# 80 degrees for...Maybe 5 feet?

Wednesday, August 27, 2003 8:17 AM
I was wondering why do coasters have such gradual drops. I must say that Dragster does NOT have a gradual drop because 300 feet of its tower is vertical. But take MF for example, it says you drop at 80 degrees right?

Its only 150 feet of the ground and it is already flattening out.

My question is why are the drops on some coasters so gradual? I'd like 300 feet @ 80 degrees, I mean it just goes to 80 degrees for a few feet then starts to flatten out.

Anyone know why?

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http://sfdlmania.thrillnetwork.net

Six Flags Darien Lake Mania! Your #1 source for DL and other parks!

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Wednesday, August 27, 2003 8:18 AM
...because a 50' radius turn while traveling at 90 mph hurts something fierce?

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What do I Listen-To?
May the Schwarz be with you.

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Wednesday, August 27, 2003 8:19 AM

To reduce the amount of G-forces on the riders. Its as simple as that.
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Bob M.
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Wednesday, August 27, 2003 8:24 AM
To reduce the G-Forces on the body.

If the ride was 80 degrees for say, 250 ft, and then made a swift change of direction in less than 50 ft, the forces would be too extreme.

Take Wild Mouse coasters, for example. A Wild Mouse is a relatively slow ride, but the Forces can feel intense due to the quick changes in direction. Now imagine making that quick change in direction at over 90 mph - OUCH!

That's my quickie explanation...

(Looks like a few others got theirs up before I could hit "Reply"... Oh well)

:-)

*** This post was edited by djgreghaus 8/27/2003 12:27:34 PM ***

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Wednesday, August 27, 2003 8:25 AM
To have 300 feet at 80 degrees, you would need 500-600 feet of lift hill depending on the length of the train. This could be shortened some at the top if you used S&S's Flying Squirrel technology for the roll over, or if you went into the drop with some sort of diving loop/reverse Immelman. It's all about G's.
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Wednesday, August 27, 2003 8:31 AM
Ok i get it lol.

Now why is the drop down so gradual?
I realize the pullout has to be, I mean look at dragster the top goes over really quickly, its not gradual at all.

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http://sfdlmania.thrillnetwork.net

Six Flags Darien Lake Mania! Your #1 source for DL and other parks!

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Wednesday, August 27, 2003 8:32 AM
Also, getting to the 80º angle on MF takes a while, I believe, because of the fact the cable lift is traveling approximately 16mph, which is over double what a standard lift does (right?). If it was a standard chain lift I think it could have hit 80º earlier in the drop.

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You suck big time.
*** This post was edited by Legendary 8/27/2003 12:33:00 PM ***

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Wednesday, August 27, 2003 8:50 AM

Ride of Steel said:

Now why is the drop down so gradual?

Same reason, opposite direction of force. Go from MF's 45 degree lift to an 80 degree drop in short distance, and the negative G's would be, well, bad. Especially with a long train. The B&M hypers can shorten this distance because they have shorter trains:

http://www.joyrides.com/sfgam/full/raging_bull1.htm

And Ultra Twister can shorten the distance even more:

http://www.coastergallery.com/2001/AW32.html

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Wednesday, August 27, 2003 8:53 AM
Duh, Olsor, I didn't even take into account the angle of the lift was 45º! That would have much more of an effect on the longer radius at the top than the faster cable lift would. Good call by you.

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You suck big time.

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Wednesday, August 27, 2003 8:58 AM
I didn't drop out of engineering for nuttin'! :)

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Wednesday, August 27, 2003 9:03 AM
The most obvious answer to this (to me) would be because it's a parabola designed to produce a certain amount of Gs...

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Raging Bull is best when you're first. [6/16/03]

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Wednesday, August 27, 2003 9:32 AM
Coasters that reach the drop angle of 80° to 90° fast (Expedition Ge Force, Xcellerator and Dragster) use the siedeways twisting track as a means to keep the negative Gs lower.

At the point where people would really be affected by the "pullout effect" the trains yank you to the side, thus giving your behind contact to the seat again. This is a very clever, spectacular and funny thing to do.

We will see how the drop on the new Hershey Intamin will be designed, which will have a straight, nearly vertical drop.

See as well how S&S redesigned the hill on Dodonpa to reduce the negatives on the drop, compared to Hypersonic

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YEN! Not ZEN!

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Wednesday, August 27, 2003 9:46 AM
I personally like the gradual drop better. It just has a better feel, gettin steeper and steeper, not knowing how fast you are going because you are in freefall. Then you reach the pullout and the speed hits you all at once. If you want a straight drop without a gradually sloping hill, ride Magnum.
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Wednesday, August 27, 2003 12:16 PM
Actually, the slope of the lift hill has nothing to do with how the track is shaped after the top of the lift. It's really not important what shape the track is before the high point. The high speed of MF's lift is a big factor though, as well as the long trains.
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Wednesday, August 27, 2003 1:00 PM
especially since the body is only supposed to take about 1 or maybe 2 negative G's, whereas is can take in excess of 5 positive G's.
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Wednesday, August 27, 2003 1:49 PM
Jim Fisher, explain how a steeper lift hill (45º) vs a not-as-steep (25º) lift hill wouldn't need a larger pullout at the top to reduce negative G's. It seems like it would, but of course I don't know physics/egngineering all that well.

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You suck big time.

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Wednesday, August 27, 2003 1:57 PM
...well, it's all a matter of radius. Centripetal force is defined as F=m(v^2/r). As r increases for a given speed, F decreases. So, as the train is gaining speed as it crests the drop, v is increasing. To keep the F the same, r needs to increase as well. If the ride is traveling a further distance around an arc (from +45 to -80, for example), the train will be traveling faster at the end of that arc than if it were a smaller difference (i.e., +25 to -80) and thus, the rider would experience greater forces at any one radius.

The angle of the lift and first drop aren't as important as the speed of the train and the radius of the curve.

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What do I Listen-To?
May the Schwarz be with you.

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Wednesday, August 27, 2003 3:16 PM
The long gradual drop also gives the illusion of the track going past 90 degrees because riders can't see the bottom of the drop from the top. Dana Morgan stated this on the "Making of a Roller Coaster" show with SD2K.

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"This is everybody's fault but mine"

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Wednesday, August 27, 2003 3:37 PM
Also, if you're an airtime whore, you probably don't want a lot of straight track on your drop, unless it's vertical, or close to it. The whole beauty of your traditional, straightforward drop is that the curve of the track descends more quickly than the parabolic potential "flight path" you, as a rider, would take in freefall. If there's too much straight track on your drop, though, it allows more time for your "butt" to catch up with your "seat," which is the antithesis of airtime.

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