Thuan Phuoc Bridge

405 meters. That is the distance between the two towers of this bridge, and between those towers not a single pier stands in the water to hold up the deck. 405 meters is nearly four soccer fields laid end to end. An adult walking from one tower to the other takes about 500 steps. The whole way, there is only wind and water underfoot, and steel cables pulling the deck up from high above.

The bridge is Thuận Phước, standing where the Hàn River runs out of the city to meet the bay of Da Nang. Of all the bridges across the Hàn, this is the last one on the way to the sea. People call it the longest suspension bridge in Vietnam. Two main cables run over the tops of the two towers, then sag down in the middle of the span, just like high-voltage power lines strung across a field. From these two big cables, many smaller cables hang down and hold the deck floating between sky and water.

There is a reason the city built a bridge like this right at the river mouth. Da Nang's bridge and road experts say the city wanted a bridge for tourism. They wanted to draw the riverbank and the seashore toward the Sơn Trà peninsula, to give people a reason to travel all the way east to look at the sea. The project also did not aim to raise the load capacity for freight trucks, because other bridges had already been planned to do that job. One engineer of long experience said bluntly that many places in the world choose to dig a tunnel to cross a wide river mouth. This city wanted travelers to see the scenery they were passing through. People in the trade also pointed to the views in Hong Kong, which gave the decision makers of the time much to think about.

But a suspension bridge at the mouth of a bay has to be designed with wind in mind. At the river mouth, strong crosswinds blow in from the sea. So the engineers had to work out carefully how the wind would slide across the deck. They even carried a small model of the steel girder all the way to China, to test how steady the deck would be in the wind. From that test, they came away with a figure for its stability.

The ground held a surprise too. To hold the ends of the cables fast, workers had to dig deep sunken shafts at both ends of the bridge. Digging down, the engineers found the ground much harder than the survey had said. They had to cut the earth with high-pressure jets of water. One man who was there compared it to digging a well. The earth looks soft, and only when you dig down do you learn how hard it is.

Work on the site began in January 2003. Once the two towers stood firm, the bridge workers built a walkway hanging in the air. It was shaped like a ladder lying on its side and stretched across the mouth of the bay, so that people could move about and work safely. Then the cables were pulled up one strand at a time, drawn taut, adjusted evenly, and gathered into big bundles. The work took more than six years from the first day to the last.

On February 26, 2009, the two ends of the deck were joined in the closing ceremony. Nearly five months later, on July 19 of the same year, the bridge was opened with the prime minister present. On that very day, on the same river, work began on another bridge, the Rồng Bridge. The city was adding new bridges then, and Thuận Phước was the one reaching out closest to the sea.

The river has a whole row of bridges. The Nguyễn Văn Trỗi Bridge, a steel truss, was finished in 1965. Around 2000 came the swing bridge over the Hàn, designed by Vietnamese engineers on their own. Thuận Phước followed in 2009, and the Trần Thị Lý Bridge opened in 2013. Each one is another span joining the two banks.

The deck of Thuận Phước is 18 meters wide, enough for four lanes of traffic and two separate walkways for people on foot. The bridge connects Tiên Sa port with the Hải Vân Tunnel side. It also joins Nguyễn Tất Thành Road to that side. So besides the visitors who come for the view, it is still a real road for the city. Below, ships pass through a gap 27 meters high. At night, the lights are arranged like a bird spreading its wings out toward the open sea, and patches of light keep changing color. Years later, the city banned trucks over 1 ton from crossing, for the sake of order, traffic safety and appearance, since the bridge is one of its highlights.

Back to the first number: 405 meters, about 500 steps. Anyone who has walked along the bridge as evening falls knows that stretch is not long at all. The wind from the bay blows against the cheek. The river glows on one side and the sea opens out on the other. People keep walking, on and on, as if along one enormous string of a musical instrument stretched between two banks.

The lights on the bridge come on, the wings of light brighten toward the sea, and the wind blows across 405 meters without a single pier, plucking that string.