Pennsylvania 2-8-8-2 "Chesapeake" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class HH1s (Locobase 325)

Data from Wiener (1930).

A unique engine on the Pennsy, a simple-expansion articulated built at a time when all other articulateds were Mallet compounds. In a departure from Pennsylvania practice, this engine used a wagon-top boiler with the longest tubes of any engine in Locobase. A further departure was the builder--Alco didn't send many engines to the Pennsy. Note the low boiler pressure.

3396 operated in pusher service until 1928.

Specifications by Steve Llanso of Sweat House Media
Locobase ID325
RailroadPennsylvania (PRR)
Number in Class1
Road Numbers3396
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)41.83
Engine Wheelbase (ft)57.41
Ratio of driving wheelbase to overall engine wheebase 0.73
Overall Wheelbase (engine & tender) (ft)88.09
Axle Loading (Maximum Weight per Axle) (lbs)63,000
Weight on Drivers (lbs)437,500
Engine Weight (lbs)482,500
Tender Loaded Weight (lbs)186,400
Total Engine and Tender Weight (lbs)668,900
Tender Water Capacity (gals)9000
Tender Fuel Capacity (oil/coal) (gals/tons)30
Minimum weight of rail (calculated) (lb/yd)91
Geometry Relating to Tractive Effort
Driver Diameter (in)56
Boiler Pressure (psi)160
High Pressure Cylinders (dia x stroke) (in)27" x 28" (4)
Tractive Effort (lbs)99,144
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.41
Heating Ability
Firebox Area (sq ft)405.05
Grate Area (sq ft)96.55
Evaporative Heating Surface (sq ft)6125
Superheating Surface (sq ft)1257
Combined Heating Surface (sq ft)7382
Evaporative Heating Surface/Cylinder Volume165.05
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,448
Same as above plus superheater percentage18,074
Same as above but substitute firebox area for grate area75,825
Power L17832
Power MT315.73


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