How do you move a 730 ton ball?

Or you could use a 1460 ton croquet mallet.

This was what they originally intended to do with the arch in St. Louis, but they never got around to installing the stake behind it.

Tom

 

That's kind of hideous, considering what was happening at the time to make that thing move, and it surprises me how much it's moving too... It seems like the people around are kind of oblivious to it too, which maybe attests to how well the damper works. I'm sure they all found out when they left the building.

 

LOL....true, but the 1003 ton pitching wedge would have been an option too....

You know that is seriously impressive though. Considering where that thing is in the building and how much the top of a building that tall would have wanted to move.

I'm really struck by a couple of things, like how well that damping system works. I've been in much shorter buildings during much less severe earthquakes and the motion is really pretty bad. It seems to have worked so well that no one noticed the building moving. Though I am shocked that no one really seems to have picked up on what seeing that ball move meant....

 

I am a seismometer!

I feel earthquakes even when most are oblivious. Often I can even tell which direction it is originating.

From here in Sacramento, I felt the Northridge (Los Angeles) quake, and a couple of the aftershocks . The Loma Prieta (SF Bay Area) quake made me dizzy! And I freaked my wife out a couple of times by mentioning feeling an earthquake and properly identifying its direction before any news reports. "I think it's in the Sierra - Bay Area - North Coast . . ."

That video of the building dampner is cool. Unfortunatey they didn't have the camera set at a wider angle so we could see how far the ball was moving in relation to the wall or walkway. Unfortunately, most videos of earthquakes involve the camera itself being shaken around. - Some day we will get a cool video of a large earthquake taken from a hot air baloon or other detached platform. That should show the actual movement and intensity.

 

Other than actual collapse I'm not sure the swaying of buildings and other structures would be visible. That ball was small relative to its surroundings so its relative movement was very apparent; but seeing the relative deformations of large structures would be subtle if visible at all. I recall during the Loma Prieta quake the only visible indications in the building I was in were the front glass doors swinging on their hinges (and the power lines outside swaying and arcing with a loud snap), but except for those and of course the FEEL and SOUND of the earthquake there were no visual cues anything was going on. Observed from on high I think what would be seen is abrupt collapse here and there, and rifts suddenly rending the ground in places (which would certainly be dramatic and frightening), but not any visible shaking or swaying.

 

that's one amazing piece Loma Prieta was strange... as a kid i thought it was a tractor closing on on the house.. too many movies...