The Baltimore and Ohio's S-1a 2-10-2s (also known as the "Big Sixes") where built in 1923, and where an upgrade to the 1914 built S class locomotives. The S-1a's (#6100 - 6224) sported larger drivers than the previous 2-10-2s, as well as other improvements to the early design. While most 2-10-2s where built for low speed dragging, the S-1a's where able to pull heavy trains at higher speeds, making them perfect engines for the B&O's Sand Patch Grade. Seen both hauling heavy drag freights as well as serving as helper engines, the S-1a's would remain in service to the very end of B&O steam.
Cooperation with Greencoast Studios, model by Dennis. Available for purchase on the Greencoast Studios store.
TRS19 only: http://x-z.eu/GCSBOS119