McCloud River Other Articulated Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 5 (Locobase 3575)

Data from Wiener (1930); see also "Duplex Compound Locomotive for the McCloud River Railroad," Railroad Gazette, Volume 32, No 22 (1 June 1900), p. 351. See also DeGolyer, Volume 22, p. 277. (Thanks to Chris Hohl for his 4 July 2018 email noting the fuel capacity.) Works numbers for the two engines were 17684-17685 in April 1900.

Unusual wood-fired compound duplex (twin) locomotive design for the 18-mile Central Californian railroad. Two engines joined back to back with their reversing gear ganged by a parallel link. Designed for very steep railroads, the design was rated at 125 tons up 7%.

A photograph in Westing (1966) shows the oddball result. For one thing, the two locomotives were not quite symmetrical. One had a saddle tank, the other a pannier tank with wood racks outside. Fuel capacity amounted to 380 cu ft (10.76 cu m) or just under three cords.

On the other hand, both engines had the diamond-shaped spark-arresting stack and ornately curved sand and steam domes, the latter with the safety valve on top. Cylinders rode with the piston valve below and driven by inside valve gear. And each engine had its own bell.

According to a website that documents the McCloud -- [], accessed 8 December 2005 -- the two engines were soon separated because the tandem "...derailed constantly on the light trackage." As number #5, one of the two was sold in 1919 to Weed Lumber Company, then was scrapped after sale and use by Lystul-Watson Logging Company. #6 first went to Atkinson Construction Co. #6, then to A.D. Schader as their #6, and finally to Permanente Metals Co as #2515. Much longer lived than its twin, this engine was scrapped in 1949.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID3575
RailroadMcCloud River
Number in Class2
Road Numbers5-6
Number Built2
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.75 / 2.97
Engine Wheelbase (ft / m)38.33 / 11.68
Ratio of driving wheelbase to overall engine wheebase 0.25
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)161,504 / 73,257
Engine Weight (lbs / kg)161,504 / 73,257
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)161,504
Tender Water Capacity (gals / ML)2400 / 9.09
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)45 / 22.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)40 / 1016
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)11.5" x 20" / 292x508
Low Pressure Cylinders (dia x stroke) (in / mm)19" x 20" / 483x508
Tractive Effort (lbs / kg)16,455 / 7463.87
Factor of Adhesion (Weight on Drivers/Tractive Effort) 9.81
Heating Ability
Firebox Area (sq ft / m2)148 / 13.75
Grate Area (sq ft / m2)26 / 2.42
Evaporative Heating Surface (sq ft / m2)1952 / 181.41
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1952 / 181.41
Evaporative Heating Surface/Cylinder Volume811.85
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5200
Same as above plus superheater percentage5200
Same as above but substitute firebox area for grate area29,600
Power L15469
Power MT447.93

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Wes Barris