Boston & Maine 4-4-0 "American" Type Locomotives

Class A (Locobase 3316)

Based on data presented on the B&M 494 Restoration web site. John R. Rogers replied to an email inquiry in September 2001, however, and supplied somewhat different heating and grate areas as well as the actual boiler pressure and driver diameters.

The builders' data comes from a table compiled by B. Rumary based on information from Jeremy Lambert and supplied by Allen Stanley in March 2004. Rumary-Lambert assign works #1543-1550, manufactured in July-August 1892..

According to the web site: "Engine 494, an American type 4-4-0 locomotive, steamed out of the builder's yard at the Manchester Locomotive Works in Manchester, New Hampshire in July 1892. The 494 was originally built for the Eastern Railroad but was later acquired by the Boston & Maine Railroad. In 1911 No. 494 was renumbered as the 905. This historic engine had served the Eastern Railroad and the B&M, hauling passenger cars and light freight. Toward the end, the 494 was used to haul coal from Fabyan Station, at steep grade, to Marshfield Station at the 2700 foot level of Mount Washington, New Hampshire. This coal was used by the Mount Washington Cog Railway for its climb to the 6,288 foot summit. Engine No. 494 was finally retired in 1938." She appeared at the 1939 World's Fair and was later displayed at the town of Hartfort, Vermont.

Class A-41 (Locobase 2380)

Data from 1927 and 1947 Boston & Maine Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive collection.

Built between 1900-1911. Many were used on suburban service out of Boston's North Station.

Specifications
ClassAA-41
Locobase ID33162380
RailroadBoston & MaineBoston & Maine
Whyte4-4-04-4-0
Road Numbers491-498 / 902-909950-1029
GaugeStdStd
BuilderManchesterManchester
Year18921909
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase9'9'
Engine Wheelbase23.59'23.58'
Ratio of driving wheelbase to overall engine wheebase 0.38 0.38
Overall Wheelbase (engine & tender)46.17'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers79000 lbs74000 lbs
Engine Weight104000 lbs115000 lbs
Tender Light Weight90000 lbs
Total Engine and Tender Weight0205000 lbs
Tender Water Capacity3100 gals4000 gals
Tender Fuel Capacity (oil/coal)6 tons7 tons
Minimum weight per yard of rail on which locomotive could run66 lb rail62 lb rail
Geometry Relating to Tractive Effort
Driver Diameter66"69"
Boiler Pressure150 psi190 psi
Cylinders (dia x stroke)18" x 24"18" x 24"
Tractive Effort15022 lbs18200 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.26 4.07
Heating Ability
Firebox Area
Grate Area18.50 sq. ft26 sq. ft
Evaporative Heating Surface16301751
Superheating Surface
Combined Heating Surface16301751
Evaporative Heating Surface/Cylinder Volume230.60247.72
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation27754940
Same as above plus superheater percentage27754940
Same as above but substitute firebox area for grate area00
Power L100
Power MT00

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.