Short of power during World War II, the Richmond, Fredericksburg & Potomac turned to Lima Locomotive Works for ten 2-8-4s of the 571 class. They were virtual duplicates of the Nickel Plate's S-1 class being erected at the same time, the principal visible difference being the application of an inboard-journal pilot truck. Arriving in 1943, they weighed 434,000 pounds and mustered 64,135 pounds of tractive effort. They had the typical 69-inch drivers of the Advisory Mechanical Committee design, with cylinder dimensions of 25x34 inches, and sustained 245 p.s.i. of boiler pressure. Their evaporative heating surface totaled 4772 square feet, their superheater surface 1932 square feet, and their grate area 90 square feet. No. 574 was chosen for this Lima builder's photo. These Berkshires had a brief service life, as all were retired by 1952.