Ratings of diesel-electric locomotives

THE DIESEL-POWERED locomotive has emerged as one of the most efficient and economical forms of motive power available to industrial and railway users, ranging in size from 100 to 8,000 horsepower. This versatility is due largely to the electric transmission system by means of which the relatively constant torque of the engine is transformed to the varying torque required at the driving wheels for effective utilization of full engine horsepower over the operating range of the locomotive.