operates 67 pairs of CRH380BG type alpine EMU trains. These have been specially modified for the Hada railway which must cope with temperatures as low as in winter. Extra insulation has been added within the skin of the carriages and even the vacuum toilets have been modified to operate in this extreme cold. The track has been specially designed to cope with extremes in temperature. In winter, the temperatures on the route can fall to while in summer they can reach . Heavy snowfall in the area is also common during winter. This large change in temperature can cause frost heave. As the water in the ground freezes in winter, it expands. In summer the ice melts and water drains causing shrinkage. This creates distortion on the ground surface that ordinary high speed railway lines could not cope with. To combat frost heave, 70% of the line is constructed above the ground surface on viaducts. During construction, about 20 percent of the track that had been built directly on the ground had to be redesigned and rebuilt due to frost damage. This delayed the opening of the line by about a year. Stations See also Asia Express South Manchuria Railway, about the early history of the railways in the same corridor Beijing–Harbin high-speed railway Beijing–Shenyang high-speed railway Panjin–Yingkou high-speed railway References High-speed railway lines in China Standard gauge railways in China Rail transport in Heilongjiang Rail transport in Jilin Rail transport in Liaoning 2 Railway lines opened in 2012