0-10-0 Steam Locomotives in the USA

Duluth, Missabe & Northern


Class Details by Steve Llanso of Sweat House Media

Class S-6 (Locobase 12635)

Data from DeGolyer, Volume 77, pp. 766+. See also DM&IR 1 1951 Locomotive Diagram book supplied in May 2005 by Allen Stanley. (NB: For a detailed view of the component manufacturers that might be called on to supply a locomotive's needs in 1927, see pp. 768 of the specifications.) (Thanks to Michael Stary for his 28 October 2020 email catching the inconsistency between road numbers and total built and to Chris Hohl for his 30 June 2021 email noting the correct value for the tender booster.) Works numbers were 60213 in September 1927, 60263 in November, and 60293-60294 in December.

Making up loaded iron-ore cars called for motive power as big as the enormous articulateds that hauled them to the ports. Baldwin delivered these biggest-in-class, all-adhesion switchers with Franklin tender boosters to add to their already sizable tractive effort.

Apparently the DM&N quickly concluded that the boosters were an unnecessary adjunct. Before the DM&N was rolled into the Duluth, Missabe & Iron Range in 1930, the railroad had removed them.

The S-6 bar frames used a Commonwealth cast steel bed that included a cast steel cylinder saddle as well as front and rear bumpers. (The cylinders themselves were made of cast iron.) The fireman had help from a Standard Steel Company Simplex Type B stoker.

The firebox's heating surface area included its two thermic syphons (80 sq ft/7.4 sq m) and four arch tubes (28 sq ft/2.6 sq m).

Piston valves measured 14" (356 mm) in diameter and the specifications stated that the Baker valve motion was to be arranged for "long travel valves" and be able to be set for a maximum of 65% cut-off.

The "Ore Sorter" quartet served the DM & IR until the end of steam in the mid-1950s.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassS-6
Locobase ID12635
RailroadDuluth, Missabe & Northern (DM&IR)
CountryUSA
Whyte0-10-0
Number in Class4
Road Numbers90-93
GaugeStd
Number Built4
BuilderBaldwin
Year1927
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)20.83 / 6.35
Engine Wheelbase (ft / m)20.83 / 6.35
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m)66 / 20.12
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)352,250 / 159,778
Engine Weight (lbs / kg)352,350 / 159,823
Tender Loaded Weight (lbs / kg)186,450 / 84,572
Total Engine and Tender Weight (lbs / kg)538,800 / 244,395
Tender Water Capacity (gals / ML)10,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)14 / 13
Minimum weight of rail (calculated) (lb/yd / kg/m)117 / 58.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 1448
Boiler Pressure (psi / kPa)245 / 1690
High Pressure Cylinders (dia x stroke) (in / mm)28" x 30" / 711x762
Tractive Effort (lbs / kg)85,931 / 38977.69
Booster (lbs)14,500
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.10
Heating Ability
Tubes (number - dia) (in / mm)214 - 2.25" / 57
Flues (number - dia) (in / mm)53 - 5.5" / 140
Flue/Tube length (ft / m)19 / 5.79
Firebox Area (sq ft / m2)329.50 / 30.61
Grate Area (sq ft / m2)80 / 7.43
Evaporative Heating Surface (sq ft / m2)4175 / 387.87
Superheating Surface (sq ft / m2)1170 / 108.70
Combined Heating Surface (sq ft / m2)5345 / 496.57
Evaporative Heating Surface/Cylinder Volume195.28
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation19,600
Same as above plus superheater percentage23,912
Same as above but substitute firebox area for grate area98,488
Power L117,802
Power MT557.09

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