Railway official cautions smog may disrupt chunyun rush

If there is a new wave of severe smog this winter, it is expected to affect the smooth operations of rail services during the annual Spring Festival travel rush, with services being canceled and trains being forced to slow down, a rail official said.

This year, a record 3 billion trips are expected to be made during the ongoing 40-day Spring Festival travel rush, known as chunyun.

If there is a period of continuous severe smog, it can affect the railway power supply system because pollution particulates cover up the power units and can trigger an electrical discharge, said Huang Xin, an official from the transportation bureau of China Railway Corp, news portal finance.china.com reported Saturday.

"To guarantee safety, we will increase the maintenance schedule of the trains. We will also reduce train speed if necessary," Huang added.

China's high-speed trains have good ventilation systems which can filter out some particulates. At the same time, railway departments are investigating new techniques for air filtration, Huang said.

Huang confirmed that a photo that went viral of a dirt-streaked high-speed train traveling from Shanghai to Beijing was dirtied when it passed through an area of severe pollution during the last wave of smog.

The dirt on trains is caused by air pollution, but it relates to rail speed, running distance and time and direction of travel, an employee from China railway department was quoted by Beijing Youth Daily as saying in early January.

Trains are able to run at speeds of up to 300 kilometers per hour and China has built more than 20,000 kilometers of high-speed rail lines.

According to the government's plan, the mileage will increase to 45,000 kilometers by 2030, the Xinhua News Agency said.

This year's chunyun runs from January 13 through February 21. Among the record-breaking 3 billion trips, there will be 2.52 billion road trips, 360 million train trips and 58.3 million trips by air, Xinhua reported on December 6, 2016.