How the Brooklyn Bridge was built, step by step: the caissons, the bends, the Roeblings and fourteen years over the East River

Architecture · 4 September 2026

The Brooklyn Bridge was built between January 1870 and May 1883 across the East River between Brooklyn and Manhattan, to the design of John A. Roebling, who died of tetanus before the work began, and under his son Washington Roebling, who was crippled by caisson disease in 1872 and directed the remaining eleven years from his bed, with his wife Emily carrying his instructions to the site and learning enough engineering to answer for him. Its 1,595-foot main span was the longest in the world, half as long again as any before it, and its towers were the tallest structures in New York; it was the first bridge to use steel-wire cables, the first to use pneumatic caissons at such depth in America, and it cost 15 million dollars and about 27 lives. Below: each stage of the construction, from the caissons to the cables and the deck, the people, the opening, the numbers and the stories, with the age it belongs to in Victorian architecture and its engineering cousins in how the Eiffel Tower was built.

The plan and the Roeblings

John Augustus Roebling, born in Prussia in 1806, emigrated in 1831, founded a wire-rope factory in Trenton, New Jersey, and built the suspension bridges at Niagara (1855), the first to carry a railway, and Cincinnati (1866), then the longest in the world; in 1867 he was appointed chief engineer of the New York Bridge Company, chartered to bridge the East River, whose ferries carried 40 million people a year and froze in winter. His design of 1867 was a suspension bridge with a main span of 1,595 feet and two side spans of 930, hung from four cables over two Gothic-arched granite towers 276 feet high, with a system of diagonal stays from the towers that would hold the deck even if the cables failed, "a work which will be the greatest bridge in existence, and a great work of art", six times stronger than it needed to be. In June 1869, while surveying the Brooklyn tower site, his foot was crushed by a ferry against the pilings; he refused conventional treatment, and died of tetanus on 22 July. His son Washington, 32, a Civil War colonel who had studied caissons in Europe, was made chief engineer. Brooklyn Bridge.

Step 1: the caissons, 1870–1872

The towers had to stand on bedrock or hard ground under the river, and the way to get there was the pneumatic caisson: a huge box of timber, open at the bottom, sunk on the riverbed, with compressed air pumped in to keep the water out so that men could dig inside it while masonry was piled on top, the box sinking as the ground was removed. The Brooklyn caisson, 168 by 102 feet with a roof of timber 15 feet thick, was launched in March 1870 and towed into place; inside, in a chamber 9 feet high lit by calcium lamps, 100 men at a time worked in shifts, digging boulders out of the glacial till, breaking them with small explosive charges, and sending the spoil up through water-filled shafts, while the air pressure rose as they went down. It reached hard ground at 44 feet in March 1871, was filled with concrete, and the tower rose on it. The Manhattan caisson, launched in May 1871, had to go deeper, and the pressure at 70 feet was above 30 pounds per square inch; at 78 feet, with bedrock still uneven below and the men dying, Roebling stopped and founded the tower on the packed sand, which has held for 140 years. A fire in the Brooklyn caisson's timber in December 1870 burned inside the roof for days before the chamber was flooded to put it out.

The bends

The men who came up too fast from the compressed air suffered what they called "caisson disease" and later "the bends", the nitrogen dissolved in their blood forming bubbles as the pressure dropped: pains in the joints, paralysis, and death. Nobody yet understood it; the company's doctor, Andrew Smith, recorded 110 cases in the Manhattan caisson and three deaths, and recommended slower decompression, which was not adopted, decompression taking a few minutes rather than the hour or more it needed. Washington Roebling spent more time in the caissons than anyone, and in the spring of 1872 collapsed after coming up; he was partly paralysed, in pain, sensitive to light and sound, and never again went on the site. From 1872 to 1883 he ran the bridge from his house on Columbia Heights in Brooklyn, watching the towers and cables through a telescope from his window and dictating every instruction to his wife. Emily Warren Roebling, who had studied mathematics and had taught herself cable construction, stress analysis and catenary curves, went to the site daily, dealt with the contractors, the engineers and the trustees, and became, in effect, the resident engineer; the trustees tried to remove Washington in 1882 and she argued them out of it. She was the first person to cross the finished bridge, in a carriage with a rooster on her lap.

Step 2: the towers and the anchorages, 1872–1876

The towers are of granite from Maine, 276 feet 6 inches above the water, each with two pointed Gothic arches 117 feet high through which the roadway passes, built with derricks on the tower tops that lifted the blocks from barges; the Brooklyn tower was finished in 1875 and the Manhattan tower in 1876. At each end of the bridge an anchorage, a masonry block of 60,000 tons, was built on land, with four cast-iron anchor plates buried at its base and chains of iron eyebars curving up through the stone to the top, where the cables would be fastened; the anchorages are the parts most people never notice, and the bridge hangs from them. In August 1876 the first wire rope was carried across the river by boat and hoisted to the tower tops, and the master mechanic E.F. Farrington rode across on it in a boatswain's chair in front of a crowd of thousands, to show it was safe.

Step 3: spinning the cables, 1877–1878

The four main cables, each 15.75 inches thick, were not lifted into place but made in the air. A travelling wheel ran on an endless rope from anchorage to anchorage, carrying a loop of steel wire across the river and back; each trip laid two wires, and 278 wires made a strand, and 19 strands, bound and wrapped with more wire, made a cable, 5,434 wires and 3,515 miles of wire in each, 14,357 miles in all. The wire was galvanised steel, the first use of steel in a bridge cable, made in Trenton and elsewhere; the contract went to J. Lloyd Haigh of Brooklyn, a friend of a trustee, over Roebling's objection, and in 1878 it was found that Haigh had been passing rejected wire through the inspection by switching wagons, so that the cables already contained wire that would have failed the test. Roebling calculated that the bridge was still four times as strong as it needed to be, added 150 extra wires to each cable, and left the bad wire in; it is there today. Spinning took from June 1877 to October 1878; the cables were then wrapped, and 1,520 suspender ropes hung from them to carry the deck, with 400 diagonal stays from the towers.

Step 4: the deck and the opening, 1879–1883

The deck was a steel-truss floor 85 feet wide, with two roadways for carriages, two tracks for cable-hauled trains in the middle, and above them the elevated promenade for pedestrians that Roebling had insisted on, "for the benefit of the people"; it was built outward from each tower and from the anchorages, the sections balancing one another. In 1883 the trusses were finished and the bridge was tested with loaded wagons; the official opening was on 24 May 1883, with President Chester Arthur and Governor Grover Cleveland walking across from Manhattan to Brooklyn, fireworks, and 150,000 people crossing on the first day at a cent each. Washington Roebling watched from his window and received the President at home. On 30 May, Memorial Day, a rumour that the bridge was collapsing started a stampede on the promenade stairs and twelve people were crushed to death; a year later P.T. Barnum led 21 elephants, including Jumbo, across it to show it was safe, and to advertise the circus. The trains ran from September 1883 and stopped in 1944; the bridge carries six lanes of cars, a bike path and the promenade today, at about 120,000 vehicles and 30,000 pedestrians a day.

The numbers

• Span. 1,595.5 feet (486 m) between the towers, the longest in the world until 1903; total length 5,989 feet (1,825 m) with approaches.
• Towers. 276.5 feet (84 m) above high water; the Brooklyn caisson at 44.5 feet, the Manhattan at 78.5 feet below.
• Cables. Four, 15.75 inches (40 cm) thick, 5,434 wires each; 14,357 miles (23,100 km) of wire; 3,578 feet long each.
• Clearance. 135 feet (41 m) above the river at mid-span, set by the Navy for sailing ships.
• Time. 14 years, from the start of the Brooklyn caisson in January 1870 to May 1883.
• Cost. About 15.5 million dollars, twice the estimate; around 400 million today.
• Deaths. Officially 20, probably 27, from falls, the caissons and the bends; John Roebling first.
• Strength. Designed for six times its load; still carries traffic on the original cables after 140 years.

Versions and theories

• Emily Roebling designed the bridge. Not the design, which was John's and Washington's; but for eleven years she was the channel between the paralysed chief engineer and the site, learned the engineering, and answered for it. The plaque on the bridge names her with them.
• Roebling watched through a telescope. True, from the back window of 110 Columbia Heights; the house is gone, the view is there.
• The bad wire is still in the cables. True: Roebling left Haigh's rejected wire in and compensated with extra wire; inspections since have found the cables sound.
• "Selling the Brooklyn Bridge." George C. Parker and other con men sold the bridge to immigrants several times around 1900, with deeds and toll booths; the police stopped more than one new "owner" setting up a barrier. Hence the phrase.
• Barnum's elephants proved it safe. They proved that Barnum knew publicity; the bridge had been tested with wagons and a year of traffic. The elephants crossed on 17 May 1884.
• The caisson fire nearly ended the bridge. The fire of December 1870 burned into the Brooklyn caisson's timber roof for a day before it was flooded; had the roof failed, the chamber would have collapsed under the tower's weight. Roebling stayed down for hours directing the fight and took his first dose of the bends there.

The iron and steel age that produced the bridge, its towers and its rivals is in the first skyscraper and how the Eiffel Tower was built.

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