Duluth Missabe & Northern / Duluth & Iron Range 4-6-2 "Pacific" Type Locomotives

Class A (Locobase 7283)

See data from DM&IR 6 -1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Northern Minnesota didn't have much call for passenger service, but the Iron Range found a need for more power than the Ten-wheelers could provide. They bought these small Pacifics that possessed a free-steaming boiler and 14" piston valves. Locobase doesn't know if the quartet was delivered with superheaters, but if not, the railroad installed them before too long.

All four engines served the D & IR, the DM & N, and the DM & IR on the same rails for 40 years; retirements came in 1953-1955.

See the larger DM & N Pacifics delivered by Baldwin in the same year in Locobase 7284.

Class P (Locobase 7284)

See data from DM&IR 6 -1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

In the same time the Duluth & Iron Range took delivery of four light Pacifics (Locobase 7283), the same builder supplied these substantially larger engines to the DM & N. Whereas the Iron Range's engines were branch-liners, the Northern's trio were headed to the main line. Free-steaming and fitted with 15" piston valves, these 4-6-2s served the DM & N and successor DM & IR into the 1950s before retiring in 1955 (401) and 1958 (402).

Specifications
ClassAP
Locobase ID72837284
RailroadDuluth & Iron Range (DM&IR)Duluth Missabe & Northern (DM&IR)
Whyte4-6-24-6-2
Road Numbers107-110 / 1107-1110400-402
GaugeStdStd
BuilderBaldwinBaldwin
Year19131913
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase12.50'12.50'
Engine Wheelbase31.83'35'
Ratio of driving wheelbase to overall engine wheebase 0.39 0.36
Overall Wheelbase (engine & tender)63.04'65.83'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers140000 lbs173310 lbs
Engine Weight223900 lbs254600 lbs
Tender Light Weight137400 lbs171800 lbs
Total Engine and Tender Weight361300 lbs426400 lbs
Tender Water Capacity6300 gals8600 gals
Tender Fuel Capacity (oil/coal)14 tons14 tons
Minimum weight per yard of rail on which locomotive could run77.78 lb rail96.28 lb rail
Geometry Relating to Tractive Effort
Driver Diameter69"69"
Boiler Pressure200 psi200 psi
Cylinders (dia x stroke)22" x 28"25" x 28"
Tractive Effort33389 lbs43116 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.19 4.02
Heating Ability
Firebox Area205 sq. ft243.10 sq. ft
Grate Area47.70 sq. ft58.60 sq. ft
Evaporative Heating Surface27163087
Superheating Surface610906
Combined Heating Surface33263993
Evaporative Heating Surface/Cylinder Volume220.47194.05
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation954011720
Same as above plus superheater percentage11289.6714379.23
Same as above but substitute firebox area for grate area48519.5459651.74
Power L117234.4418009.83
Power MT814.19687.29

Reference

Credits

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