Wabash 4-6-2 "Pacific" Locomotives of the USA

The Wabash Railroad bought 16 "Pacific" type locomotives in 1912. Ten were built by the Richmond Works of ALCO and were delivered in February and assigned road numbers 660 through 669. Another six were built by the Baldwin Locomotive Works and were delivered in May and assigned road numbers 670 through 675. These were the last new passenger locomotives the Wabash would buy. Beginning in 1916 and continuing through 1926, the Wabash converted some of its 2-6-2 "Prairie" Type locomotives into "Pacifics". These Class G-1 locomotives had 70" drivers, 23x28 cylinders, 215 psi boiler pressure and a tractive effort of 38,670 lbs. In all 23 were converted with six, numbered 1676 through 1681, put in service between Windsor, ON and Buffalo, NY. The remaining seventeen were assigned road numbers 683 through 699 and went into service in the United States.

Roster by Richard Duley

Road NumberEx Class G-1Date RebuiltDate Scrapped

Class Details by Steve Llanso of Sweat House Media

Class J1 (Locobase 6936)

Data from WAB 1 - 1917 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

These were the last new passenger locomotives bought by the Wabash and were among the last Pacifics to be delivered as saturated-steam engines. Alco-Richmond delivered the first 10 and Baldwin the last 5. Specs for the latter group dictated that the locomotives were to be built "...from American Locomotive Co prints. No changes to be made without approval of the Ry. Co."

See Locobase 6937 for their superheated modifications.

Class J1s (Locobase 6937)

Data from WAB 1 - 1917 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

When the Wabash superheated its only store-bought Pacifics (Locobase 6936), it was following an irresistible trend. The result was a relatively light-on-the-drivers 4-6-2 with enough heating surface to be in the middle of the pack and a grate somewhat larger than the average. All in all, a typical Wabash design. And like the other Wabash steam locomotives, run until the end of steam.

Class J2 (Locobase 6935)

Data from WAB 1 - 1917 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Taking a Prairie (Locobase 4202) and stretching it almost 4 feet into a Pacific was not a common way to build a passenger engine, but the Wabash thought it worthwhile enough to do so almost 2 dozen times. In effect, the middle of the boiler remained intact while a couple of feet were added to the wheelbases ahead and behind the driver set. In the process, the 2 1/4" tubes were taken out in favor of more and longer 2" tubes and 30 superheater flues went in the boiler as well.

Like the other Wabash classes, these locomotives had long lives. A curious point about the broken number series: The six 1600 engines ran between Windsor, Ontario and Buffalo, New York; the others operated in the US. All survived past World War II and most saw steam out on the railroad.

Specifications by Steve Llanso of Sweat House Media
Locobase ID6936 6937 6935
Number in Class161623
Road Numbers660-675660-675683-699, 1676-1681
Number Built16
Valve GearStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)12.8312.8313.37
Engine Wheelbase (ft)343434.35
Ratio of driving wheelbase to overall engine wheebase 0.38 0.38 0.39
Overall Wheelbase (engine & tender) (ft)66.1766.1764.65
Axle Loading (Maximum Weight per Axle) (lbs)52,00053,71452,900
Weight on Drivers (lbs)150,000155,140151,400
Engine Weight (lbs)241,000248,840241,000
Tender Loaded Weight (lbs)157,000157,000153,000
Total Engine and Tender Weight (lbs)398,000405,840394,000
Tender Water Capacity (gals)800080006000
Tender Fuel Capacity (oil/coal) (gals/tons)131310
Minimum weight of rail (calculated) (lb/yd)838684
Geometry Relating to Tractive Effort
Driver Diameter (in)747470
Boiler Pressure (psi)200200200
High Pressure Cylinders (dia x stroke) (in)24" x 26"24" x 26"22.5" x 28"
Tractive Effort (lbs)34,40434,40434,425
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.36 4.51 4.40
Heating Ability
Firebox Area (sq ft)206206218
Grate Area (sq ft)636354.25
Evaporative Heating Surface (sq ft)437933103165
Superheating Surface (sq ft)740740
Combined Heating Surface (sq ft)437940503905
Evaporative Heating Surface/Cylinder Volume321.66243.14245.63
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12,60012,60010,850
Same as above plus superheater percentage12,60014,86812,912
Same as above but substitute firebox area for grate area41,20048,61651,884
Power L1980119,93119,765
Power MT432.15849.69863.43


If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.