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Rollbacks. Why?

Xpress

Strata Poster
Why would a ride rollback, specifically Intamin? Miscalculation on the computers part? Too light of a train? Too heavy?
 
A

Anonymous

Guest
They can only calculate "so much" since they really only have a rough weight figure of the train, temperature, wind, then you have all the other variables, sudden change in weather (cold/rain can increase friction by cooling the bearings), air resistance (people put hands in the air), the hydraulics aren't 100% equal every time, viscosity in the oil, etc.
There are so many slight variables that the computer can't monitor that can change the speed on the launch and make the ride roll-back. Also I think that the computer look at the last few launches and make the calculations based on these, then if there is too many changes it might not compensate enough...
 

lakeccrunner

Mega Poster
Not even computers are perfect. They fixed the rollbacks with Ka and by developing the overlaunch system. I can't say for certain that it never rolls back, because I don't know, but I know the system was implented to eliminate rollbacks, or at least eliminate the high frequency of rollbacks.
 

Antinos

Slut for Spinners
As already stated, it's all variance. Temperature, wind speeds, passenger weight, mechanics, etc all play rolls, and sometimes the physics just works out where there just isn't enough momentum to clear the top.
 

Mysterious Sue

Strata Poster
Lets get all GCSE physicsy

The kinetic energy (KE) of the moving ride has to be converted into gravitational potential energy (GPE) at the top of the drop, and back again to kinetic energy as you go down. For the train to reach the maximum height, it therefore needs the right amount of KE generated from the launch.

KE = 0.5*m*v^2 where m = mass and v = velocity

So the main two variables are the mass of the train and the speed at which the train is travelling.
But it's more complicated than this since the velocity is affected by friction from the track, drag from any wind etc. etc.

If anyone wishes to elaborate on this please do.
 

D1993

Hyper Poster
i know that dragster rolls back more than kingda ka. dragsters also gotten stuck twice at the top of the hill and with kingda ka there magnets on the top to make sure its at least pushed one way or the other.
 

Snoo

The Legend
Staff member
Social Media Team
^Those magnets are brakes.. they have no ability to move the train one way or another.
 

D1993

Hyper Poster
^ i probably worded it poorly thats what i meant that they prevent trains from getting stuck at the top. that would addmitedly be a really cool experience getting stuck at the top
 

Snoo

The Legend
Staff member
Social Media Team
Technically, brakes would only make the chance of getting stuck more probable, although the positioning of the brakes makes that kinda impossible.

But, something that has been mentioned.. somewhere on the boards.. the brakes on KK are only meant to slow down the train because of the launch speed. They intentionally launch the train faster to prevent rollbacks/stalls. Hence.. the brakes.

:D
 

kimahri

CF Legend
^ IIRC magnetic breaks can't stop a ride at all.

And Intamin aren't the only rides that roll back. Didn't some of us make a clown coaster somewhere and TPR did the same with a go gator?
 

mouse

Giga Poster
[youtube]http://www.youtube.com/watch?v=K2__FCC8iAM&feature=youtube_gdata_player[/youtube]
 

kimahri

CF Legend
Boomerangs also troll back all the time

troll_face___high_definition_by_animeburner-d3dcbnr.jpg


[/painful joke]
 

Pierre

Strata Poster
mouse said:
[youtube]http://www.youtube.com/watch?v=K2__FCC8iAM&feature=youtube_gdata_player[/youtube]

Ha, I remember that. And the ride op made Bicko of all people get off, the lightest of us all.
 

Xpress

Strata Poster
Fixed permanent magnets can't stop a train, but I feel there's a slight chance that LSM's or something can stop a train.
 

bizarrofan10

Hyper Poster
I prayed for a roll back when riding Ka and TTD and didn't get one; but the ONE time my friend rode Ka he got two roll-backs in a row.....
 

reddude333

Giga Poster
And I'm not sure about all parks but in most parks, even though a rollback may not be the intention of the attraction, the intention is usually at least to create the sensation that the train just might not make it over so they usually want to make it a close call (or at least feel like it is). It's the fear factor behind it. Thus, this allows for the occasional (or more than occasional rollback)
 

codyrisko

Roller Poster
I have never experienced a rollback, but I did make an epic call at Cedar Point. I pointed at the train and said that one is going to roll back and sure enough it did. A few people in line looked at me funny like I was somehow behind it.
 

lakeccrunner

Mega Poster
^^ Agreed. And I love to hear people freak out when it happens.

And damn, TTD was in rare form today. Actually got some good airtime in the front car over the tophat. Has never happened to me before. I was pleasantly surprised!

But I also had that disappointed feeling from not getting a rollback...I guess I should stop getting my hopes up for one.
 

reddude333

Giga Poster
^Yeah, I was only at CP for two days but I was really hoping to just at least witness one...but to no avail. Anyway, there must have been some tailwind today...
 

TTDfan52

Mega Poster
reddude333 said:
^Yeah, I was only at CP for two days but I was really hoping to just at least witness one...but to no avail. Anyway, there must have been some tailwind today...

Same thing happened to me.
 
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