If something goes wrong with a high-voltage line dozens of meters up in the sky, expect veteran wireman Zhao Wenwu and his team to swing into action.

Zhao Wenwu climbs down a rope ladder after finishing his work on the high-kilovolt lines in Dalian, Liaoning province, on Wednesday. Zhang Xiaomin / China Daily

On one recent morning, they climbed up an electrical tower to replace a broken spacer on 500-kilovolt lines about 40 meters overhead.

It was near a transformer substation in Dalian, Liaoning province.

"This work can be lethal," said Zhao.

"We work without switching off the currents so as not to disrupt the normal power supply."

"But we have strict rules and instructions for every procedure. Abide by them and it's safe," he said.

Zhao, 44, has been working with high-voltage lines for 22 years.

His parents worked for a power plant in Dalian, and Zhao became a student at a local technical school in 1985.

Three years later, he graduated and was assigned to check and repair high-voltage lines. At school he had only learned about working in a power plant.

"At that time, students had no choice. We had to do the work we were assigned to do," Zhao recalled. "But that was not bad for me. Working in the field suits me well."

In the beginning, he repaired lines when the current was shut off.

Then in 2002, Zhao was transferred and started to work without cutting off the current.

He will never forget the first time he grasped a high-voltage line.

"I saw veteran electricians do it many times. The high-voltage electricity lines cause hisses that frighten anyone coming close. But there was no time to hesitate. When my hand reached a safe distance, I had to grab the wire as soon as possible. Otherwise, there was risk of getting electrocuted," he recalled.

For the first time, he realized the danger of his job.

Every time he completed a task, he sighed with relief and told himself "Well, I've come down to the ground safely, again".

Zhao's wife also worries about his safety, especially when he comes home late or goes out to work in the middle of the night. So Zhao tries not to let his family know many details of his work.

Zhao said the danger can be controllable.

He wears a special working uniform to walk on the lines with his hands on the upper lines and feet on the lower ones.

"The uniform becomes a part of the lines. The currents flow through the clothing. Hidden in it, the body is insulated," he explained.

Yao Hailin, Party head of the power transmission work area of Dalian Electric Company, said Zhao's squad is like the special force of a field army.

"Their work is irreplaceable. Among all the 51 workers in our work area, only the eight members at Zhao's squad can work without cutting off electricity. If needed, they must arrive at the spot as soon as possible even if it's freezing at midnight," he said.

"In addition, walking on the lines is quite exhausting. The lines are swaying. It's not easy to keep your balance. For people more than 40 years old, even if they can climb up the tower, they don't have enough strength to do the work," he added.

With his years of experience, Zhao now mainly works as an instructor.

Nie Lu, 26, is one of Zhao's best students. That morning under Zhao's instruction, Nie walked more than 100 meters on the lines to change the broken spacer, which took him nearly three hours.

When he got down to the ground, he collected his tools and instruments, showing not even a sign of fatigue.

"Sometimes we work on the lines for more than eight hours. Compared with that, this is a piece of cake," he smiled.

In Nie's eyes, "master Zhao" is not only a reliable veteran but also a smart person.

"It can be seen from his great memory. In our spare time, we often play cards. But we can seldom beat him because he can remember three sets of poker cards," said Nie.

Zhao and his team have made many innovations to improve their work, and he intends to fly model planes to take a rope ladder to the lines.

"If successful, we will climb to the lines directly and no longer need to walk on the lines," Zhao said.

Contact the writer at zhangxiaomin@chinadaily.com.cn