MTH - Premier Diesel Locomotives - AC4400cw - O Scale 3 Rail

From the dawn of dieselization through its first six decades, virtually every American diesel locomotive used DC traction motors. By the early 1990s, however, a series of technological advances allowed designers to tap the inherent superiority of AC traction - namely, the ability of an AC motor to start a heavier load than a DC motor, with the same prime mover. The superior adhesion of AC power touched off a new horsepower race because, with the same number of wheels, AC traction could put more horsepower on the rails.