Victoria Falls Bridge

Listen first. Under your feet, the steel deck carries a low, steady hum. Far below, the Zambezi River throws itself against black rock, and the sound rises up the gorge like distant traffic that never stops. Fine spray drifts across the railings and settles on your skin. On some days it falls as light rain under a clear blue sky. You are standing on the Victoria Falls Bridge, high above the Second Gorge, with one country behind you and another ahead.

This is a border as well as a bridge. On one side lies Zimbabwe and the town of Victoria Falls. On the other lies Zambia and the town of Livingstone. The middle of the span sits in a kind of no-man's-land between two immigration posts. People cross on foot, by car, and by train. Traders push loaded bicycles across. Tourists stop to stare over the edge. Everyone shares the same narrow strip of steel above the water.

The falls themselves are close by, just upstream. Local people have long called them Mosi-oa-Tunya, which means "the smoke that thunders." On a good day you can see why. A white column of mist rises above the trees, sometimes visible from many kilometres away. The Scottish missionary David Livingstone reached the falls in 1855. He named them after Queen Victoria. The local name never disappeared, though. Today you will hear both names, often in the same sentence.

The idea for this bridge came from Cecil Rhodes, the British businessman and colonial politician. Rhodes dreamed of a railway running the length of Africa, from the Cape to Cairo. The Zambezi gorge was a major obstacle on that route. Rhodes reportedly wanted the bridge placed close enough to the falls that passing trains would catch the spray. Whether he said it in exactly those words is hard to prove. But the bridge was built here, and the spray does reach it.

Rhodes never saw the result. He died in 1902, before construction finished. The design came from the engineer George Andrew Hobson, working for the London consulting firm of Sir Douglas Fox. The steelwork was made in northern England, by the Cleveland Bridge and Engineering Company of Darlington. Every piece had to travel by ship to Africa, then inland by rail. Then it had to be assembled over a gorge with no ground to stand on.

That was the central problem. You cannot build scaffolding up from a river this violent and this deep. So the engineers built outward from both cliffs at once. Each half of the arch reached out over the void, held back by heavy cables anchored into the rock behind. Slowly, the two halves crept toward each other. A cableway strung across the gorge carried workers and materials over the drop. It must have been terrifying work.

There is a story about the moment the halves met. It is told so often that it is now part of the bridge's character. According to the popular account, the two sections did not line up at first. The African sun had heated the steel, and the metal had expanded. The workers waited. In the cooler hours, the steel shrank back, and the pieces finally joined. Treat the details as a good tale, but the physics behind it is real. Steel moves with temperature.

The bridge opened in 1905. The formal opening was performed by George Darwin, a mathematician and astronomer, and the son of the naturalist Charles Darwin. He was in southern Africa with a visiting party of British scientists. So a son of the man behind the theory of evolution cut the ribbon on a railway bridge over the Zambezi. It is one of those small historical connections that most visitors walk past without knowing.

Now look at the shape of the structure. The main element is a single steel arch, rising from the rock on either side and carrying the deck above it. The steel is laced with diagonal bracing, a dense pattern of triangles. Triangles are rigid. They do not bend out of shape under load. That is why the lattice looks so busy. Every crossing bar has a job. Notice the rivets too. Thousands of round heads stud the steel, each one hammered in by hand.

The bridge also carries a surprising piece of political history. In 1975, a train stopped in the middle of this span. Inside a railway carriage, leaders of white-ruled Rhodesia met Black nationalist leaders for talks about the future of the country. The neutral ground was exactly the middle of the bridge. The talks failed. Years of war followed before Zimbabwe became independent in 1980. But for one day, this strip of steel was the only place both sides would meet.

Today the bridge has a newer reputation. People jump off it. A bungee platform sits near the middle of the span, and the drop toward the river is enormous. You may hear a scream echo off the gorge walls while you stand here. Other visitors swing across the gorge or take guided walks along the underside of the deck, among the old steel beams. Whatever you choose, it is worth watching for a few minutes. The reactions of the crowd are half the show.

Look down into the gorge, if you have the nerve. The rock is dark basalt, an ancient volcanic stone. The river has cut through it along lines of weakness, carving a zigzag of gorges. The falls have moved upstream over a very long time, leaving each old gorge behind like a footprint. The water below you is fast and churning. Just upstream sits a deep pool where the current swirls, known as the Boiling Pot. In the right light, a rainbow hangs in the spray.

Before you leave, stand still for a moment. Feel the deck shift very slightly as a truck rolls past. Listen to the thunder upstream and the birds calling along the cliffs. Watch the mist rise and drift over the trees. More than a century ago, people hung over this drop on cables and bolted this arch together piece by piece. Now it simply carries you across. As you walk off the bridge, look back once. Notice how small it looks against the gorge.