Paris & Mount Pleasant 4-6-0 "Ten-wheeler" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class 102 (Locobase 13801)

Data from Baldwin Locomotive Works datacard as digitized by the DeGolyer Library of Southern Methodist University, Volume 39, p.20. See also Chris Cravens, "PARIS AND MOUNT PLEASANT RAILROAD," Handbook of Texas Online (http://www.tshaonline.org/handbook/online/articles/eqp06), accessed January 30, 2012. Published by the Texas State Historical Association. Works number was 36628 in May 1911.

Even as late as 1909, railroads were being chartered to fill in gaps in a dense railroad network. According to the Mount Pleasant history website (http://www.mpcity.net/history.htm, last accessed 30 January 2012), "...the difficulty of getting around during the wetter times of the year prompted the formation of the Paris and Mount Pleasant Railroad." The plan was to build from Paris, Texas (a few miles south of Hugo, Oklahoma) southeast to the county seat of Titus County, Mount Pleasant, a distance of 55 miles. Viewed in the context of the usual outcomes of many such shortline ambitions, it's remarkable that the plan was executed to the last milepost. The 24-mile section between Paris and Bogota was completed in less than a year and the additional 27 miles to Mount Pleasant was opened 19 months later in May 1912.

After its completion and despite an extended stay in receivership from 1920-1931, the Pa & Ma served the local communities for 40 years.

The 102 served for almost 3/4 of the time before being retired in 1939-1940.

For a wonder, that's just what happened. The 24-mile section between Paris and Bogota was completed in less than a year and the additional 27 miles to Mount Pleasant was opened 19 months later in May 1912.


Class 103 (Locobase 14114)

Data from Baldwin Locomotive Works datacard as digitized by the DeGolyer Library of Southern Methodist University, Volume 43, p. 193 and 47, p.268. See also Locobase 13801 for a description of the P&MP. Works numbers were 38624 in May 1912 and 40113 in July 1913.

A year after the P&MP bought its first Baldwin Ten-wheeler, it returned to Eddystone for a bigger engine. The 103 was larger than the 102 in every dimension save wheelbase. Sister 104 followed 15 months later.

Both engines operated on the railroad for almost 30 years before being retired in 1939-1940.

Specifications by Steve Llanso of Sweat House Media
Class102103
Locobase ID13801 14114
RailroadParis & Mount PleasantParis & Mount Pleasant
CountryUSAUSA
Whyte4-6-04-6-0
Number in Class12
Road Numbers102103-104
GaugeStdStd
Number Built12
BuilderBaldwinBaldwin
Year19111912
Valve GearStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase13.17'11.33'
Engine Wheelbase22.98'21.58'
Ratio of driving wheelbase to overall engine wheebase 0.57 0.53
Overall Wheelbase (engine & tender)45.57'49.21'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers73000 lbs95000 lbs
Engine Weight98000 lbs119600 lbs
Tender Light Weight70000 lbs100000 lbs
Total Engine and Tender Weight168000 lbs219600 lbs
Tender Water Capacity3500 gals5000 gals
Tender Fuel Capacity (oil/coal)5 tons7 tons
Minimum weight of rail (calculated)41 lb/yard53 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"56"
Boiler Pressure180 psi180 psi
Cylinders (dia x stroke)16" x 24"18" x 24"
Tractive Effort16786 lbs21245 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.35 4.47
Heating Ability
Firebox Area90 sq. ft140 sq. ft
Grate Area15.50 sq. ft21.50 sq. ft
Evaporative Heating Surface1222 sq. ft1622 sq. ft
Superheating Surface
Combined Heating Surface1222 sq. ft1622 sq. ft
Evaporative Heating Surface/Cylinder Volume218.80229.47
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation27903870
Same as above plus superheater percentage27903870
Same as above but substitute firebox area for grate area1620025200
Power L150295519
Power MT455.63384.23


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