What is electrified railroad?

Electrified railroads are railroads with traction power systems that use electric trains as traction power for the trains.

When railroads were first invented, they were powered by steam locomotives. Until 1879, the world's first electrified railroad was built in Berlin, Germany. Later, with the development of science and technology, electrified railroads appeared in many countries. By the 1980s, the total mileage of electrified railroads in the world had reached 165,000 kilometers, accounting for 13% of the total mileage of the world's railroads. And Germany, Japan, France's electrified railroad has accounted for the country's total railroad mileage of 1 / 3, but can complete the capacity of 3 / 4.

Obviously, electrified railroads than the traditional steam or diesel-powered railroads, compared with the obvious superiority.

First, it has a large transportation capacity. Generally speaking, electric locomotives are very powerful. Generally about 1 times larger than the internal combustion engine or steam locomotive. The power is large, the traction force is large, you can increase the traveling speed, improve the transportation capacity. Second, its energy consumption is more economical. The thermal efficiency of electric locomotives is generally 20% to 26%, which is higher than 20% of diesel engines and 6% to 7% of steam engines. Third, it has low operating costs. It is because of the low energy consumption of electric locomotives, maintenance and repair costs are low, so that the operating costs down, especially in long-distance transportation is more obvious. Fourth, it is good working conditions, noise, pollution is greatly reduced, easy to operate.

However, electrified railroads generally require greater investment, so it is not as common as the traditional diesel and steam locomotive-powered railroads in the application.

Electrified railroads use electric locomotives for power, so where does its power come from? Electric locomotives are not fitted with generators; their power is provided by the electric traction power system.

This power supply system consists of traction substations and contact networks. Electricity from the power plant is transformed by the traction substation to send power to the contact grid erected over the railroad, while the electric locomotive draws power from the contact grid, which is somewhat similar to a tram running in a city, and then drives the electric locomotive forward.

Traction power is supplied in both DC and AC systems. In view of the DC system of power supply voltage is difficult to continue to improve, has been replaced by the trend of AC system. China's electrified railroads have adopted the AC system from the beginning.

Construction of an electrified railroad, along the line to build a lot of traction substations, single-line railroad every 60 kilometers to be built, double-line railroad every 40 kilometers to be built. This also shows that the cost of electrified railroads is huge.

China built the first electrified railroad is completed in August 1961 Bao Cheng line of Baoji to Fengzhou section. By 1984, a total of 3,500 kilometers of electrified railroads had been built.

The newly paved Nankun Railway is called the dream of the century by the people of the southwestern part of the country. South Kunming Railway from an altitude of 78 meters of the Nanning Basin rose to an altitude of more than 2,000 meters of the Yunnan-Guizhou Plateau, the great difference in height, in the history of China's railroad construction is unparalleled. Also, the entire line formed between the ditch beams, bridges and tunnels connected to the trend, the soil along the line is very complex, known as the "stratigraphic exposition", "underground labyrinth". Just for the paving of the railroad there are 258 tunnels, a total length of 194.6 kilometers; repair 476 bridges, a total length of 79.8 kilometers. Many of these bridges and special bridges have high piers, large spans and new structures that are at the leading level in the country.

South Kunming Railway, a national key project, is an important channel to communicate between the southwest and the coast of South China, is the best and most recent way to the sea in Yunnan, Guizhou and Sichuan. This railroad, from December 1990, 60,000 railroad builders to overcome the difficulties and dangers, and finally paved, rounded out the people of Southwest China's "dream of the century".