Tuesday, April 16, 2019

Memorial Bridges over Piscataqua River at Portsmouth, NH

2013: (Bridge Hunter; 3D Satellite, 315+ photos)
1923-2011: (Bridge Hunter, the comments indicated it got listed as historic, but it was still demolished Feb 2012; Historic Bridges; no HAER!)

Postcard from Boston Public Library Flickr
I copied the satellite image because it caught cranes still working on the new bridge.
Satellite
February 21, 2012
(new window)   Watch about a minute to see how fast the river is flowing and how the captain guns the engine (turbo-lag smoke) several times to try to push the towboat out from the bridge. You can see the importance of having watertight doors, and having them closed. The crew saved at least one engine. At 5:27 we can see they brought in a couple of small boats. But evidently they are just assessing the situation. Or did they actually try pulling with the small boat? Skip the people shot and go to 8:29 where we see the arrival of the big tugboat that gets the job done. We also see the Sarah Mildred Long Bridge in the background. The tugboat has to be careful making her turn to make sure it also doesn't get caught by the fast river current. At 10:30 is when they actually start pulling on the line. And the line pulls the towboat at 10:40. It looks like the towboat did take in some water because, when it was pulled free from the bridge, it was listing to its port side.



According to Bridge Hunter, the old bridge had a rating of 87.7/100, but they tore it down anyhow! That means they tore down a bridge that was in good condition! One of the I-80 bridges in Joliet, IL, has a rating of 6/100, but it still holds lots of trucks because both BNSF and UP have relatively new, big intermodal yards south of Joliet.

A timeline of the old bridge has 8 images and a video of its construction. The lift span was floated out just as it was floated in 89 years before.

An HAER study was done for the Sarah Mildred Long Bridge, but not for this bridge. Because it was the World War Memorial Bridge, I would think this bridge is even more significant. Note that it was built in 1923, so it is a memorial for WWI. At the time of the construction and naming, no one conceived there would soon be another world war.

The new bridge.
Mike Garland in July 2015 from 2013 Bridge Hunter
Looking North

Mike Garland in July 2015 from 2013 Bridge Hunter
One of Nathan Holth's comment from 1923 Bridge Hunter:
Sometimes I feel sorry for how blind the general public is to the reality of the bridge world. These people apparently were led to believe that the replacement bridge would look as nice as the historic bridge. Only now, in the end, do they realize their grave error. This project is a perfect example as to why attempting to replicate historic bridges fails. If the community likes a historic bridge, only the preservation of the historic bridge is acceptable. HNTB thinks the replacement bridge is awesome because it is a truss without gusset plates. Great, that just makes the bridge look even more plain and ugly. You eliminate rivets, built-up beams, v-lacing, lattice, bracing, and what do you have left? A truss that is what I call a "Toothpick Bridge." A truss so plain and simplistic that it has lost the qualities that make a truss bridge beautiful.
http://www.fosters.com/apps/pbcs.dll/article?AID=/20111130/G...







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