March 2, 2005

Nerf Balls to Go

EXHIBIT A TODAY IN "Why I love this medium" is this anecdote from The Doctor Is In's arfticle in his fascinating multi-part study of the Tacoma Narrows Bridge, "The Two Towers - Pt II:Concrete Thinking."

The author, Dr. Bob, usually writes brilliantly on medical and spiritual themes, so this series comes as a surprise and a pleasing one at that. In the midst of which comes this single startling factoid:

At the end of each pour, the pipes must be cleaned. The solution is ingenious: nerf balls. A section of pipe is removed near the pump, and several large nerf balls are placed inside. Water pressure is used to push these through the pipes, forcing the residual concrete ahead. When they arrive at the caisson, they are then returned through the now-empty pipe with high-pressure air. One non-official pastime of the crew is shooting the returning nerf balls from the hose near the pump; they sometimes travel 3-400 yards after exiting. One nerf ball thus launched ended up on the grill of a Mack truck driving over the bridge; it’s location is unknown, presumably in southern California.
And probably found its way onto a hillside in Laguna Beach where its weight was the final straw that brought it all down.

[HT: As the Top of the World Turns ]

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Posted by Vanderleun at March 2, 2005 11:25 PM | TrackBack
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AMERICAN DIGEST HOME
"It is impossible to speak in such a way that you cannot be misunderstood." -- Karl Popper N.B.: Comments are moderated and may not appear immediately. Comments that exceed the obscenity or stupidity limits will be either edited or expunged.

I'm exactly 1000 yards from the bridge right now. I can see the new concrete towers slowly reaching to the sky, topped by huge cranes, lit by work lights.

Have you ever seen the black and white footage of a bridge violently twsiting in the wind before collapsing? That's the original bridge..."Galopping Gertie" they called it.

G.G. was built before they knew about the effects of high winds on structures. The bridge was built in such a way that the flat surfaces acted like airplane wings.

The city of Tacoma had taken out a big insurance policy on G.G., but when they went to the city official in charge of paying the premium, he admitted that he had gone south with the money and had not paid the premium! He never thought that the bridge would fall down! OOPS.

The current bridge was made of steel and dubbed Sturdy Gertie. Lots of air flow this time.

The remains of G.G. are still down at the bottom of Puget Sound. I've walked along the shoreline and seen the twisted and snapped girders.

The State of Washington Department Of Transportation has several webcams of the bridge including ones that focus on the new construction.

Here's a link to the page.

Posted by: Mumblix Grumph at June 3, 2005 12:34 AM

Thanks for the link. I passed it along this morning. Good find for me.

Posted by: John Ballard at June 3, 2005 3:09 AM
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"It is impossible to speak in such a way that you cannot be misunderstood." -- Karl Popper N.B.: Comments are moderated to combat spam and may not appear immediately. Comments that exceed the obscenity or stupidity limits will be either edited or expunged.










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