Minas y Ferro Carril de Utrillas Articulated Locomotives in Spain

Class Details by Steve Llanso of Sweat House Media

Class 51 (Locobase 10992)

Data from Record of Recent Construction #91 (Baldwin Locomotive Works, 1918), p.14-15. See also DeGolyer, Volume 60, pp. 319. Works numbers were 45531 in April 1917 and 45632 in May.

Baldwin built very small quantities of tank engines in this wheel arrangement. The FC de Utrillas needed locomotives that could handle 3% grades and rails weighing 66 lb/yard (33 kg/metre). "The running gear throughout," said the builder's description of #51, "is built for severe service on rough tracks." It also noted that the short runs meant there was no need for a separate tender. On the other hand, "[t]he fuel and water used are of poor quality, and the boiler has a wide firebox with comparatively large grate area."

The frame had some unusual features dictated by the gauge and the engine's power. Baldwin used plates rather than the by-then much more common bars and the rear unit's frame was wide enough to be outside the wheels, "... in order," said Baldwin," to provide adequate support for the firebox and to insure sufficient stability."

The railway's primary traffic was of lignite from the Central Basin north of Teruel, which it delivered to Zaragoza. Unfortunately, the website of the Asociacion Turolense de Amigos de Ferrocarril ([], last accessed 27 November 2009) comments, Zaragoza did not have a big appetite for coal nor was it easy to export coal from that city. So traffic levels fell and the line eventually closed in 1966.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID10992
RailroadMinas y Ferro Carril de Utrillas
Number in Class2
Road Numbers51-52
Gauge3' 4"
Number Built2
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)8 / 2.44
Engine Wheelbase (ft / m)23.50 / 7.16
Ratio of driving wheelbase to overall engine wheelbase 0.34
Overall Wheelbase (engine & tender) (ft / m)23.50 / 7.16
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)165,200 / 74,934
Engine Weight (lbs / kg)165,200 / 74,934
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)165,200 / 74,934
Tender Water Capacity (gals / ML)2245 / 8.50
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)46 / 23
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)41 / 1041
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)16" x 22" / 406x559
Low Pressure Cylinders (dia x stroke) (in / mm)25" x 22" / 635x559
Tractive Effort (lbs / kg)33,133 / 15028.89
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.99
Heating Ability
Tubes (number - dia) (in / mm)152 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)15.50 / 4.72
Firebox Area (sq ft / m2)109 / 10.13
Grate Area (sq ft / m2)35.30 / 3.28
Evaporative Heating Surface (sq ft / m2)1336 / 124.16
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1336 / 124.16
Evaporative Heating Surface/Cylinder Volume260.96
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation7060
Same as above plus superheater percentage7060
Same as above but substitute firebox area for grate area21,800
Power L12057
Power MT164.71

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