State Grid Suqian Power Supply Company effectively completes the hidden danger treatment of 'three-span' lines

On Aug 28, personnel from the State Grid Suqian Power Supply Company were engaged in the dismantling of conductors and ground wires associated with the 110 kV Liji II 7K74 Luji branch line, specifically at towers No 13-16, which cross over the Xuyan Expressway.

The "three-span" lines primarily denote routes that cross over highways, high-speed rail lines and critical power transmission channels. The safety of these lines bears significant implications for public safety. In the event of incidents such as tower collapse, line breakage, or string drop, they could potentially trigger substantial societal and reputational repercussions.

Since 2016, the State Grid Corporation of China has accelerated the management of hidden dangers in the "three spans" in Suqian, Jiangsu province, and has updated the categories of hidden dangers annually. Consequently, the State Grid Suqian Power Supply Company has conducted a thorough assessment of the hidden dangers associated with the "three spans" and has developed targeted measures for each tower to eliminate these dangers.

On Aug 28, the guide and ground wires of the 110 kV Liji II 7K74 Luji branch line, spanning from poles No 13 to No 16, were successfully removed across the Xuyan Expressway in Suqian. This marked the efficient resolution of hidden dangers in the "three-span" line by the State Grid Suqian Power Supply Company.

The current hazard mitigation project involves the removal of a decommissioned line. As the line spans the Xuyan Expressway, it requires the temporary closure of both traffic lanes, making coordination of an extended shutdown period challenging. The company engaged in extensive negotiations and technical reviews with several entities, including the Xuyan detachment of the Jiangsu Provincial Highway Transportation Law Enforcement Corps, the highway management team of the Suqian City Public Security Bureau Traffic Police Detachment, the Suqian-Huai'an-Yancheng Expressway Management Co Ltd, and the Suqian Sunshine Power Transmission and Distribution Engineering Co Ltd. Ultimately, construction was scheduled to commence on Aug 28, with the removal process starting two months earlier than originally planned.

In the process of demolition, the construction personnel made preparations a day in advance. After receiving the highway closure order, the demolition was completed on site in four minutes, and the road was reopened to traffic after only six minutes of closure.