In 1943, 15 more Northerns (road numbers 2201 through 2215) were delivered from the Baldwin Locomotive Works. These "war babies" were duplicates of the 1938 D&RGW 4-8-4s and had 73" drivers, 26 x 30 cylinders, a boiler pressure of 285 psi, a weight of 496,000 lbs and a tractive effort of 67,200 pounds.
There are no survivors.
|Qty.||Road Numbers||Year Built||Builder|
Rebuilt 2-8-4s (Locobase 1371) that became very successful freight engines whose tall drivers turned on roller bearings. Feed water heater was the Worthington 4 1/4 BL-2. The firebox heating surface area includes the combustion chamber, 113 sq ft (10.5 sq m) in two thermic syphons (one in the combustion chamber, one in the firebox proper), and 15 sq ft (1.4 sq m) of arch tubes.
See http://www.steamlocomotive.com/northern/mp.html (visited 7 Jan 2003), where Wes Barris says they had cast-steel beds and roller bearings.
Firebox heating surface included 136 sq ft (12.6 sq m) of thermic syphons installed in the firebox itself and the combustion chamber. These freight engines were based on the Denver and Rio Grande Western's 1800-class 4-8-4s, with a little Northern Pacific A-5 blended in. Compared to the 2100-class rebuilds (Locobase 1371) of 1940-1942, these Northerns had smaller drivers and less cylinder volume, but a higher boiler pressure setting. Their axles turned on Timken roller bearings and, like the 2100s, 14" (356 mm) piston valves supplied the cylinders. Feed water was heated by a Worthington 6 - 5A.
The last of the class was scrapped in 1956.
Another 4-8-4 class on the MP's roster were the 2101-2125, which were rebuilds from 63-in DD 2-8-4 Berkshires to 75-in driver 4-8-4s. (See Locobase 1372).
|Specifications by Steve Llanso of Sweat House Media|
|Class||2101/N-75 Victory Locomotives||N-73|
|Railroad||Missouri Pacific (MP)||Missouri Pacific (MP)|
|Number in Class||25||15|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||19.50||19.25|
|Engine Wheelbase (ft)||45.17||47.08|
|Ratio of driving wheelbase to overall engine wheebase||0.43||0.41|
|Overall Wheelbase (engine & tender) (ft)||89.81||93.48|
|Axle Loading (Maximum Weight per Axle) (lbs)|
|Weight on Drivers (lbs)||279,300||279,400|
|Engine Weight (lbs)||445,950||489,000|
|Tender Loaded Weight (lbs)||287,700|
|Total Engine and Tender Weight (lbs)||776,700|
|Tender Water Capacity (gals)||17,250||19,350|
|Tender Fuel Capacity (oil/coal) (gals/tons)||20||20|
|Minimum weight of rail (calculated) (lb/yd)||116||116|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||75||73|
|Boiler Pressure (psi)||250||285|
|High Pressure Cylinders (dia x stroke) (in)||28" x 30"||26" x 30"|
|Tractive Effort (lbs)||66,640||67,299|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.19||4.15|
|Firebox Area (sq ft)||484||559|
|Grate Area (sq ft)||88.30||106|
|Evaporative Heating Surface (sq ft)||4839||5306|
|Superheating Surface (sq ft)||1938||2200|
|Combined Heating Surface (sq ft)||6777||7506|
|Evaporative Heating Surface/Cylinder Volume||226.33||287.82|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||22,075||30,210|
|Same as above plus superheater percentage||28,477||38,971|
|Same as above but substitute firebox area for grate area||156,090||205,516|