01
First attempt to "airdrop" transmission towers
Why did they choose to face the difficulties?
Wang Yi of State Grid Space Technology Co., Ltd. and his colleagues had "struggled" for many days at the disaster relief site in Fangshan, Beijing, using helicopters to transport supplies and rushed to transport many wounded and pregnant women. On the 8th, he suddenly received a notice from the company that he needed to go to Hailin City, Mudanjiang, Heilongjiang to assist the local power repair work.
Affected by the recent heavy rainfall, the Mudanjiang area of Heilongjiang suffered severe floods, and the Duoji Iron Tower of the 110 kV Haichang Line collapsed. Due to the rising water level, some damaged iron towers have become isolated islands in the water, and conventional maintenance methods are no longer applicable at this time:
First of all, the flood has not yet receded, and the river flow is turbulent. Traditional methods such as boat transportation and pontoon bridges cannot complete the cross-river transportation of large tower materials and machinery. Furthermore, the water and silt around the base of the tower is more than half a meter deep. Even if the transportation problems of tower materials and machinery are solved, the staff cannot carry out the tower assembly operation.
On the 9th, after the emergency repair unit arrived in Hailin City, it immediately carried out surveys, spreader connections and other preparations. The isolated island in the middle of the river has serious water accumulation, and artificial activities are restricted. What is even more "deadly" is that typhoon "Kanu" was heading north at that time, and it will soon bring large areas of heavy rainfall. The time left for them is only day and a half. If this window period is missed, the official power supply can only be postponed again.
They decided to use heavy-duty helicopters for the whole tower hoisting and assembly operations.
This is a very difficult operation: it is necessary to hang a nearly 3-ton iron tower and hover in the air for a long time, and the crew also needs to control the swing of the aircraft; Holes, precisely docked with the anchor bolts on the tower base...
Wang Yi said that although they have carried out many power repair missions before, they have always transported tower materials or other equipment, and the hoisting of the whole tower has never been practiced, and there is no domestic experience for reference.
"No matter how difficult it is, we have to do our best. Even if the power supply is advanced by one minute or one hour, our work is meaningful."
02
After several attempts to get in place
They completed the first whole tower hoisting in China
On the afternoon of the 9th, Wang Yi and other staff took a boat to the isolated island in the water to clean up the base of the tower. At that time, it was raining intermittently in the air, and the water in the low-lying areas was more than half a meter deep, and there was still sediment under the water. "Just walking is already very tiring."
On the other side, the staff was working on the transmission tower assembly on the other side of the river, and the helicopter was on standby, waiting for the weather conditions to allow the operation. "We have been monitoring the weather information and acted as soon as we could take off."
After the weather improved, the captain Shan Zhonghu took off and began to try to lift the 20-meter-high iron tower. Seen from the air, the coin-sized anchor bolts on the tower base are smaller than ants. He holds the joystick in his hand and carefully adjusts the angle; Staff are always ready to respond to...
The iron tower swings too much in the air, and the reverse airflow affects the ground personnel... Although they are well prepared, they have tried 3 times but failed to dock successfully. During this period, the captain had to maintain a high degree of concentration. His hand holding the joystick was even numb for a while, so the co-pilot had to take over and circle in the predetermined safety zone.
Everyone was very anxious at the time: "If the transmission tower is not erected before the next heavy rainfall, the official power supply may have to wait another week."
"I want to try again!" After a short rest, the captain made another request to Wang Yi. After discussion and judgment, they set the flight altitude within the range of 60-70 meters, and carefully communicated the details of each step of operation.
The captain approached the base of the tower again, and then slowly descended. The ground staff directed the adjustment of the position, pulled the tower with a rope when it was close to the base of the tower, and then immediately reinforced it... It took about 40 minutes, and they finally succeeded!
Wang Yi said that everyone present at the time was very excited, "This is the first time that a helicopter lifts a whole tower in China, and we really did it!"
Summing up the experience that day, the next day, they successfully completed the hoisting work of the other two base towers during the rain stop, and each time it took less than 5 minutes from hoisting to precise docking!
Wang Yi said with emotion that this may be the fastest record in the world, "This record is difficult even for us to break."
03
"Next
Go to the place where it is most needed for emergency rescue and disaster relief.”
After the emergency repair of the 3-base transmission tower was completed, the staff relayed the line repair work. It is expected that more than 22,000 residents in the surrounding area will return to normal and stable power supply this morning (12th).
Looking back on this rescue experience, Wang Yi said with emotion, "In the limited time and under the relatively harsh natural conditions, none of us gave up, nor could we give up. Everyone is very excited and proud!"
Wang Yi said that this experience has also accumulated experience that can be used for reference for the emergency repair of domestic power grids. He hopes that with the joint efforts of everyone, this kind of operation, which currently seems a bit "limited", can be applied to more scenarios to improve the efficiency of emergency repair and rescue.
At present, the rescue mission of Wang Yi and his colleagues in Heilongjiang has come to an end. In the future, they will go to the most needed places for emergency rescue and disaster relief according to the deployment of the State Grid Corporation of China.