Personal Essay: Raising the Bayonne Bridge

New York City has lots of bridges, 2000 according toWikipedia,  but they must be counting fallen trees across flooded side streets because that’s way more than even I imagined.  2000?  Well, there are many and some of them are some of the most impressive spans in the world.  We are composed of islands, and we are over 8 million in population in the city with another 25 million in the suburbs, depending how you count suburbs.   A lot of people have to move about and cross lots of water: the Hudson River, the East River, the New York Harbor, the Long Island Sound, and the Kill van Kull.   

I live on Staten Island,  the most remote of the five boroughs of New York City, and we have four major bridges that connect us to the outside world, three bridges that connect us to New Jersey, and one that connects us to Brooklyn.  The Kill Van Kull is a channel that separates us from Bayonne, New Jersey, and as you can imagine a lot of shipping goes through that channel.  Spanning the channel is the Bayonne Bridge (they never name anything after Staten Island), which on certain times of the year I can see the top from my bedroom window.  I think it’s in the winter time that the trusses of the arch becomes visible, when the leaves are off the trees and I have an unobstructed view.  I’ve never considered the Bayonne Bridge to be aesthetically beautiful, so I’ve never thought much of being able to see it.  Houses on Staten Island that have views of the Verrazano-Narrows Bridge are very expensive; view of the Bayonne Bridge does nothing for my home value.

Apparently they will be building cargo ships well beyond current size.  They are currently huge, so what they will be building is like the largest mammal set side by side to a dinosaur.  Super container ships will be the transport vehicle of choice, as soon as they can build them.  This has caused ports around the world to modify their ports to accommodate these super vessels.  Dredging bottoms, widening harbors, building accommodating structures for loading and unloading are some of the projects going on for the sake of improving logistics.  You can read about that here. 

They have dredged parts of New York Harbor, either for this reason or just for some sort of maintenance.  But to really accommodate these super container ships, they will have to raise the roadway of the Bayonne Bridge.  The current clearance must interfere with the tops of these super containers.  So instead of tearing down the bridge, they will build the roadway above the current roadway, and then take down the old roadway, so that in the end there will be more clearance for the super ships.  

Does that sound interesting?  Absolutely!  As an engineer, that really piques my interest.  Building on top of an existing bridge is way more complicated and difficult than building one from scratch, or at least intuitively it would seem that way.  Here’s a video of the project plan.  It’s breathtaking.   

 

I wonder what the cost savings are for building on top rather than building from scratch.  That’s some heck of a project.  I’m a mechanical engineer, but projects like that might have swayed me back in college into being a civil engineer.  I would love to manage that project.  When they are into it, I’ll be sure to go by the bridge and take some pictures.  

Now one thing I don’t understand is how tall are these super ships?  From the movie clip it looks like there is plenty of vertical clearance.  However when I looked up the dimensions of the bridge, it claims there is only 14 ft (4.3m) clearance.  Fourteen feet to the water level?  That’s not even two stories.  It’s got to be higher than that.  It looks way higher than two stories when I’m driving on it.  

One last thing.  I work in New Jersey and though we (my carpool) don’t regularly take the Bayonne Bridge, we might switch to it on occasion when traffic at the Goethals Bridge is jammed.  We’ve decided that while this project is going on, we’ll suffer with the traffic and avoid the Bayonne.  A project that complex has got to have something go awry.  It will be a miracle if they execute the entire project flawlessly.  I hate to be the car under the beam that falls.