S Pearson & Son 0-6-0 Locomotives in Mexico

Class Details by Steve Llanso of Sweat House Media

Class El Meson (Locobase 16307)

Data from"Tender Locomotive for Mexican Oil Fields", Locomotive Magazine, Volume XIX [19] (15 March 1913), p. 57.

These small oilfield locomotive fittingly burned liquid fuel. LM reported that this were the smallest locomotives to use Holden's patent oil to burn refinery waste product. The circular steel firebox was fitted with firebars, but these were covered with broken fire brick onto which the burner sprayed the fuel. The firebox also had a "special" brick arch.

"The locomotives." added LM, "have given a very good account of themselves and satisfaction to Messrs Pearson."

Principal Dimensions by Steve Llanso of Sweat House Media

ClassEl Meson
Locobase ID16307
RailroadS Pearson & Son
Number in Class1
Road Numbers
Number Built1
BuilderWG Bagnall
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 5.75 / 1.75
Engine Wheelbase (ft / m) 5.75 / 1.75
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)14,560 / 6604
Engine Weight (lbs / kg)14,560 / 6604
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)420 / 1.59
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)180 / 681
Minimum weight of rail (calculated) (lb/yd / kg/m)8 / 4
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)19 / 483
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)6.5" x 9" / 165x229
Tractive Effort (lbs / kg)2552 / 1157.57
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.71
Heating Ability
Tubes (number - dia) (in / mm)50 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 5.08 / 1.55
Firebox Area (sq ft / m2)13 / 1.21
Grate Area (sq ft / m2) 4.20 / 0.39
Evaporative Heating Surface (sq ft / m2)128 / 11.90
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)128 / 11.90
Evaporative Heating Surface/Cylinder Volume365.71
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation630
Same as above plus superheater percentage630
Same as above but substitute firebox area for grate area1950
Power L12619
Power MT1189.68

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