Philadelphia & Reading 2-8-8-2 "Chesapeake" Locomotives in the USA

Class N1-sa/-sb, sc, sd (Locobase 326)

Data from RDG 11 - 1926 Locomotive Diagram book and various editions of the Reading Equipment Lists supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 58, pp. 377+ and 387+. See also "Philadelphia & Reading Mallet Locomotives", Railway Mechanical Engineer, Volume 91, No 6 (June 1917), pp. 333- 334. (Thanks to Chris Hohl, whose September 2012 email alerted me to the ambiguities in the original entry, and for his 30 January 2016 email noting tender differences, sb and sc number series, and a typo in a reference to the sc. Also, thanks to Nate Kelly for his 2 March 2017 email highlighting the differences in the N1-sd, which led to a revision of the version identification in this original Locobase 326 entry.) Works numbers were:

1917

January 44890; February 45058, 45118; March 45278-45279, 45341

1918

June 48941, 49088; July 49238, 49349; August 49487, 49546; September 49735; October 50133; December 50875, 50940

1919

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) in the combustion chamber. Standard stokers handled a 50-50 mixture of anthracite buckwheat and bituminous coal "very satisfactorily", according to RME. 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. So too were the 14" (356-mm) piston valves.

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 these were fitted with Nicholson thermic syphons

All but one of the twenty remaining engines were eventually rebuilt as N1-sd simple-expansion articulateds; see Locobase 16269.

Class N1-sd (Locobase 16269)

Data from RDG 11 - 1926 Locomotive Diagram book and various editions of the Reading Equipment Lists supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Nate Kelly for his 2 March 2017 email highlighting the differences in the N1-sd, which led to a revision of the version identification in the original Locobase 326 entry. Also, thanks to Chris Hohl for his 24 December 2021 email )

Thirty-one Mallet articulateds were delivered to the Reading from 1917 to 1919; they're shown in Locobase 326.

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. They had Wootten fireboxes and Hulson grates. Their firebox heating surface areas included the original 92 sq ft (8.55 sq m) in the combustion chamber and an added 98 sq ft (9.10 sq m) in two thermic syphons. They were fitted with Ragonnet 9" Type A power reverse gear. 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).