Pennsylvania 2-4-6 Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Old L (Locobase 5489)

Data from (Viewed 11 April 2003).

According to William Edson's exhaustive compilation, this locomotive only operated for about 11 years and was scrapped in October 1893. The arrangement looks very much like a Mason Bogie suburban tank engine. 2-4-6Ts (56-60, 1883) ran on the Long Island Railroad, but these were quite a bit smaller. The firebox on the L class was shallow, narrow and long with a sharply sloped backhead.

Specifications by Steve Llanso of Sweat House Media
ClassOld L
Locobase ID5489
RailroadPennsylvania (PRR)
Number in Class1
Road Numbers
Number Built1
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)7
Engine Wheelbase (ft)31.33
Ratio of driving wheelbase to overall engine wheebase 0.22
Overall Wheelbase (engine & tender) (ft)31.33
Axle Loading (Maximum Weight per Axle) (lbs)32,500
Weight on Drivers (lbs)59,750
Engine Weight (lbs)124,100
Tender Loaded Weight (lbs)
Total Engine and Tender Weight (lbs)124,100
Tender Water Capacity (gals)1680
Tender Fuel Capacity (oil/coal) (gals/tons) 1.50
Minimum weight of rail (calculated) (lb/yd)50
Geometry Relating to Tractive Effort
Driver Diameter (in)62
Boiler Pressure (psi)125
High Pressure Cylinders (dia x stroke) (in)17" x 24"
Tractive Effort (lbs)11,886
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.03
Heating Ability
Firebox Area (sq ft)
Grate Area (sq ft)21.05
Evaporative Heating Surface (sq ft)
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2631
Same as above plus superheater percentage2631
Same as above but substitute firebox area for grate area
Power L1
Power MT


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