The 2JJ2m9yf Class is a class of 2-10-10-2 Articulated locomotives designed by Howard Knott at the Eastern & Atlantic's Charlotte Works.
The Eastern & Atlantic's Charlotte Works were opened in 1922, as a part of the E&A's new plan for a large fleet of articulated locomotives. Howard Knott moved there as the resident designer in that same year, and began work on the largest locomotive then on the Eastern & Atlantic, a 2-10-10-2. This class was designated 2JJ2m9yf, and carried the first feedwater heater on an articulated locomotive on the E&A.
This large class was so big, many turntables on the E&A simply could not fit the locomotive. Until the turntables were lengthened, the class had to be turned round on the turntable without their tenders.
The class was well-suited to the drag freights it was assigned, performing well at speeds around 15 or 20 miles per hour. The class was never in high demand, so only 6 locomotives were built between 1922 and 1924.