The SAL operated a total of ten 2-6-6-4 articulated locomotives which were built in two batches of five by Baldwin in 1935 and 1937. Although they were smaller than the Norfolk & Western class A, they still weighed 480,000 pounds without a tender and 790,200 pounds in total. The grate measured 96.3 square feet (8.95 m²) and the firebox had a surface of 515 square feet (47.85 m²), including two thermic syphons and a long combustion chamber. The tubes and flues totaled 4,998 square feet (464 m²) and the superheater 2,397 square feet (223 m²).