(BEIJING, August 31) -- As the result of the 12-hour successive work of over 60 welders, the welding of 26 joints on the vertical walls of the main structure of the "Bird's Nest" finished at 13:00 pm today, marking the end of the welding process of the steel structure of the National Stadium, the main stadium of the XXIX Olympiad.

The welders have overcome two major technical difficulties: the strict temperature requirements and a large number of welding seams. As the effective control of temperatures concerns the safe operation of the steel structure, the welding work proceeded under temperatures of 15-23 degrees Celsius. With a total length of 600 linear meters, the whole structure had four welding seams and 128 joints. It took three periods to wind up all of the welding.

More than 100 senior welders and over 100 soldiering sets joined the last combat. To ensure ideal weather conditions and temperatures, 60 on-spot temperature monitoring points and meteorological monitoring stations were set up to watch the change of air and surface temperatures of the steel structure. The Beijing Meteorological Station also designated its specialists to guide the on-spot monitoring work. To ensure welding quality, each of the seams underwent crack detection.

The welding process, conducted on August 26, 29 and 31, consumed a total of 2,000kg of welding rods.