6932)

Data from WAB 1 - 1907 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

The Wabash's lone Prairie ...(Locobase is unapologetic). Not long after the G-1s went into service, railroads became convinced of the value of superheating. In the Wabash's case, they leaped at the chance to apply it to their 2-6-2s. By January 1917 three had already been made over. By the late 1920s 37 of the original 60 had been redone.

The last batch of 30 supplied by Alco in 1907, which had 64" drivers, were also superheated; see Locobase 6933.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassG1 - 64""G1 - 70""G1s - 64""G1s - 70""
Locobase ID6933 4202 6934 6932
RailroadWabashWabashWabashWabash
CountryUSAUSAUSAUSA
Whyte2-6-22-6-22-6-22-6-2
Number in Class30603737
Road Numbers2061-20902001-206020012001
GaugeStdStdStdStd
Number Built3060
BuilderAlco-RogersseveralWabashWabash
Year1907190619171917
Valve GearWalschaertWalschaertStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.37 / 4.0813.37 / 4.0813.37 / 4.0813.37 / 4.08
Engine Wheelbase (ft / m)30.71 / 9.3630.71 / 9.3630.71 / 9.3630.71 / 9.36
Ratio of driving wheelbase to overall engine wheebase 0.44 0.44 0.44 0.44
Overall Wheelbase (engine & tender) (ft / m)63.35 / 19.3163.35 / 19.3161.35 / 18.7061.35 / 18.70
Axle Loading (Maximum Weight per Axle) (lbs / kg)62,650 / 28,41862,650 / 28,418
Weight on Drivers (lbs / kg)143,100 / 64,909143,100 / 64,909167,900 / 76,158167,900 / 76,158
Engine Weight (lbs / kg)203,100 / 92,125203,100 / 92,125230,100 / 104,372230,100 / 104,372
Tender Loaded Weight (lbs / kg)155,317 / 70,451155,317 / 70,451153,000 / 69,400153,000 / 69,400
Total Engine and Tender Weight (lbs / kg)358,417 / 162,576358,417 / 162,576383,100 / 173,772383,100 / 173,772
Tender Water Capacity (gals / ML)7700 / 29.177700 / 29.176000 / 22.736000 / 22.73
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)15 / 13.6015 / 13.6010 / 9.1010 / 9.10
Minimum weight of rail (calculated) (lb/yd / kg/m)80 / 4080 / 4093 / 46.5093 / 46.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)64 / 162670 / 177864 / 162670 / 1778
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80210 / 14.50210 / 14.50
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x71122" x 28" / 559x71123" x 28" / 584x71123" x 28" / 584x711
Tractive Effort (lbs / kg)35,998 / 16328.4432,912 / 14928.6541,312 / 18738.8337,771 / 17132.66
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.98 4.35 4.06 4.45
Heating Ability
Firebox Area (sq ft / m2)190.50 / 17.70190.50 / 17.70218 / 20.26218 / 20.26
Grate Area (sq ft / m2)54.25 / 5.0454.25 / 5.0454.25 / 5.0454.25 / 5.04
Evaporative Heating Surface (sq ft / m2)3559 / 330.763559 / 330.762805 / 260.692805 / 260.69
Superheating Surface (sq ft / m2)613 / 56.97613 / 56.97
Combined Heating Surface (sq ft / m2)3559 / 330.763559 / 330.763418 / 317.663418 / 317.66
Evaporative Heating Surface/Cylinder Volume288.90288.90208.33208.33
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,85010,85011,39311,393
Same as above plus superheater percentage10,85010,85013,44313,443
Same as above but substitute firebox area for grate area38,10038,10054,02054,020
Power L17813854515,65817,126
Power MT361.10394.94616.79674.62

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