Prince of Wales Bridge

Stand on the Welsh shore and listen first. There is a low, steady hum, rising and falling with the traffic, carried across the water on the wind. Beneath it you hear the estuary itself: the suck and slap of brown water over mud, the cry of wading birds, and the tide moving faster than you expect. Then lift your eyes. A long, pale line of concrete runs out across the Severn, low to the water, until it rises into two tall towers strung with cables.

This is the Prince of Wales Bridge. For most of its life it had a plainer name: the Second Severn Crossing. It opened in 1996 and carries the M4 motorway between England and Wales. It was given its current name in 2018, in honour of Prince Charles, who was then the Prince of Wales. The renaming was not universally popular. Many people in Wales objected, and a petition against it gathered wide support. You will still hear plenty of locals call it simply the second crossing.

A quick word on geography, because it surprises many visitors. Chepstow sits at the mouth of the River Wye, a few miles to the north. The bridge you can see from Chepstow most easily is actually the older Severn Bridge, opened in the 1960s. The Prince of Wales Bridge lies further downstream, to the southwest, between Severn Beach on the English side and the area around Sudbrook and Rogiet on the Welsh side. Both bridges belong to the same story.

That story begins with the river. The Severn Estuary has one of the largest tidal ranges in the world. Twice a day the water rises and falls by a height greater than a tall house. At low tide, vast banks of mud and rock appear. At high tide, they vanish under fast, cold water. For centuries this made crossing dangerous. Ferries ran here, but they worked only with the tide, and the currents demanded skilled crews.

By the 1980s, the older Severn Bridge was carrying far more traffic than its designers had planned for. Queues built up. Wind sometimes forced restrictions on the high, exposed deck. A second crossing was the answer. It was built by a private consortium, and the cost was recovered through tolls paid by drivers entering Wales. Those tolls lasted more than twenty years. They were finally abolished at the end of 2018, and many local businesses and commuters celebrated the change.

Now look at the shape of the structure. Most of its length is not the dramatic part. It is a long series of approach viaducts, resting on concrete piers that march across the mudflats. Altogether, the crossing runs for about five kilometres. Many sections were made on land and then lifted into place, because working out on the estuary was difficult. Engineers had to plan around the tides. Some tasks could only happen in the short windows when the water was low.

In the middle, the bridge changes character. Here the two towers rise, and fans of steel cables run down from them to hold the deck. This is called a cable-stayed design. The cables connect directly from the towers to the road, rather than hanging from one great curved cable like the older bridge upstream. This central section crosses a deep-water channel known as The Shoots. It is the main route for ships moving up the estuary, so the deck needed to rise high here.

Here is a detail most drivers never notice. Along the edges of the deck there are wind screens. The Severn is an exposed place, and strong gusts blow straight up the estuary from the sea. The screens help protect vehicles from sideways wind. This was one of the lessons learned from the older bridge, which had to close to some traffic in bad weather. The newer crossing was designed to stay open in conditions that would trouble its neighbour.

And here is a second surprise. Beneath your feet, or very close to them, runs one of the great works of Victorian engineering. The Severn Tunnel carries the main railway line under the estuary. It was completed in the late nineteenth century, after years of struggle with flooding underground springs. Trains still use it today. So at this point you have road above the water and rail below the riverbed. Two centuries of engineering share the same stretch of estuary.

The rocks near the bridge have a story too. Out in the river lies a reef called the English Stones. At low tide it shows as a wide shelf of dark rock. The bridge piers use some of this firmer ground. The old ferry crossings once worked around these same rocks. Further along the shore, at Black Rock near Portskewett, local fishermen have long used a traditional method called lave net fishing. They wade into the shallows with large wooden-framed nets to catch salmon.

If you come to the shore, take a moment to watch the water itself. The colour is not clear blue. It is a milky brown, full of fine silt carried by the tides. This silt is part of why the mud banks are so wide. It also makes the estuary dangerous to walk on. The mud can be soft and deep, and the incoming tide moves quickly across flat ground. The coastal paths are the safe place to be.

The light here changes the bridge through the day. In the morning, the low sun from the east can turn the concrete pale gold. On grey days the towers fade into the mist, and the cables become thin pencil lines. At dusk, the lights along the deck come on, and the line of the crossing glows above the dark water. Photographers often prefer the Welsh shore near Sudbrook or Black Rock for a long side view.

Think, too, about what the bridge means to the people who use it. For some, it is a daily commute between Newport, Cardiff and Bristol. For others, it is the moment they know they are home. Many travellers notice the change of signs as they cross, with Welsh appearing alongside English. The name on the bridge may be debated, but the crossing itself is part of ordinary life on both sides of the river.

So before you leave, look again at that long line over the water. Listen for the hum of tyres, and for the birds out on the mud. Watch the tide for a few minutes, and you may see it move. Upstream, the older bridge stands near Chepstow. Below the river, trains run through the Victorian tunnel. And here, in between, the newer crossing carries on with its quiet work, connecting two countries across a restless estuary.