Grid Workers like Spider-men “Weave” the Net in the Air!

HIMALAYAL - SHANGHAI - CHINA

The Jiuquan-Hunan ±800kV UHVDC transmission line passes through four provinces of Gansu, Shanxi, Hubei and Hunan, and one city-Chongqing. The full length of transmission line is 2383km. The Jiuquan - Xiangtan ±800kV converter station was newly built with an increase of 16MKW converting capacity. The rated power transmission capacity will be 8MKW with a total investment of ¥26.2m. The transmission line is expected to complete and run in 2017.   

The Shanghai–Kunming high-speed railway passes through five provincial capitals of Hangzhou, Nanchang, Changsha, Guiyang and Kunming, and one municipality - Shanghai. The total length of railway line is 2266km and the target cruising speed along the line is 300 kilometers per hour with a top speed of 350 kilometers per hour possible under optimal conditions. It is the longest east to west high-speed railway and passes most provinces.  


In order to guarantee normal operation of high-speed trains, the construction of Jiuquan-Hunan ±800kV UHVDC transmission line starts in the wee hours. 

Due to high frequency of train service during the daytime, workers have to perform construction only between 0:00am and 4:00am when all high-speed trains halt for maintenance. The construction time is short, however, the wire built in the project has the largest sectional area in the world, up to 1250SQMM. Meanwhile, it is the first time to set up large-section wires over high-speed railway within Hunan province, so there is no much experience to refer to.   

These two fully-enclosed suspension closeups with 60m long and 12m wide are built in the air prior to line construction. The distance between suspension closeup and railway line is 6.5m, which poses a major challenge to construction material and technology.    


Tang Chunpu is a worker in charge of construction on site. “Although we have a set of developed scheme, it is indeed the first time for us to make electric lines cross over so important Shanghai–Kunming high-speed railway; besides, we are pressed for time and part of tools and schemes cannot be used here without changes. In order to accelerate the speed, we use the hand-held line-throwing appliance rather than popular UAV to place guide lines. The line-throwing appliance can throw several guide lines at the same time and the throwing distance is up to 230m, which improves the working efficiency and simplifies operation process,” he said.  

The installation work of suspension closeup device lasts from 23th September to 24th. The constructors like spider-men “weave” two wide suspension closeups in the air above the railway, ensuring the safety of construction site. With the completion of suspension closeup installation work, constructors officially began the construction of lines in the small hours.    

As two “giants” - No.7140 tower and No.7141 tower went hand in hand at 3:00am 29th September, an urgent construction task lasting for 7 small hours completed smoothly.