Mount Gretna 4-4-0 "American" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 15 (Locobase 10141)

Data from "Narrow Gauge Locomotive, C & L Ry USA," The Locomotive Magazine, Vol V (March 1900), p.46. See also DeGolyer, Vol 15, p. 240.

Although the article has a photograph that clearly shows the Cornwall & Lebanon name on the tender and the 15 on tender and cab, Connelly's Baldwin records do not list a Cornwall & Lebanon - at first. Digging into Google, Locobase finds that a portion of the description in the LM article is incorrect - this locomotive was produced not in 1898, but in 1890 (works number 10946). There, however, Connelly's entry credits the engine with 10" x 16" cylinders. Two others - 11-12 (works numbers 10056 and 10100) had 10" x 14" cylinders; they were produced in July 1889 with 11's construction taking only 8 days.

In any case, the LM write-up describes an railroad profile with a maximum grade of 4.5% and 120-ft radius curves on which the doughty 15 could take 25 ton loads. When Locobase puzzled over such a small load, he discovered a Catskill Archive article -- [], last accessed 14 April 2009 -- which noted that the MG - a 4-mile road between Reading and Harrisburg, PA -- was the only 2-ft gauge railroad in the US to use 4-4-0s. Its tracks wound away from a station on the Cornwall & Lebanon, along the shore of Lake Conewago and scaled the 1,120-ft peak of Governor Dick hill.

After it closed as a tourist line, the MG operated a short haul to the Rifle Range for the National Guard until 1916 when an accident involving an overcrowded car injured several guardsmen.

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID10,141
RailroadMount Gretna
Number in Class1
Road Numbers15
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)5 / 1.52
Engine Wheelbase (ft / m)14.50 / 4.42
Ratio of driving wheelbase to overall engine wheebase 0.34
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)21,280 / 9652
Engine Weight (lbs / kg)31,360 / 14,225
Tender Loaded Weight (lbs / kg)24,640 / 11,177
Total Engine and Tender Weight (lbs / kg)56,000 / 25,402
Tender Water Capacity (gals / ML)1440 / 5.45
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)18 / 9
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)33 / 838
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)10" x 14" / 254x356
Tractive Effort (lbs / kg)5409 / 2453.48
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.93
Heating Ability
Firebox Area (sq ft / m2)42 / 3.90
Grate Area (sq ft / m2) 5.95 / 0.55
Evaporative Heating Surface (sq ft / m2)357 / 33.18
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)357 / 33.18
Evaporative Heating Surface/Cylinder Volume280.52
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation893
Same as above plus superheater percentage893
Same as above but substitute firebox area for grate area6300
Power L13676
Power MT761.67

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Wes Barris