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 (cnum.cnam.fr/CGI/fpage.cgi?8XAE277-11.1/54/100/312/0/0 (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 Middle Run Media | |
|---|---|
| Class | 33 |
| Locobase ID | 7377 |
| Railroad | Bayonne-Biarritz |
| Country | France |
| Whyte | 0-6-0T |
| Number in Class | 2 |
| Road Numbers | |
| Gauge | Std |
| Number Built | 2 |
| Builder | Mallet |
| Year | 1877 |
| Valve Gear | Stephenson |
| 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 wheelbase | 1 |
| 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) | |
| 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 / 1000 |
| 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 Volume | 510.46 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1966 |
| Same as above plus superheater percentage | 1966 |
| Same as above but substitute firebox area for grate area | 8893 |
| Power L1 | 3884 |
| Power MT | 456.94 |