Class S-1 (Locobase 58)

Data from tables in 1930 Locomotive Cyclopedia and from Erie 7-1949-1 Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Fireboxes had thermic syphons, boilers had feedwater heaters, valve motion had limited cutoff. The Erie S class had the greatest amount of heating surface of any Berkshires. They were also relatively high-drivered at 70 inches. By the end of steam, they had absolutely enormous tenders that weighed more than most locomotives.

Alfred Bruce (The Steam Locomotive in America, 1950, pp 306-307) loved his Alco engines and these Berks proved no exception. Tossing a bone to Lima's ground-breaking 2-8-4s for the Boston & Albany, Bruce salutes the Eries by claiming it "showed almost unprecedented operational savings in service and firmly the 284 [sic - Bruce never hyphenated a wheel arrangement] with conventional frame construction, long cutoffs and 69-70-in drivers with good counterbalancing. in fast freight service on many roads. This Erie was as outstanding an example of good engineering as was its predecessor the first 284 of the Boston & Albany."

Class S-2 (Locobase 59)

Data from tables in 1930 Locomotive Cyclopedia and from Erie 7-1949-1 Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Fireboxes had 107 sq ft of thermic syphons and 22 sq ft in 2 arch tubes, boilers had Worthington BL feedwater heaters, valve motion had limited cutoff. Ordered from Lima in the same year as the S-1s came from Alco. S-2s had a 2-ft longer engine wheelbase, a slightly greater tractive effort, and larger heating dimensions.

Unlike the Brooks S-1 (Locobase 58) and Baldwin S-3 (Locobase 60), the S-2s were run at 250 psi, but the Erie calculated their tractive effort at 60% cutoff and a 77.5% of MEP and credited the engines with 72,000 lb starting TE.

Starting out with a tender that held 16,500 gallons of water and 24 tons of coal, the S-2 eventually pulled the same big vehicle used by the other Erie Berks - it's shown in the specs.

Class S-3 (Locobase 60)

Data from tables in 1930 Locomotive Cyclopedia and from Erie 7-1949-1 Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Fireboxes had thermic syphons, boilers had feedwater heaters, valve motion had limited cutoff. Completed the set of 105 Berks ordered by the Erie. The S-3 (Baldwin) had the lower boiler pressure of the S-1 but the longer engine wheelbase of the S-2.

Class S-4 (Locobase 9242)

Data from tables in 1930 Locomotive Cyclopedia and from Erie 7-1949-1 Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Fireboxes had 107 sq ft of thermic syphons and 22 sq ft in 2 arch tubes, boilers had Worthington BL feedwater heaters, valve motion had limited cutoff of the 14" piston valves. Completed the set of 105 Berks ordered by the Erie with only a few changes. Like the other Limas (S-2; see Locobase 59), the S-4s were run at 250 psi, but the Erie calculated their tractive effort at 60% cutoff and a 77.5% of MEP and credited the engines with 72,000 lb starting TE.