Contrary to the popular impression, the diesel engine has a later origin than the electric engine.
Werner Van Siemens, a German engineer developed the first electric railway engine in 1881. The technology at that time used both the rails to carry the current, but since then the overhead electric wires has become the norm for safety reasons. The invention of the Diesel Engine followed 12 years after the invention of the electric engine, by Rudolf Diesel, another German engineer.
Electric Locomotive vs Diesel Locomotive Efficiency
According to O-Keating's The Electric Engine, the major advantage of the electric locomotive engine over diesel engine is that electric engine uses a rather simple and straightforward technology. The electric engine pulls power directly from the power grid and requires only a transformer and a regulator to bring down the power to acceptable levels. Diesel engines on the other hand uses diesel to produce energy, which is then transformed into electricity, and then again into kinetic energy, making them only around 40 percent efficient for the diesel consumed.
IRFCA's Diesel vs Electric debate however argue that the total cycle efficiency of electric engine from power plant to wheels of the engine is much less than the diesel loco.
Electric Locomotive v/s Diesel Locomotive Technology
Electric engines are lightweight, constituting only motors and wheel axles, and have almost no moving parts. Diesel engines on the other hand have a large number of moving parts such as pistons, valves, turbines, and chains. Electric engines are therefore easier to maintain whereas the moving parts of a diesel engine require constant maintenance.
The lightness of the electric engine contributes to lesser wear and tear of the tracks in comparison with the diesel engine. Diesel engines however are capable of 10 percent higher load hauling capability.
Electric Locomotive v/s Diesel Locomotive Speed
The simple nature of the electric engine makes them efficient and powerful. Electric engines do not produce much heat and noise, meaning that most of the energy produces converts into foreword motion. Diesel engines, on the other hand waste generate much heat and noise, diverting the energy away from forward motion.
Electric motors have the ability to produce as much torque as the power supplied. The primary disadvantage of the diesel locomotive engine is the amount of electricity the diesel engine generates limiting the power supply, making such engines incapable of attaining higher speeds.
The speed record for an electric locomotive engine is 320 mph, and for a diesel locomotive engine 148 mph.
Electric Locomotive v/s Diesel Locomotive Commercial Consideration
A major commercial consideration for railways to prefer electric locomotive engines to diesel locomotive engines is cost and availability of diesel. Diesel is an expensive non-renewable fuel source whereas electricity is a cheaper and infinite source of energy.
The major advantage of the diesel locomotive engine is its ability to work under all conditions and at all terrains, and the major disadvantage of the electric locomotive engine compared to the diesel locomotive engine is the requirement for power supply in the form of overhead electric lines. The capital cost of laying 5 to 6 kilometers of traction wires is equivalent to the cost of a new diesel locomotive.
In addition to the cost and difficulties of installing overhead power lines and sub-stations to supply power, the possibility of disruption of train services is always a live concern for the following reasons:
- power disruption
- damage to the overhead lines or posts supporting the electric lines
- The pentograph on top of the locomotive not making proper contact with the electric wires
Conclusion
Diesel locomotive is in fact an Electric Locomotive carrying its own powerhouse. While the earlier versions of the diesel locomotives were indeed inefficient, today’s modern diesel locomotives with Electric transmission have all the benefits of modern technology.
The International Railway Journal of March 2000 indicates that the future of the locomotive lies in a simple fuel cell that uses Hydrogen from fuel to combine with Oxygen and produce electricity. Diesel engines can easily upgrade to such a new technology by replacing the engine with the fuel cell, and in such as scenario, the overhead wires used for electric engines would become redundant.
Nayab Naseer - Nayab Naseer is a Post Graduate in Human Resource Management with 10+ years of corporate work experience. He is an extensive writer ...
Join the Conversation