When Emily Roebling walked across the Brooklyn Bridge on May 24th, 1883, the first person to cross its entire span, she capped a family saga equal parts triumph and tragedy, a story that began sixteen years earlier when her father-in-law, German-American engineer John Augustus Roebling, began design work on the bridge. Roebling had already built suspension bridges over the Monongahela River in Pittsburgh, the Niagara River between New York and Canada, and over the Ohio River between Cincinnati and Covington, Kentucky. But the bridge over the East River was to be something else entirely. As Roebling himself said, it “will not only be the greatest bridge in existence, but it will be the greatest engineering work of the continent, and of the age.”
New York City officials may have had little reason to think so in the mid-1860s. “Suspension bridges were collapsing all across Europe,” notes the TED-Ed video above by Alex Gendler. “Their industrial cables frayed during turbulent weather and snapped under the weight of their decks.” But the overcrowding city needed relief. An “East River Bridge Project” had been in the works since 1829 and was seen as more necessary with each passing decade. Despite their misgivings, the authorities were willing to trust Roebling with a hybrid design that combined methods used by both suspension and cable-stayed bridges. Two years later, he was dead, the result of a tetanus infection contracted after he lost several toes in a dock accident.
Roebling’s son Washington, a civil engineer who had fought for the Union Army at the Battle of Gettysburg, took over the project, only to suffer from paralysis after he got the bends while trapped inside a caisson in 1870. For the remainder of the bridge’s construction, he would advise from his bedroom, relaying instructions through his wife Emily—who became after a time the bridge’s de facto chief engineer. She “studied mathematics, the calculations of catenary curves, strengths of materials and the intricacies of cable construction,” writes Emily Nonko at 6sqft. She knew the bridge so well that “many were under the impression she was the real designer.”
“1.5 times longer than any previously built suspension bridge,” the video lesson notes, Roebling’s design worked because it used steel cables instead of hemp, with towers rising over 90 meters (295 feet) above sea level. This is almost three times higher than editors at the New York Mirror projected in 1829, when they called the brand new “East River Bridge Project” an “absurd and ruinous” proposition. “Who would mount over such a structure, when a passage could be effected in a much shorter time, and that, too, without exertion or trouble, in a safe and well-sheltered steamboat?”
Just six days after Emily Roebling crossed the newly opened Brooklyn Bridge, a stampede killed twelve people, and months later, P.T. Barnum led 21 elephants over the bridge to prove its safety. Who would cross such a structure? It turned out, for better or worse, anyone and everyone would drive, walk, run, subway, bike, scoot, climb up, leap from, and otherwise “mount over” the East River by way of the neo-gothic wonder (and later its much uglier sibling, the Manhattan Bridge). Learn much more in the short lesson above how John A. Roebling’s bombastic claims about his design were not far off the mark, and why the Brooklyn Bridge is one of the greatest engineering feats in modern history.