Dunnellon Phosphate Company 4-6-0 "Ten-wheeler" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 7 (Locobase 13205)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 31, p. 78. See also Richard E Prince, Seaboard Air Line Railway: steam boats, locomotives, and history (Indiana University Press, 1969), p. 121, and "Phosphate Mining," The American Fertilizer, Volume 36 (6 April 1912), pp. 46-50. Baldwin works numbers were 32173 and 32220 in November 1907 and 37692 in April 1912.

Surface-mining hard-rock phosphate deposits in Florida led to the incorporation of the Dunnellon Phosphate Company. They bought up the Standard & Hernando, which had built 13 miles from Hernando to Rockwell Junction, and extended the line to Port Inglis; all track weight 56 lb/yard (28 kg/metre). According to Prince, this gave them a port that they developed as a phosphate exporter.

As the decade wore on, mileage increased to 28 miles and traffic included some fruit movement and some saw-mill output. The Seaboard created the Florida Central & Gulf in 1916 to run the S & H trackage. It was abandoned in 1931.

The first two Ten-wheelers in this class came to Dunnellon at a time when such Ten-wheelers were typical light freight engines in the South. Both stayed with this line until it was closed in 1931. 9 arrived 5 years later and apparently was one engine too many so it was sold to the Tavares & Gulf as their 106 in 1919. After a short stint with the T & G, 106 was claimed by locomotive rebuilder/reseller Southern Iron & Equipment. In November 1921, Grand Prairie Gravel bought the 106.

Specifications by Steve Llanso of Sweat House Media
Locobase ID13205
RailroadDunnellon Phosphate Company
Number in Class3
Road Numbers8, 7, 9
Number Built3
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase11.33'
Engine Wheelbase22.17'
Ratio of driving wheelbase to overall engine wheebase 0.51
Overall Wheelbase (engine & tender)48.87'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers92500 lbs
Engine Weight116500 lbs
Tender Light Weight90000 lbs
Total Engine and Tender Weight206500 lbs
Tender Water Capacity4500 gals
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)51 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"
Boiler Pressure180 psi
Cylinders (dia x stroke)18" x 26"
Tractive Effort23016 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.02
Heating Ability
Firebox Area152 sq. ft
Grate Area22.40 sq. ft
Evaporative Heating Surface1920 sq. ft
Superheating Surface
Combined Heating Surface1920 sq. ft
Evaporative Heating Surface/Cylinder Volume250.73
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4032
Same as above plus superheater percentage4032
Same as above but substitute firebox area for grate area27360
Power L15880
Power MT420.43

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