Siam Railways 2-6-0 Locomotives in Thailand

Class Details by Steve Llanso of Sweat House Media

Class unknown (Locobase 10187)

Data from "Mogul Locomotive, Siamese Rys", The Locomotive Magazine, Vol VI (May 1901), p. 88.

At the time of this class's delivery, the railways in Siam/Thailand were still set to standard gauge. When seen from the side, the design looked as if it was missing another driving axle behind the valve gear. Instead, as with many Krauss engines, the pony truck and the first driven axle were combined in a truck that greatly reduced the rigid wheelbase. The fuel was wood, as could be inferred from the large, inversely tapered stack.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID10187
RailroadSiam Railways
Number in Class
Road Numbers
Number Built
Valve GearHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.79 / 2.68
Engine Wheelbase (ft / m)18.37 / 5.60
Ratio of driving wheelbase to overall engine wheelbase 0.48
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)62,170 / 28,200
Engine Weight (lbs / kg)79,366 / 36,000
Tender Loaded Weight (lbs / kg)67,682 / 30,700
Total Engine and Tender Weight (lbs / kg)147,048 / 66,700
Tender Water Capacity (gals / ML)2788 / 10.56
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)35 / 17.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)49.60 / 1260
Boiler Pressure (psi / kPa)174 / 12
High Pressure Cylinders (dia x stroke) (in / mm)17.32" x 21.26" / 440x540
Tractive Effort (lbs / kg)19,017 / 8625.98
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.27
Heating Ability
Tubes (number - dia) (in / mm)198 - 1.732" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.14 / 3.70
Firebox Area (sq ft / m2)90.38 / 8.40
Grate Area (sq ft / m2)17.22 / 1.60
Evaporative Heating Surface (sq ft / m2)1180 / 109.67
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1180 / 109.67
Evaporative Heating Surface/Cylinder Volume203.54
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2996
Same as above plus superheater percentage2996
Same as above but substitute firebox area for grate area15,726
Power L14049
Power MT430.75

All material Copyright ©
Wes Barris