When the Padma Bridge opened to traffic in Bangladesh on June 25, 2022, Wang Zhongmei was not at the ceremony, despite playing a pivotal role in its construction.

Instead, she watched it on television at her home in Jiujiang, Jiangxi province.

On the screen, vehicles began crossing the long-awaited bridge over the Padma River.

For many Bangladeshis, it was a dream bridge.

For Wang, it was a project that had started years earlier with steel pipe piles, welding trials and repeated tests inside a factory.

"It has finally opened. I feel very proud," Wang said at the time.

Chief welder at China Railway Jiujiang Bridge Engineering Co, Wang had worked on welding tests for the steel pipe piles used in the bridge's piers. The first steel pipe pile for the Padma Bridge involved her welding tests. The challenge was not just to join two pieces of steel. Each pile was more than 120 meters long and made from sections of steel pipe about 3.2 meters in length. The pipe walls were about 6 centimeters thick. Once completed, the piles would be driven into a soft underwater foundation and left to face the current, mud and long-term pressure.

Before that could happen, Wang and her team had to answer practical questions one by one. Could the ultra-thick pipe walls be fully welded through? Could the sections be joined quickly and accurately on water? Would the seams hold under conditions no welder could see once the pile was buried?

For more than half a year, Wang and members of her team repeated welding trials in the factory. They worked on the process for on-water positioning and fast connection of the steel pipe piles, helping support construction of the Padma Bridge — a key project of the Belt and Road Initiative.

This is where much of Wang's work ends up: hidden from public view, inside steel, under a bridge — beneath traffic. "We must think of passengers. Railway safety is no small matter," Wang said.

Her connection with bridges began at home. Her father was also a welder and took part in the construction of the Jiujiang Yangtze River Bridge. After graduating from a technical school in 2001, Wang joined the same industry.

Welding meant heat, smoke, sparks and long hours in cramped spaces. Wang said of her first day on the job: "My eyes were all swollen with the heat and light when I finished my first day."

Seven female workers joined the trade around the same time. One after another, they changed jobs. Wang stayed.

At first, staying meant learning how to hold the torch steady, ready the molten pool, and keep each movement even. Later, it meant turning experience into solutions. In welding steel plates 16 to 28 millimeters thick, she changed a traditional double-sided groove welding process into a single-sided one, helping control deformation and improve efficiency. The process became known within the company as the "Wang Zhongmei welding method".

Over the years, Wang has taken part in welding work and preliminary welding tests for more than 60 major bridges, including the Wuhan Tianxingzhou Yangtze River Bridge, the Nanjing Dashengguan Yangtze River Bridge, and the Shanghai-Suzhou-Nantong Yangtze River Road-Rail Bridge, also known as the Husutong Yangtze River Bridge.

In 2013, she became the leader of the first women's welding team on China's bridge-building front. Two years later, the company established the Wang Zhongmei Model Worker Innovation Studio, where she and her colleagues carry out welding research and train younger workers.

"My apprentices have started taking apprentices of their own," Wang said.

A bridge may appear to be finished when it opens to traffic. For Wang, it also carries the memory of tests repeated in a workshop and sparks falling in the heat.