Swiss Western 2-4-0 Locomotives in Switzerland

Class Details by Steve Llanso of Sweat House Media

Class Medoc (Locobase 2543)

Works numbers were 39-48 in 1857.

One of many Stephenson "long-boiler" designs that ran on European railroads from the 1840s until the end of the century. Like so many designs of the period, these engines look front heavy, leading with a tall stack, a steam dome almost as tall with safety-valve appurtances on top, a cylindrical sand bin over the first coupled driver set. This may have been necessary because of the firebox location, which was behind the rear driver set.

When the Swiss Western later became the Jura-Simplon, the engines were renumbered 51, 54-61 and eventually were fitted with air brakes, but were otherwise unmodified until the end of their long service.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID2543
RailroadSwiss Western
Number in Class15
Road Numbers6-15/51, 54-61/1077
Number Built15
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)44.80 / 13.66
Axle Loading (Maximum Weight per Axle) (lbs / kg)20,150 / 9140
Weight on Drivers (lbs / kg)40,000 / 18,144
Engine Weight (lbs / kg)88,500 / 40,143
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)1050 / 3.98
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.60 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)33 / 16.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)66.20 / 1681
Boiler Pressure (psi / kPa)116 / 8
High Pressure Cylinders (dia x stroke) (in / mm)16" x 24" / 406x610
Tractive Effort (lbs / kg)9151 / 4150.83
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.37
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)10.75 / 1
Evaporative Heating Surface (sq ft / m2)1023 / 95.07
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1023 / 95.07
Evaporative Heating Surface/Cylinder Volume183.17
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1247
Same as above plus superheater percentage1247
Same as above but substitute firebox area for grate area
Power L1
Power MT

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