Trains rely on locomotives equipped with power machinery (commonly known as locomotives) to draw carriages and run on the railway. Trains are an important part of modern transportation. In addition to transporting passengers, trains are also the main means of transportation for long-distance transportation of goods, with the advantages of large load capacity and low transportation cost. Besides, in large coal mines and factories, trains are also used to complete internal transportation tasks. \ x0d \ x0d \ train has a history of 100 years. The earliest train was made by Stephenson, an Englishman, in 18 14. By 1825, the "Power" 1 locomotive he made created the highest speed of land travel at that time, 24 kilometers per hour. In the next few decades, the train gradually became an important means of transportation. European countries and the United States began to build railways on a large scale, and mankind entered the railway era. The appearance of trains and railways enables people to travel long distances more quickly, and it is easier to obtain needed materials from far away places and transport products to far away places for sale, which greatly promotes the development of production and improves people's living standards. \ x0d \ x0d \ In the early days of train development, the power of the train was mainly provided by the steam engine on the locomotive, and the locomotive had to carry the coal and water needed by the steam engine. This kind of locomotive is called a steam locomotive. With the development of the times, modern trains no longer use bulky and inefficient steam engines, but use internal combustion engines or motors to generate electricity. This kind of locomotive is called diesel locomotive and electric locomotive respectively. \ x0d \ x0d \ diesel locomotives include diesel locomotives and gas turbine locomotive locomotives, both of which carry fuel by themselves, use internal combustion engines to generate power, and pull trains forward through transmission devices. Electric locomotives rely on transmission lines built along the rails to transmit electric energy and use motors to generate electricity, which has the advantages of convenient control, high speed and little pollution. In addition to running on the ground, electric locomotives are also used for traction of underground railways built in some cities. \ x0d \ x0d \ Railway is specially built for train operation. Rails are laid on sleepers, which can transfer the pressure generated when the train passes to the ground evenly. The cross section of the track is I-shaped, which not only has enough strength, but also saves materials. The steering of the train is also guided by the rails. \ x0d \ x0d \ The first steam locomotive in China was built in Tangshan in 188 1 year. The early railway builders in China, represented by Zhan Tianyou, made immortal contributions to China's railway transportation. At present, China can design, produce and maintain all kinds of locomotives by itself, ending the history of manufacturing steam locomotives in 1988 and entering the era of traction trains with diesel locomotives and electric locomotives coexisting. \ x0d \ x0d \ At present, the trains in the world are mainly drawn by diesel locomotives or electric locomotives, and the running speed of the trains is greatly improved. The most advanced maglev train uses magnetic force to suspend the train on the track, and its top speed can reach more than 500 kilometers per hour, and it will continue to improve. Although automobile and air transportation have made great progress today, trains still occupy a position that cannot be ignored.