Unknown 4-6-2 "Pacific" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class unknown (Locobase 3305)

The data is from a table of locomotives to which the Estimating Engineer for Alco, compared his company's #50000 in James Partington, "Avoidable Waste in Locomotive Operation as Affected by Design", No. 1816, December 1921 in Transactions of the American Society of Mechanical Engineers, Volume 43 (New York: The Society, 1922), 987-1011. He chose not to identify any of these rivals. (Thanks to Randal O'Toole for his 28 August 2022 email noting an incorrect citation for Partington's paper.)

Locobase had deduced that this entry was the single K29, but was persuaded by a table in the reproduction of the 1913 Alco Bulletin 1016 on Richard Leonard's [] (accessed 16 June 2006) that, at least as delivered, this was not that locomotive. Still, many of the characteristics are similar and Locobase wonders if this reflects a later reworking of the K29.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID3305
Number in Class1
Road Numbers
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.83 / 4.22
Engine Wheelbase (ft / m)36.50 / 11.13
Ratio of driving wheelbase to overall engine wheelbase 0.38
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)201,800 / 91,535
Engine Weight (lbs / kg)308,900 / 140,115
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)112 / 56
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)80 / 2032
Boiler Pressure (psi / kPa)205 / 14.10
High Pressure Cylinders (dia x stroke) (in / mm)27" x 28" / 686x711
Tractive Effort (lbs / kg)44,460 / 20166.74
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.54
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)22 / 6.71
Firebox Area (sq ft / m2)288.60 / 26.82
Grate Area (sq ft / m2)70 / 6.51
Evaporative Heating Surface (sq ft / m2)4035 / 375
Superheating Surface (sq ft / m2)1154 / 107.25
Combined Heating Surface (sq ft / m2)5189 / 482.25
Evaporative Heating Surface/Cylinder Volume217.40
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation14,350
Same as above plus superheater percentage17,507
Same as above but substitute firebox area for grate area72,179
Power L123,363
Power MT765.71

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