Eads Bridge

Stand still for a moment and listen. Beneath your feet, a MetroLink train hums along the lower deck, and the steel answers with a low, steady vibration. Above it all, the wide brown Mississippi slides past, heavy with silt from half a continent. The arches of this bridge look calm and almost delicate from the riverbank. Yet they have carried trains, wagons, cars and people for more than a century and a half.

This is the Eads Bridge, linking Saint Louis, Missouri, with East Saint Louis, Illinois. When it opened in 1874, nothing like it existed anywhere. It was the first major bridge in the world to use steel as its main structural material. At that time, most engineers still trusted iron, wood and stone. Steel was new, expensive and poorly understood. Choosing it was a gamble, and the man who made that gamble was not even a trained engineer.

James Buchanan Eads taught himself. As a young man, he made his fortune on the bottom of this same river. He designed a diving bell and salvaged cargo from sunken steamboats, walking along the riverbed in the dark and cold. He came to know the Mississippi from underneath — its shifting sands, its fierce currents, its hidden depths. During the Civil War, he built ironclad gunboats for the Union navy. So when he proposed a bridge here, he spoke from long and hard experience.

The river itself was the great problem. The Mississippi at Saint Louis is wide and fast, and its bed is made of loose sand that moves with every flood. Ice floes push against anything in their path in winter. Steamboat owners also wanted wide, high openings so their boats could pass. Eads answered with three long arches resting on just two piers in the water. This design kept the channel open and put the foundations where the river could not easily undermine them.

Those foundations hold the first surprise most visitors never hear about. To reach solid bedrock, workers sank enormous pneumatic caissons. A caisson is a giant box with an open bottom, filled with compressed air to keep the water out. Men worked inside it, digging away the sand as the structure sank lower and lower. On the Illinois side, the work went down more than one hundred feet below the river's surface. It was among the deepest such work ever attempted at that time.

The cost of that depth was human. When workers left the high-pressure air too quickly, many fell sick with severe pain, paralysis and sometimes death. Today we call this decompression sickness, or the bends. Back then, doctors barely understood it. More than a dozen men died during the work on these piers, and many more were injured. The bridge physician studied the cases closely, and his observations helped later builders protect their crews. When you look at the stone piers, remember the men inside them.

Now look up at the arches themselves. The central span stretches about 520 feet, and the two side spans are only slightly shorter. When the bridge opened, these were the longest arch spans in the world. Each arch is built from steel tubes, joined in sections and braced together like the ribs of a ship. The steel was made to strict new standards, and Eads insisted on testing it again and again. Many suppliers struggled to meet his demands.

Here is the second surprise. The arches were built without any support from below. Normally, arches rise on temporary wooden frames standing in the water. But a frame in the Mississippi would block boats and fall to the ice and floods. Instead, the builders extended each half-arch outward from the piers, holding it in place with cables from above. The two halves crept toward each other over the open river until they met in the middle. It was a daring method, and it worked.

The opening came in the summer of 1874, with parades, speeches and crowds along the levee. But many people did not trust this strange steel structure. According to a popular story, an elephant was led across the bridge before the opening. People believed elephants would refuse to step onto anything unsafe. Accounts also describe a heavy test with many locomotives standing on the spans at once. The bridge did not move. The public was convinced.

The bridge was built as a double deck, and you can still see that layout today. The upper level carried road traffic, horses and pedestrians. The lower level carried railway trains, which entered Saint Louis through a tunnel under the downtown streets. That tunnel and the lower deck now serve the MetroLink light rail system. So the same structure that once carried steam locomotives still moves thousands of commuters across the river every day.

The bridge has not always had an easy life. Business troubles followed its opening, and later, newer bridges took much of its traffic. For some years in the late twentieth century, the upper deck was closed to cars. Restoration work brought it back into use, and the old steel was cleaned and repaired. The bridge was named a National Historic Landmark, and engineers around the world still study its design. Look closely and you can see rivets and plates from different eras of care.

From the walkway, the view opens in every direction. To one side rises the Gateway Arch, the stainless steel monument to westward expansion. To the other, the river bends away toward Illinois, its barges moving slowly against the current. Just behind you lies Laclede's Landing, a small district of old brick warehouses and cobbled streets. Together they show two very different kinds of arch, built nearly a century apart, each one a statement about this river city.

Before you leave, rest your hand on the railing and feel the faint tremor of the next train passing below. Watch how the light falls across the steel ribs and the grey stone piers. Somewhere under that brown water, the foundations still sit on bedrock, where men once dug by lamplight in compressed air. As you walk back toward the city, glance over your shoulder. The three arches will still be there — quiet, steady, and doing exactly what Eads promised they would.