Here the lone member of class S-1a, No. 6000, reposes briefly in the yards of the Cincinnati Union Terminal in this photo from my brother David's collection. It was taken in September 1954, but the photographer is unknown. This first Niagara had 25x32-inch cylinders and a boiler pressure of 290 p.s.i.; in a subsequent shopping her boiler pressure was reduced to 275 p.s.i. to match that of the S-1b class, with the cylinder diameter increased to 25½ inches to compensate. No. 6000 remained in service until early in 1956. This photo appears in The Steam Locomotive's Energy Story by Walter Simpson, published in 2021 by The Chesapeake & Ohio Historical Society, Inc.