Chesapeake & Ohio 4-8-2 "Mountain" Type Locomotives

Class J-1 (Locobase 198)

Data from C&O 9-1936 and C&O 12-1946 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive collection. The firebox heating surface included 28 sq ft of arch tubes.

These are considered to be the first of the Mountain type, originally built for the C&O to handle 700 tons over the Clifton Forge Division in the Allegheny Mountains. The 540's number was 318 at first.

Eugene L Huddleston, writing in the November 2000 issue of the Chesapeake & Ohio Historical Magazine ("C&O's J-1 & K-1"), notes that the J-1s could hit the desired speeds with a heavy train (10 cars). Yet, the design had "ridiculously low drivers" and " extremely long main rods." In addition to the high rpm of such small drivers at high speeds, driving the set on the third axle increased the dynamic augment and hence the stress on the tracks. (Most Mountains, says Huddleston, were driven on the second axle.) A late-1920s solution involved lengthening the piston rod and supporting the longer Alligator crosshead guide with a second yoke.

That the design had power was undeniable -- combustion chamber, superheater, huge boiler, automatic smoker. The trio enjoyed a long career on the two mountain divisions on which they ran because the large boiler meant plenty of steam and the low drivers were less of a liability.

Class J-2 (Locobase 1420)

Firebox heating surface included 99 sq ft of thermic syphons. Boiler had feedwater heater.

USRA heavy Mountain. Only 15 "Heavy" mountains entered service under the USRA, of which 5 (Baldwin 2, Alco-Brooks 3) went to the Chesapeake and Ohio. Richmond delivered two more sisters in 1923.

Specifications
ClassJ-1J-2
Locobase ID1981420
RailroadChesapeake & Ohio (C & O)Chesapeake & Ohio (C & O)
Whyte4-8-24-8-2
Road Numbers540-542543-549
GaugeStdStd
BuilderAlco-RichmondSeveral
Year19111918
Valve GearWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase16.50'18.25'
Engine Wheelbase37.42'40'
Ratio of driving wheelbase to overall engine wheebase 0.44 0.46
Overall Wheelbase (engine & tender)76.11'75.70'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers238000 lbs246850 lbs
Engine Weight330000 lbs363550 lbs
Tender Light Weight219100 lbs300000 lbs
Total Engine and Tender Weight549100 lbs663550 lbs
Tender Water Capacity12000 gals16000 gals
Tender Fuel Capacity (oil/coal)15 tons2016 gals
Minimum weight per yard of rail on which locomotive could run99.17 lb rail102.85 lb rail
Geometry Relating to Tractive Effort
Driver Diameter62"69"
Boiler Pressure180 psi200 psi
Cylinders (dia x stroke)29" x 28"28" x 30"
Tractive Effort58110 lbs57948 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.10 4.26
Heating Ability
Firebox Area338 sq. ft438 sq. ft
Grate Area66.50 sq. ft76.20 sq. ft
Evaporative Heating Surface41084727
Superheating Surface8501085
Combined Heating Surface49585812
Evaporative Heating Surface/Cylinder Volume191.91221.09
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1197015240
Same as above plus superheater percentage14022.1418085.04
Same as above but substitute firebox area for grate area71270.42103953.41
Power L111685.3217945.79
Power MT432.97641.10

Reference

Credits

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