Maryland & Pennsylvania 4-6-0 "Ten-wheeler" Locomotives of 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 Raildata collection. Works numbers were 29760 in December 1906 and 34945 in July 1910.

The Ma and Pa ordered these two Ten-wheelers almost 4 years apart. Specifications described a profile that included 2 1/2% grades and 25-degree curves.

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

Specifications by Steve Llanso of Sweat House Media
Locobase ID7052
RailroadMaryland & Pennsylvania (Ma & Pa)
Number in Class2
Road Numbers27-28
Number Built2
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase12'
Engine Wheelbase23.04'
Ratio of driving wheelbase to overall engine wheebase 0.52
Overall Wheelbase (engine & tender)50.42'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers102960 lbs
Engine Weight128860 lbs
Tender Light Weight79773 lbs
Total Engine and Tender Weight208633 lbs
Tender Water Capacity4000 gals
Tender Fuel Capacity (oil/coal)6 tons
Minimum weight of rail (calculated)57 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"
Boiler Pressure180 psi
Cylinders (dia x stroke)19" x 24"
Tractive Effort23671 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.35
Heating Ability
Firebox Area152 sq. ft
Grate Area25 sq. ft
Evaporative Heating Surface1920 sq. ft
Superheating Surface
Combined Heating Surface1920 sq. ft
Evaporative Heating Surface/Cylinder Volume243.78
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 area27360
Power L15717
Power MT367.24

If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.