Uvalde Street Railway 2-4-0 "Porter" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 2 (Locobase 11375)

Data from "Steam Motors for Street Service", Railway and Locomotive Engineering,, Vol 23, No. 2 (February 1910), p. 66. Works number was 4436 in October 1909.

This little tram motor worked the USR's streets as one of the very last "steam dummies" ordered by a US street railway. Its design had a short nose and long cabin with clerestory running along most of the roof.

Specifications by Steve Llanso of Sweat House Media
Locobase ID11,375
RailroadUvalde Street Railway
Number in Class1
Road Numbers2
Number Built1
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)
Engine Wheelbase (ft)
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender) (ft)
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)20,000
Engine Weight (lbs)28,500
Tender Loaded Weight (lbs)
Total Engine and Tender Weight (lbs)
Tender Water Capacity (gals)300
Tender Fuel Capacity (oil/coal) (gals/tons) 0.10
Minimum weight of rail (calculated) (lb/yd)17
Geometry Relating to Tractive Effort
Driver Diameter (in)30
Boiler Pressure (psi)165
High Pressure Cylinders (dia x stroke) (in)8" x 14"
Tractive Effort (lbs)4189
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.77
Heating Ability
Firebox Area (sq ft)32.50
Grate Area (sq ft) 6.75
Evaporative Heating Surface (sq ft)143
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)143
Evaporative Heating Surface/Cylinder Volume175.57
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1114
Same as above plus superheater percentage1114
Same as above but substitute firebox area for grate area5363
Power L13094
Power MT682.11

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