The Berkshire, or 2-8-4, type took its name from the New England mountain chain traversed by the Boston & Albany, for the B&A was the first railroad to order locomotives of this type. In 1925 Lima Locomotive Works demonstrated its pilot model of the "super-power" locomotive, featuring a large firebox requiring a four-wheel trailing truck for support. The railroad, impressed by how Lima's No. 1 vastly outperformed the H-10 2-8-2 — itself an improved steamer over previous Mikados — quickly ordered 25 near-duplicates delivered in 1926, which became its class A-1a. They had 63-inch driving wheels, 28x30-inch cylinders, and sustained 240 pounds per square inch of boiler pressure. They weighed 389,000 pounds and developed 69,400 pounds of tractive effort, with a booster bringing the total to 81,400 pounds.

No. 1410 is shown here at West Springfield, Massachusetts, on September 15, 1946 in an image, photographer unspecified, that came to our NYC Collection from Carl Weber. With the progress of B&A dieselization this locomotive was transferred to the New York Central's other eastern lines in 1948. However, it saw only a brief service life there, being retired and scrapped the following year. Ironically the original Lima demonstrator, No. 1, became the Illinois Central's No. 7050 (renumbered to 8049 in 1941) and outlasted all the B&A Berkshires, being scrapped in 1954.