January 44890; February 45058, 45118; March 45278-45279, 45341
June 48941, 49088; July 49238, 49349; August 49487, 49546; September 49735; October 50133; December 50875, 50940
January 51080; February 51203, 51406; March 51515; April 51648, 51715; May 51769, 51827; June 51905, 51939, 51975, 51993, July 52073, 52095; August 52238
Thirty-one engines built for the Reading from 1917 to 1919. Wootten firebox heating surface included 94 sq ft (8.7 sq m) of arch tubes and syphons. This was one of the biggest examples of details that the Baldwin specification stated should be the same as those on the M-1sb Mikados shown in Locobase 9548.
Even with the enormous grate and combustion chamber, these engines were still short of breath. Their duty included pushing service on some of the Reading's 3% grades and heavy traffic.
The class was broken up in the late 1920s when the first eleven engines were converted to K1-sa and K1-sc Santa Fe-type 2-10-2s; see Locobase 83. The remaining compounds were redesignated N1-sb (1816-1830) if they had Standard stokers and N1-sc (1811-1815) if they used the Street Duplex stoker.
All of the twenty remaining engines were eventually rebuilt as N1-sd simple-expansion articulateds with four 23' x 32" cylinders; tractive effort was recalculated as 111,400 lb (50,530 kg), adhesion weight rose to 465,430 lb (211,116 kg) and engine weight grew to 500,700 lb (227,114 kg). The first four engines to be rebuilt --1811, 1816, 1818, and 1821-- were converted by 1936 with the rest completed by 1945.
All of the N1-sd locomotives lost a trailing truck between 1940 and 1944 and operated as 2-8-8-0s. Adhesion weight rose to 477,846 lb (216,748 kg) and engine weight dropped to 495,180 lb (224,610 kg).
Thanks to Chris Hohl, whose September 2012 email alerted me to the ambiguities in the original entry.
|Specifications by Steve Llanso of Sweat House Media|
|Class||N1-sa/-sb, sc, sd|
|Railroad||Philadelphia & Reading|
|Number in Class||31|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||15|
|Engine Wheelbase (ft)||55.83|
|Ratio of driving wheelbase to overall engine wheebase||0.27|
|Overall Wheelbase (engine & tender) (ft)||82.98|
|Axle Loading (Maximum Weight per Axle) (lbs)|
|Weight on Drivers (lbs)||435,200|
|Engine Weight (lbs)||478,500|
|Tender Loaded Weight (lbs)||170,000|
|Total Engine and Tender Weight (lbs)||648,500|
|Tender Water Capacity (gals)||8500|
|Tender Fuel Capacity (oil/coal) (gals/tons)||15.50|
|Minimum weight of rail (calculated) (lb/yd)||91|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||55.50|
|Boiler Pressure (psi)||210|
|High Pressure Cylinders (dia x stroke) (in)||26" x 32"|
|Low Pressure Cylinders (dia x stroke) (in)||40" x 32"|
|Tractive Effort (lbs)||97,818|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.45|
|Firebox Area (sq ft)||385|
|Grate Area (sq ft)||108|
|Evaporative Heating Surface (sq ft)||5747|
|Superheating Surface (sq ft)||1436|
|Combined Heating Surface (sq ft)||7183|
|Evaporative Heating Surface/Cylinder Volume||292.26|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||22,680|
|Same as above plus superheater percentage||27,216|
|Same as above but substitute firebox area for grate area||97,020|