Toledo, Peoria, & Western 4-8-4 "Northern" Type Locomotives

Introduction

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

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
ClassH-10
Locobase ID283
RailroadToledo, Peoria, & Western
CountryUSA
Whyte4-8-4
Road Numbers80-85
GaugeStd
BuilderAlco-Schenectady
Year1937
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase18.25'
Engine Wheelbase44.25'
Ratio of driving wheelbase to overall engine wheebase 0.41
Overall Wheelbase (engine & tender)89.42'
Axle Loading (Maximum Weight per Axle)51000 lbs
Weight on Drivers204000 lbs
Engine Weight361000 lbs
Tender Light Weight324000 lbs
Total Engine and Tender Weight685000 lbs
Tender Water Capacity18000 gals
Tender Fuel Capacity (oil/coal)18 tons
Minimum weight of rail (calculated) on which locomotive could run85 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter69"
Boiler Pressure250 psi
Cylinders (dia x stroke)23.5" x 30"
Tractive Effort51023 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.00
Heating Ability
Firebox Area443 sq. ft
Grate Area77.30 sq. ft
Evaporative Heating Surface3961 sq. ft
Superheating Surface1096 sq. ft
Combined Heating Surface5057 sq. ft
Evaporative Heating Surface/Cylinder Volume263.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation19325
Same as above plus superheater percentage23577
Same as above but substitute firebox area for grate area135115
Power L130620
Power MT1323.64

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.