Diesel Locomotive Engine

a diesel-type internal-combustion engine installed in a locomotive.

Diesel locomotive engines differ from stationary and marine engines in the variety of their operating modes and in the frequency with which the modes change. These factors are caused by the varying weights of trains, changing conditions on sections of railroad lines, stops, and varying climatic conditions (for example, air temperatures range from –50° to 45°C). The specific effective fuel consumption of diesel locomotive engines ranges from 204 to 230 g per kilowatt-hour (150–170 g/hp-hr). The power output of engines installed in main-line locomotives reaches 4,400 kilowatts (approximately 6,000 hp); there is a present trend to higher outputs—up to 6,000 kilowatts (approximately 8,100 hp).

The engines are characterized by high compression with supercharging relative to the brake mean-effective pressure: p_e = 1.6–2.0 meganewtons per m² (16–20 kilograms-force per cm²). The specific weight relative to effective power is 3.3 to 22 kg per kilowatt (2.4–16 kg/hp); maximum crankshaft speeds are 750 to 1,500 rpm. The engines have six to 20 cylinders arranged in one or two rows or in a V-shape, depending on the power output. The ratio of the piston stroke to the diameter of the cylinder bore ranges between 0.9 and 1.4. Power increases are achieved mainly by increasing the supercharging pressure to 0.3 meganewtons per m² (3 kilograms-force per cm²) and by providing interstage cooling of the supercharged air. Engines with outputs between 550 and 1,400 kilowatts (750–2,000 hp) are used as switch engines.

Diesel locomotive engines are characterized by a high degree of automation, achieved by the use of governors for engine speed and power, regulators for water and oil temperatures, and devices to prevent abnormal operating regimes. The operating time for such engines prior to the first major overhaul is up to 35,000 hr, which corresponds to a run up to 1.2 million km.