New York is a city of bridges—there are 20 connected to Manhattan island alone. This is the story of the city’s oldest bridge, a story older than the Civil War. It's the story of a bridge most notable not for what was carried on its deck, but for what was carried on the inside. This is the story of the High Bridge.

Recently, I was lucky enough to take a tour of the High Bridge from staff of both the NYC Parks Department and the NYC Department of Design and Construction (DDC).

The High Bridge spans the Harlem River to connect the area around West 170th Street in the Bronx to the area around West 173rd Street in Manhattan. (Why West 173rd Street and not East, since this is eastern Manhattan? Because it is technically west of 5th Avenue.)

The bridge was part of the Old Croton Aqueduct and literally brought New York City its lifeblood: clean water. The aqueduct went into service in 1842, with one pipe crossing the Harlem River somewhere around river level. The bridge was built around it with one 36-inch pipe inside and was completed in 1848. After the initial pipe was removed, a second 36-inch pipe was added to the inside the bridge.

According to Ellen Macnow, High Bridge Project Coordinator for the Parks Department, the origin of the bridge's name goes back to the 1830s, when there was a debate over whether to build a low bridge, a high bridge, or a tunnel. They went with a high bridge and now we have the High Bridge. Inventive!

The original 36-inch pipes were replaced by a single 90-inch pipe in 1861 or 1862, but plugs from the original 36-inch pipes remain inside the bridge. According to Macnow, the water service continued inside the bridge with only two notable interruptions.

The first was in the 1920s when the five stone arches that crossed the river were removed and in 1927, a single steel span replaced them. The reason for their removal was to improve navigability on the Harlem River for both military and commercial purposes. Because other sources of water were already flowing into Manhattan, the entire bridge was nearly demolished. But it was saved, in part, for history's sake.

The second notable interruption occurred during World War II, when officials feared sabotage. "It really tells the story of New York City," Macnow said of the bridge. "It tells the story of the needs of New Yorkers. It tells the story of politics and finance."

One particular story about the High Bridge stands out as both sinister and apocryphal. "The urban legend is that somebody on the bridge threw something off and killed a person on the Circle Line," Macnow said. "The true story, I found in the New York Times, is that there were youths—'hoodlums' in the parlance of the day—in 1952, 1953, 1954, who were throwing things off the bridge and they injured people on the Circle Line and nobody has forgotten that story." Macnow added, "Now we want to give the bridge a new story."

Water continued flowing through the bridge until 1958, and people were able to cross on its deck 116 feet above the Harlem River until about 1970. Since then, it has been off-limits to the public, but the city is in the midst of a $61 million project to rehabilitate the bridge and reopen the deck.

The project is a joint effort between the Parks Department. and the DDC, and is part of Mayor Michael Bloomberg's PlaNYC. Officials hope to open the deck of High Bridge to the public in June of 2014, reconnecting the Highbridge neighborhood with Washington Heights and allowing residents to walk or bike across the historic 1,200-foot-long structure.

"Just the idea of that reconnection has tremendous symbolism, I think, for both communities," says David Burney, Commissioner of the Department of Design and Construction. "It's this piece of industrial archeology, this huge pipe system that was carrying water across and into Manhattan that we're preserving and keeping as a piece of history," Burney says, "We do a lot of bridge reconstruction. But this is very special."

Some are already hailing the High Bridge as another High Line-like project.

"Long linear spaces en vogue in New York City," admitted Jennifer McCardle Hoppa, Administrator for Northern Manhattan Parks for the Parks Department. As part of the project, the bridge deck will be restored and parts of it will be resurfaced. (An interesting thing to note is that the original stone arch portion of the bridge—and one stone arch remains on the Manhattan side—was surfaced in a herringbone pattern, but the steel portion was not.)

The original railings are also being restored for re-installation, but they are very short. So a new 8-foot-tall outer safety fence will be added behind them. But don't worry, you'll be able to focus your camera through them to get pictures about as unobstructed as those you would take from the 86th floor of the Empire State Building.

Macnow said the work being done now is designed so that no significant work will be needed for another 30 to 50 years. While only the bridge deck will be open the public, the city has been doing work restoring and cleaning up the inside of the bridge as well. We asked one of the engineers on the project if anything surprising was found inside. His answer: raccoon skeletons.

Evan Bindelglass is a journalist, blogger, history buff, foodie, and cinephile living just across the Hudson River in Bergen County, N.J. He previously wrote for Gothamist about a private tour of the Washington Arch.

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