Galloping Gertie

Misfit · Post by **Misfit** » Wed December 8th, 2010, 1:15 am

I just found this on YouTube. The stuff of Puget Sound legends I doubt it gets much airtime on out of area TV stations. This is the first Tacoma Narrows bridge during a wild wind storm in 1940. It has since been rebuilt. At least twice...

Although the last time was just to add a new span for more traffic - that old one didn't fail. Yet.

SonjaMarie · Post by **SonjaMarie** » Wed December 8th, 2010, 2:48 am

I've only been on the Narrows Bridge once in my life and so far that have been enough for me!

SM

Ariadne · Post by **Ariadne** » Wed December 8th, 2010, 2:59 am

I remember seeing that clip in high school physics class!

Misfit · Post by **Misfit** » Wed December 8th, 2010, 3:39 am

They showed this often in my school days. In film, mind you as other options were a thing of the future then

Ariadne · Post by **Ariadne** » Wed December 8th, 2010, 3:44 am

Yep, film - and a very jumpy film it was too, probably more because of the projector than the medium. The weird thing is I don't remember it being in color.

SonjaMarie · Post by **SonjaMarie** » Wed December 8th, 2010, 3:45 am

Amazingly the only casuality was a poor dog!

SM

MLE (Emily Cotton) · Post by **MLE (Emily Cotton)** » Wed December 8th, 2010, 4:15 am

They showed that in my engineering classes-- an example of what happens if you don't space the supports to interrupt and damp the harmonic wave. That first version of the bridge had piers positioned exactly such that each wave was reflected back down the span, gathering energy as they went.

That film is used in every engineering class that I know of. The other is a collapsing three-storey walkway in a Kansas City hotel where some clever budget-cutter decided that the whole could rest on one bottom nut and spacers, instead of the three that the design called for. (said budget cutting multiplied across many hundreds of walkway hanging rods.)

Telynor · Post by **Telynor** » Wed December 8th, 2010, 11:32 pm

[quote=""MLE""]They showed that in my engineering classes-- an example of what happens if you don't space the supports to interrupt and damp the harmonic wave. That first version of the bridge had piers positioned exactly such that each wave was reflected back down the span, gathering energy as they went.

That film is used in every engineering class that I know of. The other is a collapsing three-storey walkway in a Kansas City hotel where some clever budget-cutter decided that the whole could rest on one bottom nut and spacers, instead of the three that the design called for. (said budget cutting multiplied across many hundreds of walkway hanging rods.)[/quote]

Is that Kansas City skywalk the one that killed so many people when it came down? I remember seeing the footage of that one and just being horrified. The Tacoma bridge one is a classic -- thank goodness that it did not result in human casulaties. The one that makes me nervous to go over is the big one in Michigan, that one gives me the willies.

Misfit · Post by **Misfit** » Wed December 8th, 2010, 11:43 pm

I always get the chills going over that one in high winds, as well as our floating bridges. They've had a few *incidents* in high winds as well.

MLE (Emily Cotton) · Post by **MLE (Emily Cotton)** » Wed December 8th, 2010, 11:50 pm

Yes, the pontoon bridge over Hood's Canal flipped in a storm, didn't it? I got to know that one pretty intimately in my Vietnam-war protesting days, trying to block the munitions freighters going out of Bangor. Ah, youth and stupidity.