Beijing, Nov 25 (IANS): China's first high-speed rail line in the country's freezing high-altitude regions is ready for service, said authorities.

The railway linking northeastern Chinese city of Harbin and port city of Dalian will start service Dec 1, marking the world's first long high-speed line running through regions with extremely low temperatures during winter, the Ministry of Railways announced Saturday.

With speeds of up to 350 km per hour, the 921-km railway will go through the country's three northeastern provinces -- Heilongjiang, Jilin and Liaoning -- as part of the planned Beijing-Harbin high-speed railway.

It is one of the four north-south lines China aims to finish by 2015.

Unlike current high-speed lines in operation, temperatures along the new route are likely to plunge to 40 degrees Celsius below zero.

With snow and frozen land, the inclement climate conditions created numerous stumbling blocks during the construction process.

Zhou Li, an official in charge of technology, said the ministry conducted 22 research projects to target technology obstacles, including steady monitoring of the track condition and overhead contact system.

He said that from September to November, the line has undergone 3,030 trial tests in various weather conditions, ranging from normal, low temperature, to heavy snow and even blizzards.

"Test statistics show safety can be guaranteed even if the trains are running at 300 km per hour in winter," he said.

To minimize the impact of extreme weather on the operation, the ministry has created emergency plans, such as speed reductions and temporary halts, to ensure safety.

The rail project being the first of its kind, the ministry is being cautious by adopting two different schedules. The speed during the winter season (Dec 1 to March 31) will be 200 km per hour, with the summer period (April 1 to Nov 30) speed being 300 km per hour.

The ministry said ticket prices will vary depending on the schedule.

With 23 stops along the route, including that at the industrial base Shenyang city, the line will cut travelling 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, according to a five-year plan on China's transport system approved by the State Council, China's cabinet.

China currently has more than 6,800 km of high-speed railway lines that run at a speed above 200 km per hour. The total length is expected to reach about 18,000 km by 2015.