Philadelphia, Germantown & Norristown 2-2-0 "Planet" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class Old Ironsides (Locobase 3221)

Heating surface and grate area from Sinclair (1907). See also John H White, Jr, A History of the American Locomotive: Its Development: 1830-1880 (New York: Dover Publications, 1979, p. 8 Works number 1 in December 1832. (Thanks to Chris Hohl for his 11 November 2017 email noting the correct name of the railroad and estimated engine weight.)

This engine, Matthias Baldwin's first to be built from scratch, is said by John H White to have been copy of the Planet type increasingly in use in England (Locobase 651). Baldwin had assembled the Delaware, imported from Robert Stephenson & Co for the New Castle & Frenchtown, and almost immediately turned out this example. Paul T Warner's 1925 history of the Baldwin works (reproduced in Westing, 1966) perhaps has a better view of the relationship when it describes Old Ironsides as "modeled essentially" on the English practice of the day.

Its front carrying axle had wheels that at 45" diameter were almost as tall as the drivers. In most other respects, Baldwin followed British practice. Although possessing some idiosyncracies, like a single exhaust header connecting the two cylinders -- which was soon changed to individual exhaust pipes into the smokebox, the engine performed reasonably well, giving rise to hopes, according to the November 24, 1832 Chronicle, that the engine might draw 30 tons at 40 mph.

It quickly proved too small for growing traffic demands.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassOld Ironsides
Locobase ID3221
RailroadPhiladelphia, Germantown & Norristown
Number in Class1
Road Numbers
Number Built1
BuilderMatthias Baldwin
Valve Gear
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)
Engine Weight (lbs / kg)11,000 / 4536
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 1372
Boiler Pressure (psi / kPa)40 / 2.80
High Pressure Cylinders (dia x stroke) (in / mm)9.5" x 18" / 241x457
Tractive Effort (lbs / kg)1023 / 464.03
Factor of Adhesion (Weight on Drivers/Tractive Effort)
Heating Ability
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2) 6.78 / 0.63
Evaporative Heating Surface (sq ft / m2)209 / 19.42
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)209 / 19.42
Evaporative Heating Surface/Cylinder Volume141.53
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation271
Same as above plus superheater percentage271
Same as above but substitute firebox area for grate area
Power L1
Power MT

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Wes Barris