Bangor & Aroostook 4-8-2 "Mountain" Type Locomotives

Class M (Locobase 192)

Data from tables in 1930 Locomotive Cyclopedia and BAR 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Firebox had thermic syphons. Relatively small Mountain types with small drivers for low-speed freight hauling. Originally listed weight on the drivers came to 204,000 lb. All 10 had the same boiler and firebox. Somehow the BAR managed to apply 7 different classifications to them.

7 delivered in 1929-1930, 2 more in 1935, and one more in 1945.

Specifications
ClassM
Locobase ID192
RailroadBangor & Aroostook
Whyte4-8-2
Road Numbers100-109
GaugeStd
BuilderAlco-Schenectady
Year1929
Valve Gear
Locomotive Length and Weight
Driver Wheelbase16.50'
Engine Wheelbase38.08'
Ratio of driving wheelbase to overall engine wheebase 0.43
Overall Wheelbase (engine & tender)73.67'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers213360 lbs
Engine Weight317490 lbs
Tender Light Weight232000 lbs
Total Engine and Tender Weight549490 lbs
Tender Water Capacity10000 gals
Tender Fuel Capacity (oil/coal)15 tons
Minimum weight per yard of rail on which locomotive could run88.90 lb rail
Geometry Relating to Tractive Effort
Driver Diameter62"
Boiler Pressure240 psi
Cylinders (dia x stroke)22.5" x 30"
Tractive Effort49972 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.27
Heating Ability
Firebox Area351 sq. ft
Grate Area65.60 sq. ft
Evaporative Heating Surface3583
Superheating Surface932
Combined Heating Surface4515
Evaporative Heating Surface/Cylinder Volume259.53
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15744
Same as above plus superheater percentage18993.92
Same as above but substitute firebox area for grate area101629.08
Power L124656.60
Power MT1019.09

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.