Minho e Douro 0-6-0 Locomotives in Portugal

Class Details by Steve Llanso of Sweat House Media

Class 21 (Locobase 9702)

Data from [], last accessed 30 November 2008. Also see "Locomotives of the Minho and Douro Railway, Portugal,"The Locomotive Magazine, Vol VIII (13 June 1903), pp. 409-410.

Originally purchased by the M e D as mixed-traffic locomotives, the class was known in Portugal as the Papa Almoto class. Like many Portuguese locomotives, these engines enjoyed long careers, the last of them operating in the Oporto area until retired in the 1960s.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID9702
RailroadMinho e Douro
Number in Class12
Road Numbers21-32
Number Built12
BuilderBeyer, Peacock
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)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)77,162 / 35,000
Engine Weight (lbs / kg)77,162 / 35,000
Tender Loaded Weight (lbs / kg)44,092 / 20,000
Total Engine and Tender Weight (lbs / kg)121,254 / 55,000
Tender Water Capacity (gals / ML)1848 / 7
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.30 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)43 / 21.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)51 / 1295
Boiler Pressure (psi / kPa)111.70 / 7.70
High Pressure Cylinders (dia x stroke) (in / mm)18.39" x 24.02" / 467x610
Tractive Effort (lbs / kg)15,123 / 6859.69
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.10
Heating Ability
Tubes (number - dia) (in / mm)172 - 1.772" / 45
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)16.57 / 1.54
Evaporative Heating Surface (sq ft / m2)1220 / 113.40
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1220 / 113.40
Evaporative Heating Surface/Cylinder Volume165.21
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1851
Same as above plus superheater percentage1851
Same as above but substitute firebox area for grate area
Power L1
Power MT

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