Arcata & Mad River 2-4-0 "Porter" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class Hoopa (Locobase 12463)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 23, p. 182. (Thanks to Chris Hohl for his 26 May 2017 email noting a mistake in wheel arrangement.) Works number was 18564 in January 1901.

The A&MR RR served the logging industry by delivering the product to Humboldt Bay. Built as plank road in the 1850s, the line later adopted this odd gauge (1,163 mm), roughly halfway between the 3' (914 mm) and standard gauge widths usually used in North America.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID12,463
RailroadArcata & Mad River
Number in Class1
Road Numbers5
Gauge3' 9.25
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 6.25 / 1.90
Engine Wheelbase (ft / m)12.33 / 3.76
Ratio of driving wheelbase to overall engine wheebase 0.51
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)26,000 / 11,793
Engine Weight (lbs / kg)32,000 / 14,515
Tender Loaded Weight (lbs / kg)20,000 / 9072
Total Engine and Tender Weight (lbs / kg)52,000 / 23,587
Tender Water Capacity (gals / ML)800 / 3.03
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)22 / 11
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)37 / 940
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)10" x 16" / 254x406
Tractive Effort (lbs / kg)5881 / 2667.58
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.42
Heating Ability
Firebox Area (sq ft / m2)43 / 4
Grate Area (sq ft / m2) 8.19 / 0.76
Evaporative Heating Surface (sq ft / m2)308 / 28.62
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)308 / 28.62
Evaporative Heating Surface/Cylinder Volume211.77
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1310
Same as above plus superheater percentage1310
Same as above but substitute firebox area for grate area6880
Power L13548
Power MT601.69

All material Copyright ©
Wes Barris