Mountain Quarries Company / Pacific Portland Cement Company 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 101 (Locobase 14078)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 45, p. 229. Works number was 36824 in August 1911.

Pacific Portland Cement ordered this Mikado and sized it to roll on 75 lb/yard (37.5 kg/metre) rail for the 7 miles between the quarries and the Southern Pacific junction at Auburn, Calif. It trailed a cylindrical Vanderbilt tender.

According to [external link], a triple-span concrete bridge was built in 1912 during construction to handle the 4 trains a day. Quarrying the huge limestone formation took place from 1912 to 1939. In 1942 the tracks were pulled out for scrap metal for WWII, but the "No-Hands Bridge" remains standing. Its nickname reportedly refers to a horseback rider who rode "no hands" as he and his mount (who deserves at least half of the credit) picked their way across the bridge 150 feet above the gorge using only the narrow railbed.

The 101 had long since gone to the Ray & Gila Valley in 1916 and remained on the line until it was sold to Kennecott Copper in December 1943.


Class 102 (Locobase 14255)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 52, p. 116. Works number was 42912 in February 1916 and 59126 in April 1926.

This Mikado was small as 2-8-2s went, but sizable for the industrial line on which it operated. The specs guaranteed it would haul four loaded 50-ton standard steel cars, of either gondola or hopper bottom type, on 75 lb/yard (37.5 kg/metre) rail at 10 mph up a 3 1/2% grade with a 16 degree (359 foot/109.4 metre radius) curve.

In 1926, specifications required that the 103 had offer at least the hauling power of the 102. It weighed a ton more on the drivers and replaced the slide valves of the original design with 12" (305 mm) piston valves, but was otherwise a duplicate.

The 102 later ran on the Ray Consolidated Copper Company rails as their 17 in Hayden, Ariz. McCloud River bought the 17 in 1942 and ran it until 1955. 103 went from PPCC to the California & Oregon Coast in 1941.

Principal Dimensions by Steve Llanso of Sweat House Media
Class101102
Locobase ID14,078 14,255
RailroadMountain Quarries CompanyPacific Portland Cement Company
CountryUSAUSA
Whyte2-8-22-8-2
Number in Class11
Road Numbers101102-103
GaugeStdStd
Number Built11
BuilderBaldwinBaldwin
Year19121916
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2713.08 / 3.99
Engine Wheelbase (ft / m)31.08 / 9.4727 / 8.23
Ratio of driving wheelbase to overall engine wheebase 0.45 0.48
Overall Wheelbase (engine & tender) (ft / m)60.79 / 18.5355.33 / 16.86
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)185,000 / 83,915138,000 / 62,596
Engine Weight (lbs / kg)232,000 / 105,234177,000 / 80,286
Tender Loaded Weight (lbs / kg)133,500 / 60,55590,000 / 40,823
Total Engine and Tender Weight (lbs / kg)365,500 / 165,789267,000 / 121,109
Tender Water Capacity (gals / ML)7000 / 26.524500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)2940 / 11.102500 / 9.50
Minimum weight of rail (calculated) (lb/yd / kg/m)77 / 38.5058 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)51 / 129544 / 1118
Boiler Pressure (psi / kPa)200 / 13.80180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x71120.5" x 28" / 521x711
Tractive Effort (lbs / kg)45,173 / 20490.1540,917 / 18559.66
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.10 3.37
Heating Ability
Firebox Area (sq ft / m2)193 / 17.93160 / 14.86
Grate Area (sq ft / m2)57 / 5.3041.30 / 3.84
Evaporative Heating Surface (sq ft / m2)3903 / 362.603108 / 288.74
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)3903 / 362.603108 / 288.74
Evaporative Heating Surface/Cylinder Volume316.82290.56
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,4007434
Same as above plus superheater percentage11,4007434
Same as above but substitute firebox area for grate area38,60028,800
Power L167184823
Power MT320.23308.20