EMC TA

The Chicago, Rock Island and Pacific Railroad introduced its first diesel-powered streamliners, The Rocket, in 1937. The first six Rockets were three- or four-car stainless-steel semi-articulated trainsets built by Budd Company. They were powered by six identical locomotives, #601-606, especially built for the Rock Island by Electro-Motive Corporation. These were classified as model TA—the T indicating Twelve hundred hp (890 kW), the A indicating an A unit (cab-equipped lead locomotive).

The TAs were unique in that they were the only small, lightweight streamliner motive power to be truly separate locomotives. It shared this trait with the roughly contemporary EA, E1 and E2, all built in 1937, but they were all full-size locomotives intended to pull much heavier trains, while the TAs were pocket-sized, styled to match the short, lightweight trains they hauled. 1937 was very much the year that the passenger diesel locomotive evolved from the integrated streamliner. Future locomotives would follow the direction taken by the EA, E1 and E2, full-size locomotives to pull lightweight but full-size passenger cars; the TA became the blueprint for EMC's "F" series of freight locomotives, thus proving that the concept of a separate diesel locomotive had finally and fairly decisively taken hold - and that steam was doomed.