Throwback Thursday: Water Under the Bridge, Danger Under the Water

This blog post was written by Dan Antonellis in honor of Brooklyn Bridge Opening Day, which was Wednesday! After 14 years of construction, the Brooklyn Bridge opened to traffic on May 24, 1883, connecting Manhattan and Brooklyn for the first time in history. Dubbed the “eighth wonder of the world,” the bridge changed New York City forever.

Fill a bathtub with water and find a drinking glass. Flip the glass upside down and push it to the bottom of the tub. The water from the tub won’t get inside the glass because of the air trapped inside. It’s about air pressure, physics and other science-related topics I won’t even attempt to explain in this post.

Now stay with me. Picture tiny people standing inside that glass on the bottom of the tub, chipping away at the porcelain with miniature picks and shovels. The air in that glass will eventually run out, so you’ll need a tube poking out of the top of the glass and up and out of the water so that good air can come in and bad air can get out. After all, these tiny people need to breathe as they continue picking away and digging at the bottom of your tub.

Holding a glass upside down at the bottom of the bathtub is the basic premise behind one of the most intriguing and dangerous feats in U.S. engineering and construction history — the building of the underwater foundations that would lie at the bottom of New York’s East River and support the massive towers of the historic Brooklyn Bridge.

The Great Bridge

The vision for “The Great Bridge” (later named the Brooklyn Bridge) was simple enough — to connect Manhattan and Brooklyn and open travel and trade between the two independent cities. (Brooklyn was its own city until it was annexed by New York City in 1898.) The bridge would eventually span 1,600 feet across the river, connecting two masses of land that had been separated by water for millions of years.

BrooklynBridgeSchematic

An early plan for the Brooklyn Bridge. (Courtesy of the National Archives and Records Administration)

The Brooklyn Bridge was designed like most suspension bridges. While they differ aesthetically and hold distinct places in history, they all share certain visual and engineering characteristics in common. Cables that stretch from bridge towers to the highways like giant spider webs. Roads seemingly suspended in air — many of which can span from 2,000 to 7,000 feet long. And of course, the massive towers that stand tall and strong, anchoring the bridge components to the earth and literally holding it all together. Those towers need to be firmly grounded and dug into bedrock, like any other tall structure.

Back in 1869, long before the days of pounding piles into the ground using sophisticated equipment and heavy machinery, there were men, picks and shovels. And plenty of danger to go around. Continue Reading ›