Boston & Maine 4-8-2 "Mountain" Type Locomotives

Class R-1 (Locobase 4410)

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

There were 4 R-1 classes comprising 18 engines -- all were named in contests.

R-1a 4100 Endurance

R-1a 4101 Hannah Dustin

R-1a 4102 Cardigan

R-1a 4103 Oliver Wendell Holmes

R-1a 4104 Bee & Emma

R-1b 4105 Powwow River

R-1b 4106 Little John

R-1b 4107 Intrepid

R-1b 4108 Lily Pons

R-1b 4109 Bumble Bee

R-1c 4110 Calvin Coolidge

R-1c 4111 Trojan

R-1c 4112 Swallow

R-1d 4113 Black Arrow

R-1d 4114 Invincible

R-1d 4115 Casey Jones

R-1d 4116 American Progress

R-1d 4117 Hercules

R-1a (4100-4104) and R-1b (4105-4109) weighed 416,100 lb.

R-1c (4105-09) weighed 414,960 lb.

R-1d (4113-4117) weighed 415,200 lb.

When fitted with 73-in drivers, R-1c had 67,000 lb of tractive effort. Coffin feedwater heaters concealed in the smokebox.

All were built by Baldwin, from 1937-1941. 4100-4112 were sold to the B&O in 1947 as the B&M dieselized.

Specifications
ClassR-1
Locobase ID4410
RailroadBoston & Maine
Whyte4-8-2
Road Numbers4100-4117
GaugeStd
BuilderBaldwin
Year1935
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase19.25'
Engine Wheelbase44.17'
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender)92.67'
Axle Loading (Maximum Weight per Axle)68900 lbs
Weight on Drivers269400 lbs
Engine Weight416100 lbs
Tender Light Weight372700 lbs
Total Engine and Tender Weight788800 lbs
Tender Water Capacity20200 gals
Tender Fuel Capacity (oil/coal)22.5 tons
Minimum weight per yard of rail on which locomotive could run112.25 lb rail
Geometry Relating to Tractive Effort
Driver Diameter73"
Boiler Pressure240 psi
Cylinders (dia x stroke)28" x 31"
Tractive Effort67918 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97
Heating Ability
Firebox Area474 sq. ft
Grate Area79 sq. ft
Evaporative Heating Surface4544
Superheating Surface1924
Combined Heating Surface6468
Evaporative Heating Surface/Cylinder Volume205.68
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation18960
Same as above plus superheater percentage24599.93
Same as above but substitute firebox area for grate area147599.55
Power L132024.50
Power MT1048.28

Credits

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