Railroad Transfer Bridge

At the northeast edge of the Brooklyn Navy Yard, at the edge of Wallabout Basin, stands this hulking, rusting ruin, Structure 713. It's a railroad transfer bridge, or float bridge.

These structures were used for transporting freight trains across rivers. There would be a floating pontoon bridge - secured to land on one end, and floating on the other - with train tracks on it. A barge carrying freight cars would be ferried across the water where they could be lifted or roll directly onto the tracks. This system was developed in the mid 1800s in Maryland and Pennsylvania, and soon spread to other cities along the Eastern Seaboard.

It may seem labor-intensive to load a railroad car onto a barge and then back onto land, but consider that in New York, a freight train in Hoboken, NJ would have to travel north along the Hudson River nearly to Albany to cross a bridge to the east side to get to New York City. It could take anywhere from 12 to 36 hours to make a journey that modern commuter trains make in 20 minutes. This route was known as "The Selkirk Hurdle," Selkirk being the location of the nearest Hudson River rail crossing, some 130 miles north of NYC. Float bridges significantly reduced this time, being especially useful for transporting perishable products like fruit and vegetables.

The Williamsburg Bridge in the background

The Navy Yard Transfer Bridge was built in 1941. After the Navy Yard was demilitarized, a private company called Seatrain Lines took over use of the bridge and operated it from 1969 until it went out of business in 1983. It was last used in 1995 by a subway car rebuilder.

The pontoons holding the railroad tracks have long sunk and the whole structure is in decay. Float bridges are not in common use any more, though there is one still operating near the Brooklyn Army Terminal in Sunset Park. Another one very similar to the Navy Yard bridge sits on the Hudson River at 69th St., protected by Landmark Status but similarly rusting away. And there is one in Long Island City, also inactive but preserved and refurbished at Gantry State Park.

One of the things I've discovered since starting to write and research for this blog is that no matter how particular or obscure the subject matter, there is almost always someone out there who has done obsessively detailed research on the subject and built a website or message board devoted to it. The Trainweb site has an extensive history of the BNY rail system here, a list of all NYC-area float bridges here, and a glossary of terms that explains all the technical elements of these systems here.