The B&M's class S-1a 2-10-2s had 61-inch drivers, 29x32-inch cylinders, and 190 p.s.i. of boiler pressure. With an 80-square-foot grate area, they had 4646 square feet of evaporative heating surface and 1145 square feet of superheating surface. Between 1936 and 1947 six members of the S-1a class were sold to the Maine Central, but whether this engine was one of that group is unknown. This view of No. 3015, featuring a Coffin feedwater heater and a booster on the rear tender truck, dates from May 5, 1934 and was probably snapped somewhere in Middlesex County, Massachusetts as the locomotive was taking on water. Carl Weber supplied the image.