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New Jersey Officially Limits G-Forces on Coasters
Well, NJ has (sadly) become the first state in the US at limiting G-Forces on roller coasters. The regulation calls for prohibition of forces greater than 5.6 that last longer than one second. NJ gave itself the right to regulate rides after an accident where two were killed from a malfunction, not excessive Gs. (A ride I rode once -- It's a kiddie-sized coaster, not what you'll find at Cedar Point, OH. The two killed were a seven year old and her mother.) This is also despite the lack of scientific evidence linking G forces to brain injury, and 320 million riders who turn out just fine every year. One brain-injury specialist interviewed said that you can exert 10 Gs just plopping into a chair, saying the state was "a little misguided."
They had to fix the wooden coaster at Six Flags in San Antonio due to neck injurys.
The g-force limit is more for the coaster and less for the human. There is worry of machine failure, rather than brain damage. Besides, the 10Gs in a chair is an impulse force - the article isn't comparing apples to apples.
Plopping into a chair produces a very short pulse at 10G. That duration is key here. Most people will pass out in prolonged exposure to 10G.
Most "injuries" related to non-bruising/bone breaking G-forces are from blood deprevation. A really long, tight turn may be enough to deprive your brain of enough blood flow to cause you (or someone with poor circulation to start out with) to pass out. After passing out, you'll just flop around on the ride, where real injury can occur.
As for direct effects, we of course have the very unscientific number of "healthy patrons" which gives us some comfort with the current state. However, it isn't insane to believe that large exposure to prolonged, high-G roller coasters could pose real health hazards. Imagine if someone built a 10G sled that accelerated you linearly, then radially for say 30 seconds. Most of the people on the ride would have a hard time walking after, and many may have passed out.
Setting reasonable standards isn't a bad thing. If someone wants to build one faster or whatever, they could always file a variance with the locality if they could prove it was safe. This just puts their rides up to (more) public scrutiny.
Well, it depends a LOT on the nature of the force. Plopping into a chair is a force that the body is pretty well equipped to handle. Car accidents (suddent deceleration) can toss about very heavy G loads - 25 G's isn't unusual. A lot of auto safety now is figuring out how to mitigate those forces (airbags soften the forces relative to the dashboard) and how to redirect them into a more survivable form (why small children ride backward - we can take more G's from our back than our front)
5-6 Gs in the manner that rollercoasters deliver are pretty high (forces that an unsupported head will need to resist against). Sustained for even a few seconds and some people will pass out, and most people will be sore, and few will suffer significant problems due to pre-existing conditions. A CART race was postponed last year when drivers complained of dizziness and difficulty breathing with G forces around 5, though it was for fairly sustained periods.
I think the problem boils down to more people riding coasters, more high G coasters, and more people that aren't in sufficient shape to handle such forces. The number of injuries and deaths aren't high, but for an activity that is supposed to be entertainment, I suspect our tolerance for casualties is pretty low.
From the article:
G-force is the pressure put on the body when it is suddenly accelerated from a motionless position, resulting in a person's body being pushed back into their seat.
What the author just described here is half nonsense and half the wrong thing. Acceleration from any "position", motionless or not results in a force being applied to bodies going along for a ride. Secondly, the suddenness, or rate of change of acceleration, is jerk, not acceleration. G-forces are acceleration, not jerk.
That said, I personally think the regulation of the g-forces isn't really going to help much. Whenever I ride a rollercoaster, the sudden acceleration making my head knock into the supports is definitely the least fun part to me, and my guess is that's what causes the alleged brain injury, not sustained g-forces.
I might care if you can show me a link to that statistic. A quick Google search turned up a whole lot of nothing, except a Book Review of someone saying that sudden acceleration syndrome was B.S. in the Audi case and it was bad science. If your statistic is legit, then yes, I would care. But it looks like FUD, which is probably why you posted AC.
Although you are right that the mcdonalds case is a really bad example you are mixing it up with the Ford Pinto case. McDonalds made no such calculations, they just figured people wanted their coffee so hot that it would still be lip-searing good by they time they got to the office. No risk-vs-reward assesment was mentioned or even allegated during the McDonal's coffee case. But it was made clear that Ford did actively make such an assesment with the Pinto (or was that a Gremlin?)
Hold on to sixteen as long as you can, changes come around so fast, make use women and men.
Way less than one G. In order to have 1G or greater on takeoff you would need to have a Thrust-to-Weight ratio of greater than one. Believe me, no commercial aircraft have anywhere close to that. If I recall correctly, most are closer to .3-1 or so which translates to, at best, a .3G increase during the takeoff run.
Will
Gravitrons produce 3.8Gs for about 30 seconds. I believe this is permitted under NJ law.
Re: the accident: The was a chain dog failure ending in derailment [I believe]. Normal ride forces were not involved in any way, it's just a straw man used to push this law through.
No current roller coaster in the state of New Jersey comes close to a prolonged force of 5.6+ Gs. Or in any other state, either.
The law also puts some limits on lateral motion, which is not mentioned in the article. Again, nothing that would impact any currently existing coasters.
The trend in roller coasters is taller, faster, steeper, and tighter - which is good but only to a point. Sitting in the front of Nitro (at Six Flags Great Adventure in NJ) will always black out my vision in the large corkscrew. I haven't yet found a person who didn't feel extremely light-headed after taking that turn in a front seat. And that turn still isn't close to 5.6 Gs.
As for the lateral motion restriction, I applaud that. I know people who have bruised the sides of their heads on their harnesses. (The suspended Batman ride is pretty bad in that regard.) If rides keep progressing towards the extreme, some poor guy with weak neck muscles is gonna lose consciousness or even have his skull cracked. Safety limits are a good thing.
Anyway, this whole "its my body let me abuse it" uprising is pointless. The limits set by this law do not affect your ability to black out or sprain your neck. However, they just might save your life in 5 years when someone tries to build a coaster thats bigger and badder than it ought to be.
"Momentary" forces can be more destructive to the brain than sustained forces. the G forces imposed on your body in a rollercoaster are very gradual and slow, allowing your body to accomodate them. Your brain can't accomodate a spurius 10G force that happens momentarily as well.
Yup, I've seen a reproduction of the balance sheet from ford, numbers of deaths, injuries etc, all tallied up against potential liability, and then the bottom line calculation of cost of modifications needed to alleviate the problem. Truely shocking.
McDonalds made no such calculationsOK, I don't have any access to the evidence brought at that trial, so I shall defer to your greater knowledge. It remains, true, does it not, that the apparently excessive exemplary damages awarded in that case, were the result of McDonalds' failure to change their practices despite repeated injuries of a similar nature (presumably they felt that colder coffee would adversly affect sales). While this is not as shocking as the behaviour of Ford, it is not entirely dissimilar.
Better to be despised for too anxious apprehensions, than ruined by too confident a security. --Edmund Burke
Are you sure the deaths were because of SAS in the last year? According to an article on the Darwin Awards, there's been a total of 42 roller-coaster related deaths in the last 11 years. And I'm willing to bet that a vast majority of the cases were user stupidity, with the rest machine malfunction. Roller coasters are incredibly safe considering how many people ride them each year.
It's called Jerk. The rate of accelleration with respect to time.
I don't like the idea of Jerky roller coasters.
They make me feel as if I am getting punched.
I think I could stand higher Gs when the acceleration in longer.
I think the point is: Consider more variables!
I could probably find a way to kill somebody with a 5 G roller coaster, and have the same person live through a 10G roller coaster (though... I'd don't know for sure)
If I were subject to uniformed acceleration, it would be as if I were heavier... (I was going to say had a heavy body suite... but I remembered that the blood has inertia, and would like to stay where it is more than my bones witch are rigid so the blood could FLOW to the head or feet...)
Please use [ informative / summarizing ] SUBJECT LINES
Flame me here
http://www.miami.com/mld/miami/4068519.htm
Interesting... It seems they were just having a laugh at the expense of some busybody waitress... Paranoia rules!
Hate to say it, but you're dead wrong on the details of the incident. The ride you're referromg to is the 'City Jet' (http://rcdb.com/installationgallery402.htm?Pictur e=2).
The accident occurred on a ride called the 'Wild Wonder', installed in 1999, and removed later that same year. After modifications to fix the design flaw, that ride now operates at Magic Springs park in Arkansas.
What basically happened was that the car slipped backwards down the hill (after two diffirent safety systems simultaneously failed...) and the two passengers were ejected as the train rounded a very tight radius turn.
TODO: Something witty here...