JO&S Articulated Locomotives in Hungary

Class Details by Steve Llanso of Sweat House Media

Class Steierdorf (Locobase 683)

Wilhelm Engerth's coupled-tender drive had limitations on mountainous rail lines such as those of the Jassenova, Oravicza, and Steierdorf railroad of Hungary. He and Pius Fink, therefore, developed a kinematic linkage designed to drive the tender axles while conferring great flexibility. A second connecting rod led from the last axle of the driver set to a crank positioned over the first tender axle. An inclined rod near the crank's hub linked these crank bearings to the third axle to keep them in line. At the end of the crank arm was a shorter rod connecting the upper crank to a crank on the hub of the first tender axle. Viewing the action from the side revealed three cranks, 2 on the same level and 1 above, each rotating around its own axis and kept in harmony by the series of connecting rods.

Although complicated, the system worked well on the 4 engines produced for the railroad. the latter 3 were of a modified design that is described in Locobase 11156.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID683
Number in Class4
Road Numbers
Number Built4
Valve Gear
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)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)93,712 / 42,507
Engine Weight (lbs / kg)93,712 / 42,507
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)93,712 / 42,507
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)31 / 15.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)39.40 / 1000
Boiler Pressure (psi / kPa)104.40 / 7.20
High Pressure Cylinders (dia x stroke) (in / mm)18.1" x 24.9" / 460x630
Tractive Effort (lbs / kg)18,373 / 8333.86
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.10
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)15.50 / 1.44
Evaporative Heating Surface (sq ft / m2)1307 / 121.47
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1307 / 121.47
Evaporative Heating Surface/Cylinder Volume176.26
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1618
Same as above plus superheater percentage1618
Same as above but substitute firebox area for grate area
Power L1
Power MT

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