Baltimore & Ohio class T-3

The T-3 was the last class of 4-8-2 “Mountain” locomotives built for the B&O. The 40 locomotives were ordered to cope with the increased wartime traffic and were numbered 5555 to 5594. Compared to the few earlier Mountains built for the B&O, they were lighter and had smaller drivers with a diameter of only 70 instead of 74 inches. The 40 locomotives were built in several batches in the railroad's own Mount Clare shops between 1942 and 1948. These batches were designated T-3, T-3a, T-3b and T-3c and differed in some details. Apart from different tenders, some had no roller bearings at all, some had them on all axles and some only had them on the carrying and tender axles. Additionally, their fireboxes differed in the number of thermic syphons and circulators. The last ones were retired in 1960.