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 ID13,801 14,114
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 Wheelbase (ft)13.1711.33
Engine Wheelbase (ft)22.9821.58
Ratio of driving wheelbase to overall engine wheebase 0.57 0.53
Overall Wheelbase (engine & tender) (ft)45.5749.21
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)73,00095,000
Engine Weight (lbs)98,000119,600
Tender Loaded Weight (lbs)70,000100,000
Total Engine and Tender Weight (lbs)168,000219,600
Tender Water Capacity (gals)35005000
Tender Fuel Capacity (oil/coal) (gals/tons)57
Minimum weight of rail (calculated) (lb/yd)4153
Geometry Relating to Tractive Effort
Driver Diameter (in)5656
Boiler Pressure (psi)180180
High Pressure Cylinders (dia x stroke) (in)16" x 24"18" x 24"
Tractive Effort (lbs)16,78621,245
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.35 4.47
Heating Ability
Firebox Area (sq ft)90140
Grate Area (sq ft)15.5021.50
Evaporative Heating Surface (sq ft)12221622
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)12221622
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 area16,20025,200
Power L150295519
Power MT455.63384.23


If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.