SNCB 4-4-2 Locomotives in Belgium

Class Details by Steve Llanso of Sweat House Media

Class Class 12 (Locobase 2600)

Among the very last 4-4-2s, the arrangement chosen here reflected similar requirements to those that resulted in the Milwaukee Road's Class As -- fast running, relatively light train, need to support a wide firebox. One big difference was the Belgian decision to put the cylinders inside to reduce oscillations. Their streamline casings had big cutouts for the coupled drivers and the piston valves, but otherwise hid the locomotive under an apple-green bathtub with tightly held elephant ears.

The Brussels-Ostend run for which they had been built was halted by the onset of World War II. The service picked up again after World War II, with the last day coming on 29 July 1962.

Data provided for Bryan Attewell ([] Steam Locomotive Simulator (December 2000) shows a tube length of 15.3 ft, which is more in line with an Atlantic's other dimensions.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassClass 12
Locobase ID2600
Number in Class6
Road Numbers12001-12006
Number Built6
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.54 / 2.30
Engine Wheelbase (ft / m)32.44 / 9.89
Ratio of driving wheelbase to overall engine wheelbase 0.23
Overall Wheelbase (engine & tender) (ft / m)57.47 / 17.52
Axle Loading (Maximum Weight per Axle) (lbs / kg)52,000 / 23,587
Weight on Drivers (lbs / kg)101,000 / 45,813
Engine Weight (lbs / kg)
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)6300 / 23.86
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 8.80 / 8
Minimum weight of rail (calculated) (lb/yd / kg/m)84 / 42
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)82.70 / 2101
Boiler Pressure (psi / kPa)261.10 / 18
High Pressure Cylinders (dia x stroke) (in / mm)18.9" x 28.35" / 480x720
Tractive Effort (lbs / kg)27,177 / 12327.29
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.72
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)19 / 5.79
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)39.80 / 3.70
Evaporative Heating Surface (sq ft / m2)1729 / 160.69
Superheating Surface (sq ft / m2)678 / 63.01
Combined Heating Surface (sq ft / m2)2407 / 223.70
Evaporative Heating Surface/Cylinder Volume187.82
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,392
Same as above plus superheater percentage13,301
Same as above but substitute firebox area for grate area
Power L1
Power MT

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