Bayonne-Biarritz 0-6-0 Locomotives in France

Class Details by Steve Llanso of Sweat House Media

Class 33 (Locobase 7377)

Data from Titre Exposition universelle internationale de 1878 a Paris. Rapports du jury internationale..Volume Groupe VI - Classe 64. Rapport sur le materiel des chemins de fer. p. 50 ( (accessed 1 September 2005) table and page 91.

This was the very first compound tank engine built anywhere and it was product of Jules Anatole Mallet's fertile imagination. The high-pressure cylinder lay on the left side, the low-pressure cylinder on the right. Steam went to the HP cylinder, was exhausted into a "receiver" and from there was conducted to the LP cylinder before being released to the atmosphere. Mallet's compounding ratio lies within good practice, but his two-cylinder system tended to jerk the engine at higher speeds.

Mallet soon developed the 4-cylinder, 2-engine articulated compound design that eventually went into service all over the world.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID7377
Number in Class2
Road Numbers
Number Built2
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.86 / 2.70
Engine Wheelbase (ft / m) 8.86 / 2.70
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m) 8.86 / 2.70
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)56,218 / 25,500
Engine Weight (lbs / kg)56,218 / 25,500
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)56,218 / 25,500
Tender Water Capacity (gals / ML)660 / 2.50
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 0.60 / 1
Minimum weight of rail (calculated) (lb/yd / kg/m)31 / 15.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)47.20 / 1200
Boiler Pressure (psi / kPa)145 / 10
High Pressure Cylinders (dia x stroke) (in / mm)11.02" x 21.65" / 280x550 (1)
Low Pressure Cylinders (dia x stroke) (in / mm)16.54" x 21.65" / 420x550 (1)
Tractive Effort (lbs / kg)4755 / 2156.83
Factor of Adhesion (Weight on Drivers/Tractive Effort)11.82
Heating Ability
Tubes (number - dia) (in / mm)130 - 1.772" / 45
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 9.51 / 2.90
Firebox Area (sq ft / m2)61.33 / 5.70
Grate Area (sq ft / m2)13.56 / 1.26
Evaporative Heating Surface (sq ft / m2)610 / 56.70
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)610 / 56.70
Evaporative Heating Surface/Cylinder Volume510.46
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1966
Same as above plus superheater percentage1966
Same as above but substitute firebox area for grate area8893
Power L13884
Power MT456.94

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