CHANGCHUN - China's high-speed trains that will travel across the country's frigid northeastern regions are designed to withstand sharp changes in temperature, a chief engineer said Wednesday.

The country's first cold-proof high-speed trains are expected to run from Saturday and any problems with sharp changes in temperature that once forced Eurostar to halt services in 2009 look to have been solved.

The trains, to withstand minus 40 degrees Celsius temperature, will travel 921 kilometers between Harbin in Heilongjiang province and Dalian in Liaoning province.

CNR Changchun Railway Vehicles Co Ltd, a subsidiary of the country's major train maker China CNR Corp, developed the cold-proof train cars.

Kong Feng, a senior engineer with the company, said his team had solved the problem Eurostar trains once encountered, which is considered a major challenge for developing cold-proof trains.

In December 2009, the Eurostar service was brought to a halt by the snow and cold temperatures in northeastern France.

Experts believe snow got into the power car and melted after the trains entered the warmth of the under-sea tunnel beneath the English Channel. This caused electrical breakdowns.

Kong said the key lies in optimizing the condensate water-proof system of the train while adding highly advanced anti-condensate water equipment on the exterior.

Kong said in test runs conducted in October, the CNR train cars beat snow storms and extremely-low temperatures.

The maximum speed hit 385 km per hour while the train was able to maintain 350 km per hour, he added.

The Ministry of Railways earlier said the trains on the Harbin-Dalian route will adopt different speeds -- 200 km per hour during winter (Dec 1 to March 31) while traveling 300 km per hour in summer (April 1 to Nov 30).

With 23 stops along the route, including the renowned industrial base Shenyang city, the line will cut traveling times between the two cities to about four hours from nine hours.

China aims to create a high-speed railway backbone network featuring four east-west lines and four north-south lines by the end of 2015.

The country now has more than 6,800 km of high-speed railway lines on which trains run at a speed of 200 km per hour or above. The length of the high-speed lines is expected to reach 18,000 km by 2015.