Atlanta, Birmingham & Atlantic 4-6-2 "Pacific" Type Locomotives

Class 71 (Locobase 7609)

Data from AB&C 11-1930 AB&C 6 1942 Locomotive Diagrams and Passenger Car Data book supplied in May 2005 by Allen Stanley from his extensive collection.

When orginally sold to the Florida East Coast railroad, these Pacifics had saturated boilers as shown in Locobase 5716. Several years before they were sold to the AB & C, the class was superheated (Locobase 3138). Then the class was sold to the AB & C.

Most remained relatively unchanged, but the 79 (works# 53908) was streamlined in December 1940 to head up the Dixie Flagler with the results as shown here. Very little on the locomotive was changed, but a skyline casing was added as well as a bullet-tipped smokebox cover. Also, the tender grew considerably and now weighed 210,500 lb when loaded with 11,000 gallons of water and 18 tons of coal.

Specifications
Class71
Locobase ID7609
RailroadAtlanta, Birmingham & Atlantic (AB&C)
Whyte4-6-2
Road Numbers79
GaugeStd
BuilderAlco
Year1913
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase12.33'
Engine Wheelbase23.08'
Ratio of driving wheelbase to overall engine wheebase 0.53
Overall Wheelbase (engine & tender)73.50'
Axle Loading (Maximum Weight per Axle)44200 lbs
Weight on Drivers132600 lbs
Engine Weight208500 lbs
Tender Light Weight210500 lbs
Total Engine and Tender Weight419000 lbs
Tender Water Capacity11000 gals
Tender Fuel Capacity (oil/coal)18 tons
Minimum weight per yard of rail on which locomotive could run73.67 lb rail
Geometry Relating to Tractive Effort
Driver Diameter69"
Boiler Pressure210 psi
Cylinders (dia x stroke)22" x 26"
Tractive Effort32554 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.07
Heating Ability
Firebox Area160 sq. ft
Grate Area46.90 sq. ft
Evaporative Heating Surface2111
Superheating Surface442
Combined Heating Surface2553
Evaporative Heating Surface/Cylinder Volume184.54
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9849
Same as above plus superheater percentage11554.15
Same as above but substitute firebox area for grate area39417.16
Power L114543.82
Power MT725.42

Credits

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