A post card produced by Audio-Visual Designs of Earlton, New York featured this view of Boston & Maine R-1d 4-8-2 No. 4113, which N. D. Clark snapped at Worcester, Massachusetts in 1946. The five locomotives of class R-1d, delivered by Baldwin Locomotive Works in 1941, were the last steam power acquired by the B&M. Like the preceding R-1 subclasses and the class P-4 Pacifics, these engines received names suggested by school children in a contest; No. 4113 was the Black Arrow.

This final order of Baldwin 4-8-2s had a locomotive weight of 415,200 pounds and featured the fourteen-wheel PT tender. With 73-inch drivers and sustaining 240 p.s.i. of boiler pressure, these engines had 28x31-inch cylinders and mustered 67,900 pounds of tractive force. They had 79 square feet of grate area, 4510 square feet of evaporative heating surface, and 1925 square feet of superheating surface. in 1944 the Lehigh & Hudson River Railway received three 4-8-2s from Baldwin that were virtually identical to the B&M's R-1d class, including the 14-wheel tenders. In 1947 the B&M sold the first thirteen class R 4-8-2s to the Baltimore & Ohio, but No. 4113 was the fourteenth locomotive in the series and was not included in the sale. Regrettably, no representatives of this fine design remain.