Exactly why did the diesel-electric locomotive replace the steam locomotive?
A. Thermal efficiency of a diesel is about 30%, compared to 6-7% for a steam locomotive. The diesel is therefore much more fuel efficient. B. Diesels develop maximum horsepower and efficiency over a wide range of speeds. Steamers have a very narrow speed range in which they reach full efficiency. C. Diesels can be operated in multiple units(MU) under only one set of controls. This means that 1 unit can control many other units. This allows once crew per train and greatly reduces labor costs. D. Dynamic Braking allows good speed control on downgrades and reduces brake repairs. Longer trains are also allowed with better speed control. E. Maintenance costs are very low in comparison to steamer. Diesel locomotives have an availability of 90% or better, compared to 30-40% for the average steamer. Standardized and modular design played a major role in the diesel’s advantage over steam. A diesel could replace about 10 steam locomotives. F. Fewer fuel and water stops.A diesel requires little w
