Thomas Iron Company 2-4-0 "Porter" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class Pawnee (Locobase 11844)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 13, p.5.

Works number was 7864 in March 1886. See also [] for a history of the three small towns in this area.

Thomas Iron was located in Hokendauqua, Penna in the Lehigh Valley. Established in 1853, the firm produced iron in Hokendauqua until 1929. Its mile-and-a-half railroad connected with the Ironton Railroad at West Coplay. This little four-coupled with leading truck differed from most of the earlier versions of that wheel arrangement in having a Bissel truck. It was one of the TI RR's later acquisitions.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID11844
RailroadThomas Iron Company
Number in Class1
Road Numbers17
Number Built1
BuilderBurnham, Parry, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 4.67 / 1.42
Engine Wheelbase (ft / m)11.25 / 3.43
Ratio of driving wheelbase to overall engine wheelbase 0.42
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)
Engine Weight (lbs / kg)
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)800 / 3.03
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)130 / 9
High Pressure Cylinders (dia x stroke) (in / mm)11" x 16" / 279x406
Tractive Effort (lbs / kg)3820 / 1732.72
Factor of Adhesion (Weight on Drivers/Tractive Effort)
Heating Ability
Tubes (number - dia) (in / mm)111 - 1.5" / 38
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 6.58 / 2.01
Firebox Area (sq ft / m2)35.84 / 3.33
Grate Area (sq ft / m2)10.80 / 1
Evaporative Heating Surface (sq ft / m2)319 / 29.65
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)319 / 29.65
Evaporative Heating Surface/Cylinder Volume181.25
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1404
Same as above plus superheater percentage1404
Same as above but substitute firebox area for grate area4659
Power L13435
Power MT

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