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View Full Version : California Shakin' ?



V.I.N.CENT.
12-14-2007, 07:48 PM
Last week I was standing at the carousel next to the entrance to California Screamin' and noticed that each time a car went through the loop, it would sway back and forth for quite some time afterward. Anyone notice this before? Last trip was two years ago and I did not notice the swaying.

bassett1976
12-14-2007, 09:01 PM
If I'm not mistaken, they have changed one of the supports while the new attraction building has been built. This might have something to do with the shaking.

LuckyFin24
12-14-2007, 10:16 PM
Almost all steel coasters sway and move a bit, it's nothing to worry about. You just viewed it at an angle that really showed off the movement.

Burnt Toast
12-14-2007, 10:50 PM
Exactly... metal coasters have to have a little bit of give on the track, otherwise it will break apart from the forces put onto it.

Simple physics.

BGLeduc
12-15-2007, 05:02 AM
Last week I was standing at the carousel next to the entrance to California Screamin' and noticed that each time a car went through the loop, it would sway back and forth for quite some time afterward. Anyone notice this before? Last trip was two years ago and I did not notice the swaying.

I definitely noticed it before.

I don't do Screaming, but while waiting for my wife to ride, I watched the loop and did see it sway slightly. I first noticed in 2005, so I would not say it is anything new.

Brian

V.I.N.CENT.
12-15-2007, 11:48 AM
Almost all steel coasters sway and move a bit, it's nothing to worry about. You just viewed it at an angle that really showed off the movement.


Yeah, I have noticed it with other costers before. Never this noticeable. Was standing in the same spot two years ago and it did not shake ase much. I clearly remember standing in that spot becuase it is near the bathrooms and I was waiting for my wife :)

CV12Pirate
12-17-2007, 07:11 AM
They should all have "X" amount of flex. Too much flex leads to stress cracks and fractures. That is why they have to x-ray the steel in addition to (walking the track) visual inspection.

As a retired Quality Engineer (inspector), I am confident their team know's procedure, and has been trained and certified to use the equipment.

Now let us pray.

darph nader
12-17-2007, 07:37 AM
They should all have "X" amount of flex. Too much flex leads to stress cracks and fractures. That is why they have to x-ray the steel in addition to (walking the track) visual inspection.

As a retired Quality Engineer (inspector), I am confident their team know's procedure, and has been trained and certified to use the equipment.

Now let us pray.

That's what I like. TOTAL confidence.:eek:

ralfrick
12-17-2007, 08:23 AM
Ya shoulda been walking on the Golden Gate Bridge when they closed it for the 50th anniversary. There were a lot of folks that apparently don't know these structures are designed to move.

A bientot.

CV12Pirate
12-18-2007, 04:25 AM
Ya shoulda been walking on the Golden Gate Bridge when they closed it for the 50th anniversary. There were a lot of folks that apparently don't know these structures are designed to move.

A bientot.

I was on the bay that day. There were so many people on the bridge that it actually went flat. No arc! You should have seen it, scary.

DianeM
12-18-2007, 07:53 AM
I was there, and I didn't find it frightening at all. It was actually inspirational. It was so crowded that you couldn't move, but people cooperated to help others, so there wasn't a "crush". I hated crowds, even then, but I don't recall a feeling of "crowd" so much as a feeling of comraderie. I remember people clearing path's so that somebody who was ill could get through the crowd, and girls standing on the side of the bridge singing commerical jingles. We didn't know about the bridge bowing until the next day. Nobody had cell phones back then. It's a bit sad that they'll probably never do it again.


I was on the bay that day. There were so many people on the bridge that it actually went flat. No arc! You should have seen it, scary.

CV12Pirate
12-18-2007, 09:49 AM
I was not on the bridge, I was on a boat on the bay and had a great view. As an Engineer it was scary to see a bridge designed with an "arc" have a "flat spot".

Calculations started running through my head. Those same calculations were performed by Caltrans Engineers and that is why they won't do it again.

I am fully aware that people on the bridge were not scared. They were in party mode.

Trust me, if you saw and understood the calculations, you would be scared.

Bolivar
12-18-2007, 10:13 AM
I was there, and I didn't find it frightening at all. It was actually inspirational. It was so crowded that you couldn't move, but people cooperated to help others, so there wasn't a "crush". I hated crowds, even then, but I don't recall a feeling of "crowd" so much as a feeling of comraderie. I remember people clearing path's so that somebody who was ill could get through the crowd, and girls standing on the side of the bridge singing commerical jingles. We didn't know about the bridge bowing until the next day. Nobody had cell phones back then. It's a bit sad that they'll probably never do it again.

Wow what a different experience. I guess there were little microcosms in different spots on the bridge because my experience was completely different. No one was scared of it collapsing because no one knew about the loading until we saw it on the news later, but people were packed like sardines and when The crush coming south met the crush coming north it wasn't pretty. People were getting scarred by the crush, some were just getting mad. I saw people grabbing other people's bicycles and tossing them over the side. No one could move and everyone seemed to just want off.

bigrockstar
12-19-2007, 12:12 PM
Please don't hate me for this little diversion, but you should check out "Tacoma Narrows Bridge Collapse" on You Tube or Google Video. Totally wicked footage of the bridge they used to call "Galloping Gertie" because of it's poor construction in regards to sympathetic resonances. Now that's what I would call unsafe swaying!

Anywho, I never noticed the loop swaying on Screamin' but it sure wouldn't surprise me. That's quite a bit of kenetic force it exerts on that structure.

CV12Pirate
12-20-2007, 03:36 AM
Galloping Gertie galloped because her sides were not vented, they were solid. Because of that, the bridge acted like a wing (air going over the top at a different speed of the air going under the bottom causes lift) and attempted takeoff but the cables held her back. Causing the "gallop".

That is why you will see rails or post's on the sides of bridges instead of solid walls.

Post Script: I am talking about Suspension Bridges.

bigrockstar
12-20-2007, 12:00 PM
Thanks for the correction! There's lots of possible reasons people have posted on the web, and I'm naturally drawn to the ones with big words like "mechanical resonance!" :)