Minneapolis & St Louis 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class M1/M1-46 (Locobase 1416)

Data from table in May 1916 issue of Railway Mechanical Engineer (RME). See also M&StL Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Several Alco facilities supplied engines with Schenectady producing works numbers 54985-54999 in February 1915..

These were relatively lightweight Mikes that nevertheless gave many years of service to the M&StL All 35 had the same power dimensions, 14" (356 mm) piston valves, identical heating surface areas, and wheelbases.

The changes between the first 20 and the later 15 were relatively minor. In the first 20, reverse gear was supplied by Ragonnet, Alco built the engine's trailing truck, and the tender rode on arch-bar trucks.

When they were rebuilt by Lucius Sprague in the late 1930s, two even received stainless steel boiler jackets, and valences under the running boards. By the end, some had been fitted with thermic syphons and feedwater heaters.


Class M1/M1-46 (Locobase 16216)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Stephen Low for his 16 July 2016 email reporting the higher boiler pressure settings.) Works numbers were 62562-62576 in January 1921.

These were relatively lightweight Mikes that nevertheless gave many years of service to the M&StL All 35 had the same power dimensions, 14" (356 mm) piston valves, identical heating surface areas, and wheelbases.

The changes between the first 20 and the later 15 were relatively minor. The 1921 engines used Alco's reverse gear, Commonwealth's trailing truck, and the tender trucks were equalized. Adhesion weight increaseed rose by 7,300 lb (3,311 kg) to 196,500 lb (89,131 kg).

When they were rebuilt by Lucius Sprague in the late 1930s, two even received stainless steel boiler jackets, and valences under the running boards. By the end, some had been fitted with thermic syphons and feedwater heaters.

Specifications by Steve Llanso of Sweat House Media
ClassM1/M1-46M1/M1-46
Locobase ID1416 16,216
RailroadMinneapolis & St Louis (MSL)Minneapolis & St Louis (MSL)
CountryUSAUSA
Whyte2-8-22-8-2
Number in Class2015
Road Numbers600-619620-634
GaugeStdStd
Number Built2015
BuilderAlco-SchenectadyAlco-Brooks
Year19151921
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.75 / 4.8015.75 / 4.80
Engine Wheelbase (ft / m)33.58 / 10.2433.58 / 10.24
Ratio of driving wheelbase to overall engine wheebase 0.47 0.47
Overall Wheelbase (engine & tender) (ft / m)63.56 / 19.3763.50 / 19.35
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)189,500 / 85,956186,500 / 84,595
Engine Weight (lbs / kg)259,900 / 117,889252,500 / 114,532
Tender Loaded Weight (lbs / kg)156,000 / 70,760165,500 / 75,070
Total Engine and Tender Weight (lbs / kg)415,900 / 188,649418,000 / 189,602
Tender Water Capacity (gals / ML)10,200 / 38.648500 / 32.20
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)17.50 / 15.9011.75 / 10.70
Minimum weight of rail (calculated) (lb/yd / kg/m)79 / 39.5078 / 39
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)59 / 149959 / 1499
Boiler Pressure (psi / kPa)185 / 12.80200 / 12.80
High Pressure Cylinders (dia x stroke) (in / mm)24" x 30" / 610x76224" x 30" / 610x762
Tractive Effort (lbs / kg)46,056 / 20890.6849,790 / 22584.39
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.11 3.75
Heating Ability
Firebox Area (sq ft / m2)231 / 21.46231 / 21.46
Grate Area (sq ft / m2)55 / 5.1155 / 5.11
Evaporative Heating Surface (sq ft / m2)2995 / 278.242995 / 278.24
Superheating Surface (sq ft / m2)706 / 65.59706 / 65.59
Combined Heating Surface (sq ft / m2)3701 / 343.833701 / 343.83
Evaporative Heating Surface/Cylinder Volume190.67190.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,17511,000
Same as above plus superheater percentage12,10813,090
Same as above but substitute firebox area for grate area50,85554,978
Power L112,16513,151
Power MT566.10621.83