Reading 2-4-2 "Columbian" Type Locomotives

Class M1-a/M1-b (Locobase 8879)

Data from Traite pratique de la machine locomotive ... By Maurice Demoulin, 1898

Librairie polytechnique, Baudry et Cie, p 380. Baldwin works #12433, 12672, 12676, 12679-80, 13370, 13408-09, 13411-13413. Additional data from 1907 Catalogue of Mechanical Engineering Collection in the Science Division of the Victoria & Albert Museum (Board of Education South Kensington)., pp 92.

As unusual as the adoption of the Bicycle wheel arrangement was in the US, production of 10 Bicycles with the 4-cylinder Vauclain compound layout was rarer still. They didn't persist in this arrangement for long. One (682) was rebuilt as an Atlantic in May 1899, the others as N-4a camelback Moguls in 1904.

Even then, 5 were scrapped within a few years, while 4 underwent a further transformation as L-6a class 4-6-0s. In only one instance did an engine survive past 1911: 682 (now 315) was rebuilt again as a 4-6-0 (class L-6b) and operated until 1927.

Specifications
ClassM1-a/M1-b
Locobase ID8879
RailroadReading
Whyte2-4-2
Road Numbers618-622, 679-684
GaugeStd
BuilderBurnham, Williams & Co
Year1892
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase 7.50'
Engine Wheelbase23.25'
Ratio of driving wheelbase to overall engine wheebase 0.32
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers84023 lbs
Engine Weight131748 lbs
Tender Light Weight92000 lbs
Total Engine and Tender Weight223748 lbs
Tender Water Capacity4755 gals
Tender Fuel Capacity (oil/coal)5.5 tons
Minimum weight per yard of rail on which locomotive could run70 lb rail
Geometry Relating to Tractive Effort
Driver Diameter78"
Boiler Pressure180 psi
Cylinders (dia x stroke)13" x 26"
Low Pressure Cylinders (dia x stroke)22" x 26"
Tractive Effort12777 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.58
Heating Ability
Firebox Area173.46 sq. ft
Grate Area76 sq. ft
Evaporative Heating Surface1435
Superheating Surface
Combined Heating Surface1435
Evaporative Heating Surface/Cylinder Volume359.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13680
Same as above plus superheater percentage13680
Same as above but substitute firebox area for grate area31223
Power L14710
Power MT247.16

Credits

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