diesel

Diesel locomotives became the standard for railroads by the late 1960s, largely replacing steam power. This shift was driven by the need for increased efficiency and lower operating costs, especially in the face of competition from other transportation modes.123

Diesel locomotives offer several advantages over steam:
* Reduced Maintenance: They require significantly less downtime for servicing, allowing for longer operational periods.123
* Higher Thermal Efficiency: Diesel engines are about four times more efficient than steam engines, using less fuel energy.123
* Improved Performance: They can accelerate trains faster, maintain higher speeds, and cause less track damage.123

Diesel-electric locomotives function like electric locomotives but carry their own power source, avoiding the need for external electrification infrastructure. While powerful, their horsepower output is limited by the diesel engine, making them less ideal for very high-speed passenger services compared to electric locomotives. The core principle of a diesel engine involves compressing air to raise its temperature, then injecting fuel that ignites due to the heat.123