These were among the first Atlantics to be delivered to any railroad and the only ones the GRR would operate.
Chris Hohl pointed out a key difference between the Baldwin spec and the railroad's diagram, namely the adhesion weight. Baldwin predicted that the weight on the drivers would be 68,000 lb (30,844 kg). As the Locobase entry now shows, the estimate proved more than seven tons too light. A similar shortfall calculated tube heating surface area as considerably less (1,582 sq ft/146.97 sq m) than the actual figure, possibly because the tubes proved to be 6"(152 mm) longer than originally specified..
Less wide of the mark was the engine weight, originally estimated at 120,000 lb (54,431 kg). The diagram also sparked revisions in wheelbase and tender coal capacity.
They were renumbered 501-502 in 1917.
Both were scrapped in 1935.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Number in Class||2|
|Road Numbers||26, 36/501-502|
|Builder||Burnham, Williams & Co|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||6.25 / 1.90|
|Engine Wheelbase (ft / m)||23.33 / 7.11|
|Ratio of driving wheelbase to overall engine wheebase||0.27|
|Overall Wheelbase (engine & tender) (ft / m)||49.50 / 15.09|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||41,145 / 18,663|
|Weight on Drivers (lbs / kg)||82,290 / 37,326|
|Engine Weight (lbs / kg)||126,940 / 57,579|
|Tender Loaded Weight (lbs / kg)||80,000 / 36,287|
|Total Engine and Tender Weight (lbs / kg)||206,940 / 93,866|
|Tender Water Capacity (gals / ML)||3500 / 13.26|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||8 / 7.30|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||69 / 34.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||70 / 1778|
|Boiler Pressure (psi / kPa)||180 / 12.40|
|High Pressure Cylinders (dia x stroke) (in / mm)||18" x 24" / 457x610|
|Tractive Effort (lbs / kg)||16,996 / 7709.27|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.84|
|Firebox Area (sq ft / m2)||135 / 12.54|
|Grate Area (sq ft / m2)||24.80 / 2.30|
|Evaporative Heating Surface (sq ft / m2)||1807 / 167.87|
|Superheating Surface (sq ft / m2)|
|Combined Heating Surface (sq ft / m2)||1807 / 167.87|
|Evaporative Heating Surface/Cylinder Volume||255.64|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||4464|
|Same as above plus superheater percentage||4464|
|Same as above but substitute firebox area for grate area||24,300|