Western Maryland 2-6-6-2 Type Locomotives

Class M-1 (Locobase 8321)

Data from WM MISC steam locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

Comparisons with other 2-6-6-2s reveals that this design was virtually identical to that of the Great Northern's second batch of L-1s (Locobase 819), but with larger HP cylinders.

Like the later Ls, these articulateds were dedicated to pusher service, which explains the lack of a superheater upgrade and the retention of slide valves. According to Drury (1993), the class was converted to super-switchers (0-6-6-0s) in 1927-1931.

Specifications
ClassM-1
Locobase ID8321
RailroadWestern Maryland (WM)
Whyte2-6-6-2
Road Numbers951-959
GaugeStd
BuilderBaldwin
Year1910
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase10'
Engine Wheelbase44.83'
Ratio of driving wheelbase to overall engine wheebase 0.22
Overall Wheelbase (engine & tender)78.44'
Axle Loading (Maximum Weight per Axle)56800 lbs
Weight on Drivers298100 lbs
Engine Weight342000 lbs
Tender Light Weight166200 lbs
Total Engine and Tender Weight508200 lbs
Tender Water Capacity9500 gals
Tender Fuel Capacity (oil/coal)14 tons
Minimum weight per yard of rail on which locomotive could run82.81 lb rail
Geometry Relating to Tractive Effort
Driver Diameter55"
Boiler Pressure200 psi
Cylinders (dia x stroke)23" x 32"
Low Pressure Cylinders (dia x stroke)35" x 32"
Tractive Effort73085 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.08
Heating Ability
Firebox Area225 sq. ft
Grate Area78 sq. ft
Evaporative Heating Surface5609
Superheating Surface
Combined Heating Surface5609
Evaporative Heating Surface/Cylinder Volume364.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15600
Same as above plus superheater percentage15600
Same as above but substitute firebox area for grate area45000
Power L13464.59
Power MT153.74

Credits

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