There’s a 18 mile long "Hidden" Wire Above Manhattan That You’ve Probably Never Noticed Called an Eruv
It's hard to imagine that anything literally hanging from utility poles across Manhattan could be considered "hidden," but throughout the borough, about 18 miles of translucent wire stretches around the skyline, and most people have likely never noticed. It's called an eruv (plural eruvin), and its existence is thanks to the Jewish Sabbath.
Every Thursday and Friday morning, Rabbi Moshe Tauber leaves his home in Rockland County, New York, at about 3:30 a.m. He arrives in Manhattan an hour later and drives the 20-mile length of a nearly invisible series of wires that surrounds most of the borough. He starts at 126th Street in Harlem and drives down, hugging the Hudson River most of the way, to Battery Park and back up along the East River, marking in a small notebook where he notices breaks in the line. Known as an eruv, the wire is a symbolic boundary that allows observant Jews to carry out a range of ordinary activities otherwise forbidden on the Shabbat.
On the Sabbath, which is viewed as a day of rest, observant Jewish people aren't allowed to carry anything—books, groceries, even children—in public places (doing so is considered "work"). The eruv encircles much of Manhattan, acting as a symbolic boundary that turns the very public streets of the city into a private space, much like one's own home. This allows people to freely communicate and socialize on the Sabbath—and carry whatever they please—without having to worry about breaking Jewish law.
Along with everything else in New York City, the eruv isn't cheap. It costs a group of Orthodox synagogues $100,000 a year to maintain the wires, which are inspected by a rabbi every Thursday before dawn to confirm they are all still attached. While wires do occasionally fall, the overall eruv has survived events such as the Macy's Thanksgiving Day Parade and Hurricane Sandy. When eruv wires do break, it can cause enough of a stir to make news. Most notably, in 2011 a wire broke near the United Nations building, which caused a problem when repair crews couldn't get past security to fix it. The issue was eventually resolved, but not before a good deal of panic set in.
Manhattan has had an eruv in one form or another since the early 20th century, but the present-day incarnation began on the Upper West Side in 1994. It has since expanded from 126th Street to Houston Street, and its exact locations can now be viewed on Google Maps (and an intermittently updated Twitter feed). The city does have some rules in place regarding the eruv: The wires can only be a quarter-inch thick, and they must be hung at least 15 feet off the ground.
New York City isn't the only metropolis in the U.S. with an eruv. They can also be seen (or not seen) in St. Louis, Atlanta, Baltimore, Chicago, Dallas, and numerous other cities across the country.
But a single break in any part of the line voids that symbolic space. According to the 100 pages devoted to eruvin in the ancient Talmud, the boundary is only effective when the entire line is intact. And there are plenty of ways these breaks can happen. Sometimes it’s the elements, but more often construction is responsible.
Recent breaks have been attributed to public protests in the city.