FUTURE TRENDS IN LOCOMOTIVE DESIGN IN NORTH AMERICA

Except for a few limited production experimental models, the maximum horsepower available on production versions of locomotive units remained between 3,000 and 4,000 horsepower from 1965 until 1994 - about 29 years. Now, there is some competition on increasing the horsepower available per unit and there is more competition on traction control to improve the amound of tractive effort available from a locomotive. The focus in this discussion is on the railroad industry's need for more horsepower and more tractive effort, for higher operating speeds and for pulling larger loads. The increases in horsepower may be useful for fast service, such as intermodal operations, and for improving the capacity of rail lines, as trains will be able to get out of the way a little more quickly if they have higher horsepower. Higher tractive efforts will be more useful in pulling large unit trains of bulk commodities. There has been some concern that the 5,000 and 6,000 horsepower units may not be able to make effective use of all of their horsepower, due to the fact that they may not have sufficient tractive effort capability to be able to use all of that power in starting a large load. However, there are plans for a unit that will not only produce 6,000 horsepower, but will produce twice the tractive effort of the SD-40-2 units, allowing for one replacement. The author mentions other new models that are being introduced. He then focuses the discussion on why railroads would want such capability in their locomotives. Why would they want higher horsepower? Why would they want higher adhesion? What advantages will it provide for them?