Free
Between 1810 and 1850, the population of Brooklyn, New York, jumped from about 3,000 to over 100,000.
People in Brooklyn had to take a ferry across the East River to get to the island of Manhattan. But the river often froze during the winter, and ferries were overcrowded at rush hour. A new way of crossing was needed. In 1867, former Brooklyn Mayor Henry Cruse Murphy suggested building a bridge. Two years later, construction began. It would become one of the most amazing engineering feats in history.
Explore the Brooklyn Bridge
◀ John Augustus Roebling was the main engineer and designer of the Brooklyn Bridge, but he never got to see it. Before construction even began, he died from tetanus after a freak ferry accident in 1869.
Roebling’s son, Washington, took over the job and worked on it for three years. Then he developed caisson disease (the bends), which kept him from getting out of bed for the rest of his life. Unwilling to give up the job, Washington watched the bridge’s progress through binoculars from his Brooklyn house. His wife took his instructions to the workers. ▶
▲ Building the bridge was dangerous. Inside the wood-and-iron caissons (large, watertight chambers lowered to the riverbed in order to dig foundations), temperatures could be over 80°F. As the workers went deeper, the air pressure increased, which made breathing difficult.
Check It Out!
Some caisson workers got the bends. What are the bends?
The bends are a disorder caused by a quick change in air pressure from rising to the surface too quickly. It’s called that because some people who suffered from them were in such pain they could hardly stand up.
12 Steps to Building the Brooklyn Bridge
▲ 1870: Land for the tower on the Brooklyn side is cleared, and construction begins.
▲ A caisson is lowered to the riverbed on each side. Steam engines pump air into the chambers to force out the water. Workers enter through an air lock to maintain air pressure. They clear away earth and silt from the river’s floor. The plan is to reach the bedrock that will become the foundation for the two piers. Both caissons are filled with concrete and become part of the bridge’s foundation.
▲ 1876: The bridge’s towers, built up from the caissons, are completed.
_340.jpg)
▲ Construction begins on the bridge’s two anchorages. These are located on land and will hold the bridge’s cables in place.
▲ A “traveler rope” is stretched between the two towers to make it possible to cross the East River. The trip takes about 20 minutes.
▲ A temporary footbridge of wood and rope is strung between the bridge’s two towers. It allows workers to go from one side of the river to the other.
▲ Many steel wires are stretched across the span. They are thinner than pencils. They are then twisted together to form two pairs of thicker, stronger cables.
▲ Steel suspenders are hung from the cables to hold the steel deck. Each of these steel suspenders is two inches wide.
▲ Large steel beams are positioned on the bridge’s deck.
▲ The temporary wood and rope footbridge is removed. A sturdy deck is left.
_340.jpg)
▲ Diagonal stay cables that stretch from the towers to the deck are added to the bridge. These cables strengthen and stiffen the deck.
▲ May 24, 1883: The opening ceremonies for the Brooklyn Bridge take place.
