Maryland & Pennsylvania 4-6-0 "Ten-Wheeler" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 27 (Locobase 7052)

Data from M&PA 1956ca Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volumes 29, p. 209 and 35, pp. 296+. Works numbers were 29760 in December 1906 and 34945 in July 1910.

The Ma and Pa ordered these two Ten-wheelers almost four years apart. Specifications described a profile that included 2 1/2% grades and 25-degree curves. All of the specs for the 28 repeated those for the 27 to the last jot and tittle--even the details about how the tubes were to be swaged down to 2" diameter.

Both were retired in 1955, the 28 first in August and the 27 in December.

Principal Dimensions by Steve Llanso of Middle Run Media
Class27
Locobase ID7052
RailroadMaryland & Pennsylvania (Ma & Pa)
CountryUSA
Whyte4-6-0
Number in Class2
Road Numbers27-28
GaugeStd
Number Built2
BuilderBurnham, Williams & Co
Year1906
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)12 / 3.66
Engine Wheelbase (ft / m)23.04 / 7.02
Ratio of driving wheelbase to overall engine wheelbase 0.52
Overall Wheelbase (engine & tender) (ft / m)50.42 / 15.37
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)102,960 / 46,702
Engine Weight (lbs / kg)128,860 / 58,450
Tender Loaded Weight (lbs / kg)79,773 / 36,184
Total Engine and Tender Weight (lbs / kg)208,633 / 94,634
Tender Water Capacity (gals / ML)4000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)6 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)57 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)180 / 1240
High Pressure Cylinders (dia x stroke) (in / mm)19" x 24" / 483x610
Tractive Effort (lbs / kg)23,671 / 10737.00
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.35
Heating Ability
Tubes (number - dia) (in / mm)228 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.25 / 4.04
Firebox Area (sq ft / m2)152 / 14.13
Grate Area (sq ft / m2)25 / 2.32
Evaporative Heating Surface (sq ft / m2)1920 / 178.44
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1920 / 178.44
Evaporative Heating Surface/Cylinder Volume243.65
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4500
Same as above plus superheater percentage4500
Same as above but substitute firebox area for grate area27,360
Power L15714
Power MT367.05

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