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Why does one of America’s most famous bridges have a giant bend in it?

Learn how San Diego's famed Coronado Bridge ended up with its completely unique bend...

Spend some time in and around San Diego and you’re sure to notice the San Diego-Coronado Bridge, the elegantly curved bridge spanning the San Diego Bay to neighboring Coronado. It's one of the most stunning bridges in the entire country. But how did the Coronado bridge end up with such a dramatic design? The answer is pretty darn practical...

How the Coronado Bridge began

As the automobile changed society, the desire for more direct routes via bridges blossomed. San Diego was no different. In the 1920s, San Diego residents put the “wheels in motion” by discussing a bay bridge that could connect Coronado and San Diego. Unfortunately, the U.S. military put the brakes on the bridge for nearly 30 years.

Butting heads with the Navy

While residents may have been calling for a bridge, the Navy was so incensed by the idea they threaten to leave town in the 1930s if the bridge was built. Why? Well, it’s southern California. What if there’s an earthquake? A collapsed bridge could have trapped the entire naval fleet inside the San Diego Bay.

Understanding these concerns, the bridge was nixed by voters until the 1950s. By this time, America had fully gone head-over-heels for the automobile and talks of a bridge began again. The city council commissioned a feasibility study and even the Navy came onboard by the 1960s if one condition was met: the bridge needed a vertical clearance of 200 ft.

This height would allow empty aircraft carriers of the day to still pass beneath the bridge.

Sounds simple enough, right?

Except to get that clearance height the bridge would need to be so steep it would be more like a roller coaster than safe bridge. What’s an architect to do?

An elegant solution

Robert Mosher, the bridge’s architect, decided to simply put a “curve” in the bridge. What was done mostly for necessity became one of the most iconic features of the Coronado Bridge.

By adding the curve, Mosher is able to extend the length of the bridge enough to lower the grade necessary to accommodate the height requirements.

Design and construction

The curve wasn’t the only part of his design that was innovative and beautiful. Resembling a backbone, Mosher implemented a relatively new technique known as “orthopedic roadways” which doesn’t require any overhead supports like you’d see on a suspension bridge. Instead, the bridge has a tubelike design with the world’s longest continuous box girder to disguise the joints of the bridge.

The 30 arched towers of the bridge were supposedly modeled after Cabrillo Bridge in Balboa Park are are said to be design nods to southern California’s many Spanish missions.

Finally, the bridge is painted blue to blend seamlessly with the sky and sea. (Painting a bridge does create some maintenance costs… a full-time crew of 6 is needed year-round to keep painting the thing.)

With Mosher’s design in place, construction began in 1967, and the bridge opened in 1969 with a price tag of $47.6 million.

A dark side to a beautiful bridge

While the bridge is consistently ranked as one of the most beautiful in the United States, the Coronado Bridge is also ranked as one of the most tragic. The bridge ranks 3rd for number of suicides. (Golden Gate and Seattle’s Aurora Bridge at #1 and #2, respectively. Also, some lists have Coronado at #2 and Aurora at #3)

Over 400 people have committed suicide by jumping off the Coronado, and while help hotline numbers are posted along the bridge, the trend seems to continue. Folks in the area aren’t ok with that, and now the community is taking steps in 2017 to investigate if a special net could curb the number of people taking their lives on the bridge.

The Great Floating Bridge?

Like all great American landmarks, the Coronado Bridge also comes with a few urban legends. The most repeated is the idea Mosher designed the bridge to “float” if sections of it were knocked down. The logic? A floating bridge section could then be pushed out of the way and the Navy could still pass through the bay. Cool in theory, but completely false.

If you're one of the thousands of people driving across the Coronado Bridge today (or in the future), we hope you'll have a little more appreciation for the beautiful blue bridge in the bay.

Cover photo via Flickr


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