Welcome to our new feature, Curbed's Could Have Been, where we investigate some of the most outlandish proposals that were never built. Know of a plan that never saw the light of day? Send it to the tipline.

Engineer Gustav Lindenthal, creator of NYC's Hell Gate Bridge and many more throughout the nation, had big plans for the Hudson River. And by "big," we mean a mammoth structure that would have been one of the longest bridges in the world at the time. In the late 1880s, the Pennsylvania Railroad wanted to build a bridge into lower Manhattan, and the company approached Lindenthal. He proposed a giant suspension bridge with a central span of 3,000-feet?nearly twice that of the Brooklyn Bridge, which was complete just a couple years prior. Two 530-foot-tall steel-and-masonry towers would anchor the structure, with side spans of 1,500-feet reaching to Hoboken, New Jersey and near West 23rd Street in Manhattan. Six train tracks would cross the bridge, sitting some 145 feet the river, and it would cost $23 million. By 1890, congress had approved the plan, and the cornerstone was laid in Hoboken on June 18, 1895.

But, like it goes with massive projects, it couldn't be funded, and the Hudson River Bridge never came to be. Lindenthal moved onto other projects, like changing the design for the Manhattan Bridge and working on the Blackwell Island Bridge (now the Queensboro Bridge). All these bridges were fine and dandy, but Lindenthal's dream?his dream!?was to build the Hudson River Bridge. So in the 1920s, as suspension bridges were popping up all over the place, Lindenthal revived his plans.

Despite costs causing the bridge to fail the last time, Lindenthal revamped his designs, calling for a structure so large it would have dwarfed Manhattan (see the lead photo). Go big or go home, right?

This time, the bridge would connect 57th Street to West New York in New Jersey. The center would span 3,240 feet, flanked by side spans of 1,590 feet, and two 825-foot-tall towers were to be constructed on either shoreline. Had they been built, they would have been the tallest structure in the world at the time. The double-decker bridge would carry a whopping 16 lanes of traffic, 12 train tracks, four trolley tracks, and two pedestrian walkways. Whew! It would also sit 200 feet above the water to allow for naval ships to pass underneath. It would cost $100,000,000 (the cost of a Manhattan penthouse today! Oh how times have changed). But because of the high price, he didn't get the necessary approvals and government support, and the bridge was never built. Lindenthal died in 1935, never having realized his dream, which would have made the Woolworth Building look like a puny little thing:

· Gustav Lindenthal [Structure Magazine]

· Hudson River Bridge [NYC Roads]

· The New York City That Never Was: Part II, Bridges [Untapped NY]

· Curbed's Could Have Been archives [Curbed]