Tunas a Sancti Spiritus 2-6-0 Locomotives in Cuba

Class Details by Steve Llanso of Sweat House Media

Class 5 (Locobase 14370)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 54, p. 69 and Vol 72, pp. 36. Works numbers were 41921 in February 1915 and 57800 in June 1924.

One way to know that this was a true common carrier was to note the rail weight of 56 lb/yard (28 kg/metre). Its layout included generous curves in which the minimum radius was 565 feet (172 metres) or 10 degrees and maximum grades amounted to only 7/8 of 1%. Over this line the 5 was expected to pull 240 tons (218 metric tons) up the maximum grade and around the maximum curve.

But there was one cautionary note for the builder of these wood-burning Moguls: "The bridges on the railway are old and are in need of repair. Give particular attention to limit of weights." Such a warning inspired careful design efforts that went too far, at least in the case of the throttle valve, which was too small and removed to be placed on another locomotive.

The 6, which was produced at Eddystone nine years later put another short ton (907 kg) on the drivers and weighed 63,000 lb (28,576 kg) overall. Its larger tender weighed 20,000 lb (9,072 kg) empty and 43,000 lb (19,504 kg) when carrying two cords of wood and 2,000 US gallons (7,570 litres) of water.

Las Tunas is located 667 km (414 miles) southeast of Havana and 219 km (136 miles) northwest of Santiago de Cuba near the island's eastern tip. The railway that connects the port at Tunas de Zaza to Sancti Spirtus, which lies 24.5 miles (39.4 km) inland, opened in 1863.

The 6's tender was lettered for the FC Espirituano.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID14370
RailroadTunas a Sancti Spiritus
Number in Class2
Road Numbers5-6
Number Built2
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)12 / 3.66
Engine Wheelbase (ft / m)18.83 / 5.74
Ratio of driving wheelbase to overall engine wheelbase 0.64
Overall Wheelbase (engine & tender) (ft / m)38.56 / 11.75
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)50,000 / 22,680
Engine Weight (lbs / kg)60,000 / 27,216
Tender Loaded Weight (lbs / kg)37,000 / 16,783
Total Engine and Tender Weight (lbs / kg)97,000 / 43,999
Tender Water Capacity (gals / ML)1600 / 6.06
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)28 / 14
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)13" x 20" / 330x508
Tractive Effort (lbs / kg)10,945 / 4964.57
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.57
Heating Ability
Tubes (number - dia) (in / mm)112 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 9.23 / 2.81
Firebox Area (sq ft / m2)63 / 5.85
Grate Area (sq ft / m2)11.70 / 1.09
Evaporative Heating Surface (sq ft / m2)599 / 55.65
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)599 / 55.65
Evaporative Heating Surface/Cylinder Volume194.95
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1872
Same as above plus superheater percentage1872
Same as above but substitute firebox area for grate area10,080
Power L13332
Power MT440.75

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