Toledo, Peoria, & Western 4-8-4 "Northern" Locomotives of the USA

The Toledo, Peoria & Western Railroad purchased six Class H-10 Northerns from the American Locomotive Company in 1937. These locomotives were given road numbers 80 through 85 and were the lightest 4-8-4 ever built for a North American railroad, weighing only 361,000 pounds. They had 69" drivers, 23.5 x 30 cylinders, a 250 psi boiler pressure and a tractive effort of 51,000 pounds.

Class Details by Steve Llanso of Sweat House Media

Class H-10 (Locobase 283)

In February 2006, Locobase put out a call for more information on this design on the Classic Trains forum and received diagrams from Ray Breyer, a Peoria-based modeller who had obtained several pages of TP & W diagrams. From the diagram and the accompanying roster, Locobase was able to complete the record. Works numbers were 68781-68786 in March 1937.

Don Ball called these the shyest Northerns he'd ever heard of. Certainly they were among the lightest of that wheel arrangement. They were obviously intended for freight work.

This design was remarkably small for a 4-8-4. Even the TP & W's own H-8/H-9 Consolidations (Locobase 7445) put more weight on the drivers. On the other hand, the firebox heating surface and superheat area were proportionally quite generous. Included in the direct heating surface were 15 sq ft of arch tubes and 89 sq ft of thermic syphons.

At the other end of their TP & W careers, all six H-10s are shown as going to Keystone in 1950 in the following order:

83 2/25

82 5/25

81 7/25

85 9/5

86 9/12

80 10/11

Specifications by Steve Llanso of Sweat House Media
Locobase ID283
RailroadToledo, Peoria, & Western
Number in Class6
Road Numbers80-85
Number Built6
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)18.25
Engine Wheelbase (ft)44.25
Ratio of driving wheelbase to overall engine wheebase 0.41
Overall Wheelbase (engine & tender) (ft)89.42
Axle Loading (Maximum Weight per Axle) (lbs)51,000
Weight on Drivers (lbs)204,000
Engine Weight (lbs)361,000
Tender Loaded Weight (lbs)324,000
Total Engine and Tender Weight (lbs)685,000
Tender Water Capacity (gals)18,000
Tender Fuel Capacity (oil/coal) (gals/tons)18
Minimum weight of rail (calculated) (lb/yd)85
Geometry Relating to Tractive Effort
Driver Diameter (in)69
Boiler Pressure (psi)250
High Pressure Cylinders (dia x stroke) (in)23.5" x 30"
Tractive Effort (lbs)51,023
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.00
Heating Ability
Firebox Area (sq ft)443
Grate Area (sq ft)77.30
Evaporative Heating Surface (sq ft)3961
Superheating Surface (sq ft)1096
Combined Heating Surface (sq ft)5057
Evaporative Heating Surface/Cylinder Volume263.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation19,325
Same as above plus superheater percentage23,577
Same as above but substitute firebox area for grate area135,115
Power L130,620
Power MT1323.64

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