Mexican 4-6-0 Locomotives in Mexico


Class Details by Steve Llanso of Sweat House Media

Class 51 (Locobase 6739)

Data from MexRy 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

At some point after the MR (Vera Cruz) took over the Pachuca & Tampico, whose origins are outlined in Locobase 6759, it apparently took care to upgrade the somewhat creaky locomotives it found on the roster. The 51 kept its original cylinder volume and driver diameters, but the newer vessel had fewer tubes (170 vs the original 200) and a higher boiler pressure (15 psi or 1.03 bar).

Principal Dimensions by Steve Llanso of Middle Run Media

Class51
Locobase ID6739
RailroadMexican
CountryMexico
Whyte4-6-0
Number in Class1
Road Numbers51
GaugeStd
Number Built
BuilderMR
Year1939
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.37 / 3.16
Engine Wheelbase (ft / m)20.39 / 6.21
Ratio of driving wheelbase to overall engine wheelbase 0.51
Overall Wheelbase (engine & tender) (ft / m)49.62 / 15.12
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)79,071 / 35,866
Engine Weight (lbs / kg)105,138 / 47,690
Tender Loaded Weight (lbs / kg)82,916 / 37,610
Total Engine and Tender Weight (lbs / kg)188,054 / 85,300
Tender Water Capacity (gals / ML)4500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2850 / 10,787
Minimum weight of rail (calculated) (lb/yd / kg/m)44 / 22
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)17" x 24" / 432x610
Tractive Effort (lbs / kg)16,845 / 7640.77
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.69
Heating Ability
Tubes (number - dia) (in / mm)170 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.31 / 3.75
Firebox Area (sq ft / m2)145 / 13.47
Grate Area (sq ft / m2)22 / 2.04
Evaporative Heating Surface (sq ft / m2)1241 / 115.33
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1241 / 115.33
Evaporative Heating Surface/Cylinder Volume196.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3520
Same as above plus superheater percentage3520
Same as above but substitute firebox area for grate area23,200
Power L14653
Power MT389.20

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