The Brooklyn Bridge

Originally called the "New York and Brooklyn Bridge" or the "East River Bridge" prior to gaining its current name in 1915, the Brooklyn Bridge is one of the engineering marvels of the 19th century.  Completed in 1883, the bridge was initially designed by engineer John Augustus Roebling (1806–1869) and completed under the auspices of his son, Washington Augustus Roebling (1837–1926), and his daughter-in-law, Emily Warren Roebling (1843 – 1903).  Their creation linked the cities of Brooklyn and New York via what was then the world's longest suspension bridge just a few years before the counties surrounding Manhattan Island were combined to form today's New York City.

Despite the brilliance of the Roeblings, the usually reliable and predictable geography of New York played havoc with the placement of the bridge's Manhattan tower.  Huge work areas called "caissons" were sunk into the East River, pressurized, then workers entered the caissons to dig into the riverbed in search of bedrock.  The effort on the Brooklyn side proceeded as the Roeblings expected, but on the Manhattan side bedrock was never hit.  After digging about 80 feet down and watching worker after worker fall from "Caisson Disease" (today called "the bends"), the Roeblings ordered the Manhattan caisson to be filled with concrete, thus creating the base for the tower on the Manhattan side.  The same process was done on the Brooklyn side, but with the difference that bedrock was hit and dug into for that tower.

The end result?  The Brooklyn side of the bridge is standing on concrete and anchored in bedrock.  Conversely, the Manhattan side—the one where the tower is placed in the waters of the East River—is standing on concrete and held down by its own 90,000-ton weight and the sand piled around it. Keep that in mind when reading the following:

To this day,
no protective barrier exists
around the exposed and unsecured
Manhattan support
of the Brooklyn Bridge.

-TechRider