Feature: A top gun's story of Hong Kong's bridges

HONG KONG, June 16 (Xinhua) -- In China's Hong Kong, there is probably no one who knows better about bridges than Lau Ching-kwong.

Starting as an assistant engineer in the 1960s, Lau has been in the bridge construction business for more than half a century and has overseen the construction of many world-class bridges in Hong Kong. He has also won the highest award for bridge engineers in China.

Famed as the "top gun of bridges" in Hong Kong, Lau calls the island-rich region a museum of modern bridges.

An ideal first stop to appreciate the rich variety of Hong Kong's bridges would be Tsing Yi, northwest of Hong Kong Island, and one of the most densely populated islets on earth.

For Lau, Tsing Yi is special for being connected with so many state-of-the-art bridges: it has Tsing Yi Bridge and Tsing Tsuen Bridge in the east, Tsing Ma Bridge in the west, Ting Kau Bridge in the north, and Stonecutters Bridge in the southeast.

It is also a memory-jogging place for Lau as, among other personal reasons, he served as the chief engineer during the construction of the massive Tsing Ma Bridge in the 1990s.

The 1,377-meter construction is a major midway link to the Hong Kong International Airport, and the span is the longest of all bridges in the world carrying rail traffic.

"Before Tsing Ma Bridge, building such a long dual-purpose bridge in a typhoon-prone area has never been done in the world," Lau said.

The biggest challenge in building a cross-harbor bridge in Hong Kong is how to resist the wind. With a large span, the bridge has to be long enough. And to ensure the passage of large cargo ships, the bridge has to be high enough.

Lau and the team visited the countries with a developed bridge industry, seeking inspiration for the design. "We checked all their bridges that are over 500 meters long," he said.

After many experiments, they adopted the innovative design of using 5-meter-wide ventilation holes to enhance the bridge's stability against the wind.

To guarantee the lasting operation of the bridge, Lau, who was working on his doctoral course at Tsinghua University while building the bridge, participated in developing a bridge health monitoring system. His doctoral thesis was also centered on this subject.

"Tsing Ma Bridge's 'physical indicators' are so far quite good," Lau said with pride.

The Stonecutters Bridge is adjacent to the Hong Kong container terminal and is of great significance to the port logistics industry.

The main bridge is 1,018 meters long and was the second-longest cable-stayed bridge in the world when it was completed in late 2009. At 73.5 meters above sea level, the bridge is also one of the tallest bridges in the world, which allows the unimpeded passage of oversized cargo ships.

After its completion, the Stonecutters Bridge has become one of the new landmarks of Hong Kong, and its majestic appearance has attracted the public to visit and watch the bridge, making it a popular photo spot.

Bridges have witnessed Hong Kong's development as an international shipping and trade center, as well as its new advantages under the national development strategies.

The Hong Kong-Zhuhai-Macao Bridge is the world's longest bridge-tunnel combined cross-sea passage, a landmark project in the Guangdong-Hong Kong-Macao Greater Bay Area. Lau was involved in the construction consulting work of the Zhuhai section of the immersed tube tunnel.

As the world's longest immersed tube tunnel under the sea, its construction difficulty lies in guaranteeing no water leakage from the pipeline interfaces, which is a world-class achievement.

"It is amazing," Lau said. "The Hong Kong-Zhuhai-Macao Bridge has impressed the world."

By participating in the project, Lau witnessed China's rising prowess in bridge building, as well as its overall strength.

He believes that as China's strength in bridge-building develops and Hong Kong becomes increasingly integrated into the national development picture, Hong Kong bridge builders are ushering in the best of times.