Class A-1 (Locobase 6519)

Data from B & OSW diagram book dated July 1900 supplied by Allen Stanley from his extensive collection May 2005. Works numbers were 18602-18604, 18616, 18626 in January 1901. See Locobase 2017 for the origins of the B & OSW. See Locobase 2017 for the origins of the B & OSW.

According to Drury (1993), this class was delivered as Vauclain compounds with 15" HP and 25" LP cylinders. As completed, they were considerably lighter than they would be later, putting 83,400 lb on the drivers and 149,600 lb on all locomotive axles.

At the time, the Garrett County (Maryland) Republican News -- 01/31/1901-(Vol.24, No.47) -- reported that "Railroaders say these engines "run like a scared dog." They will haul the fast trains." . http://www.therepublicannews.com/archive/old%20archive/013101no9.html, accessed 26 September 2005.

They were soon converted (in 1904) to the simple-expansion variety shown in the specs. In this configuration, they operated into the 1920s with the last retiring in 1929.

Class A-2 (Locobase 6520)

Data from B & OSW diagram book dated July 1900 supplied by Allen Stanley from his extensive collection May 2005. See Locobase 2017 for the origins of the B & OSW.

Drury (1993) and Alvin F Staufer & Lawrence W Sagle, B & O Power (1964). note that these were some of the very few Schenectady engines on the B&O -- these duplicated the Pennsylvania's E-3a. 1474 received superheat and Walschaerts valve gear in 1926; BP increased to 210 psi and tractive effort reached 28,100 lb. See Sagle, 1964, for details

The first retirements began in 1933 and were completed in 1947.

Class A-3 (Locobase 1246)

Works numbers were 34278-34279, 34323-34327 in February 1910; 34355-34364, 34447-34448 in March; 34485-34491 in April.

The last Atlantics, these were built with Walschaert gear and 14"-diameter piston valves. In 1927, the B&O refitted the class with superheaters and 74" drivers; see Locobase 8889.

Class A-3 - superheated (Locobase 8889)

Data from B & O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Locobase 1246 describes the saturated-steam originals. In 1927, the B&O refitted the class with superheaters and 74" drivers, raising tractive effort to 29,360 lb. Weight reached 212,260 lb. All had retired by 1944. Sagle, 1964, comments: "The Atlantics were good, fast engines, and gave adequate service [on several divisions]. For a time they hauled the 'varnish', but as train loads increased ...they were forced off the main lines by Pacific-type locomotives ....They did not have a very glamorous existence on the B&O."

Class A-9/A-10 (Locobase 2082)

Atlantics with different driver sizes. The first had 73" drivers and came from Schenectady in 1904, the later two had 69" drivers and arrived from Brooks in 1906. Photographs of the engines in B&O service, show that the sand dome was much farther forward in the 1486 than in the earlier two.

In 1932, the Buffalo & Susquehanna came under B&O control. The three engines were renumbered 1484-1486. 1486 was retired in 1936. The other two endured until 1948 because flooding washed some of the line during the 1940s and isolated the rest of the B&S.

Sagle 1964; data from Baltimore & Ohio Steam and Electric Locomotive Diagrams by Alvin Staufer (self-published in 1964), supplied by Allen Stanley in May 2005 from his extensive collection.

Class W-2 - simple (Locobase 2058)

The Buffalo, Rochester, & Pittsburgh Railroad was a sizable regional railroad whose main line ran south from Rochester, NY through Bradford, Ridgway, Du Bois, Punxsutawney, and Butler, PA to the junction at Gallery where it shared track to Pittsburgh. The BR&P fell under B&O control on 1 January 1932. (Sagle 1964). Drury (1993) says that the BR&P "was a prosperous railroad, and the prosperity was reflected in their locomotives."

These Atlantics were built in twos -- 2 by Brooks, 2 by Baldwin -- and had inside piston valves. As shown in Railroad Gazette (13 December 1901), these were big, powerful engines with a relatively high boiler pressure, 11" piston valves, and generous heating surface.

The two Brooks engines (162-163) were renumbered in 1932 to 1487-1488 and retired in 1937. The Baldwin engines were not carried over. #161 went to the Fernwood, Columbia & Gulf in Mississippi as their #15, but it was out of place and not often used, one suspects. It was retired by 1936.

Class W-2 - superheated (Locobase 9637)

Data from "Comparative Service Tests of Locomotives," Railway Age Gazette (Vol. 53, No 11, 13 September 1912), pp.469-472.

The RAG article describes the BR & P's test of the merits of installing a superheater in an otherwise unaltered Atlantic that used the same boiler as the superheated Consolidation shown in Locobase 2061. Among other results was a 22% decrease in water use per ton/mile and a 16% drop in coal use. Considering the relatively small superheater, these tests suggested that the railroad could derive a substantial benefit from adopting the new technology.

The two Brooks engines (162-163) were renumbered in 1932 to 1487-1488 and retired in 1937. The Baldwin engines were not carried over. #161 went to the Fernwood, Columbia & Gulf in Mississippi as their #15, but it was out of place and not often used, one suspects. It was retired by 1936.

Class W-3 (Locobase 2060)

Similar to W-2s, but mounting cylinders 1" smaller in diameter.

At some point, the class was rebuilt with a superheater; the specs reflect that upgrade and come from the BR & P's 1930 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive collection. The superheater area is an estimate and based on the figure for the nearly identical Pittsburgh & Lake Erie engines shown in Locobase 6764.

The last 3 were renumbered in 1932 to 1489-1491; they were retired by 1936. Sagle 1964. Drury (1993) says the engines were built by Brooks.

Class W-8/W-8a (Locobase 2059)

These Atlantics had slide valves vs the piston valves of earlier engines; the 174 (W-8a) had Walschaerts valve gear and weighed 195,000 lb. The first 4 became B&O Class A-8, numbered 1492-1495. The last engine became A-8a, 1496. Sagle 1964; data from 1930 BR & P Locomotive Diagram book supplied by Allen Stanley in May 2005 from his extensive collection.

Drury (1993) comments that an oddity of the BR&P Atlantics "was the driver spacing ...as though the builder intended to use 80" drivers, then changed his mind after the locomotive was under construction."