The severe winter of 1866 was the catalyst for construction of Brooklyn Bridge across the Hudson River between Manhattan and Brooklyn. Temperatures were so cold that the river froze, paralysing ferries and fuelling calls for a fixed link.
The project was the brainchild of an arrogant but forceful Prussian born engineer, John Roebling, who conceived the 480m central span bridge as a landmark gateway to the New World.
Roebling's design pioneered the use of steel cables to support the bridge's main span. Iron was generally preferred to steel in the mid 19th century because steel was relatively untried. But Roebling considered iron to be too weak to support such a long span.
Unfortunately Roebling died before construction began. During a site investigation trip on the Hudson a ferry crushed his right foot as it docked. Ignoring medical advice, he treated himself, eventually deciding to have his toes amputated without anaesthetic. He died three months later.
Roebling's 32 year old son Washington then took on the project, acting as chief engineer during the construction phase which started in 1870. A former army colonel, Roebling junior was a hands on manager who insisted on getting close to the action on site. He even got the bends twice while supervising excavations in compressed air under the huge timber caisson for the tower at the New York end.
Sinking the New York caisson down to the bed rock was one of the trickiest parts of the whole project. Little was understood about the need for gradual decompression after work in compressed air, and several workers died of the bends as a result.
Washington Roebling survived, but the mounting number of bends cases persuaded him to gamble on abandoning the caisson before it reached the bed rock.
Construction of the Brooklyn tower was easier as the bedrock was only 12m below the river bed. As a result the tower was completed by July 1875, just over a year ahead of its New York twin.
Things never appeared to run smoothly for Roebling. Steel wire manufacturers successfully overturned his decision to award the contract for the cables to the family steel mill. Unfortunately the chosen contractor skimped and produced lower grade wire than specified. Roebling then had to order the manufacturer to add another 150 wires to each cable at its own expense.
The bridge finally opened in 1883 and the fact that it still stands today is a testament to the Roeblings' thoroughness and determination.