Coasters to Face G-Force Limits?

jonerik writes "NBC News is reporting that today New Jersey will begin examining the possibility of placing limits on roller coaster G-forces. Pointing out that the G-forces on coasters are considerably greater than even those experienced by astronauts and race car drivers, legislators on both the state and national levels want to start reining in coaster G-forces which have been blamed for a number of injuries and deaths over the past few years. Pansies. Why do they think people ride roller coasters to begin with?"

Comments

G-forces.

[garcia]

I have ridden a few roller coasters in my life. Mostly in parks in OH and PA. Nothing to make a sweeping generalization, but I will anyway.

I went to Cedar Point in OH a few times and I have been to various other parks in the past 10 or so years. Last summer I went to Kings Island in Southern OH and I had the strangest experience on a roller coaster ever.

I rode Face-Off w/my gf. After the ride both my gf and I felt dizzy and disoriented. I wasn't as bad as she was, she had to sit for about 20 mins to regain her composure. I was definitly not stable on my feet and seemed confused mentally, very strange.

Was this a result of the G-Forces or something else?

I don't suffer from motion sickness on any other ride, and I have never been physically ill by any amusement ride.

Anyone have a similar experience riding Face-Off?

Re:G-forces.

[Lokni]

I had a similar experience riding Goliath at Six Flags Magic Mountain in Valencia, CA. I was completely dissoriented and needed help getting out of the ride. In addittion to that my vision greyed out around the fringes on one of the high G parts, the rising corkscrew part of the ride. I enjoy roller coasters but will not get on that ride ever again. Just to make a point that these things happen to everybody, I am a perfectly healthy 20 year old male.

Re:G-forces.

[Skyfire]

G-forces, in themselves, will almost never make you sick. Its rapid changes that will make you sick. About the only thing that G's higher than one will do to you (steady, no rapid) will make you blackout. Of course, if sustained for too long, death can result, but for that you need a momentary force of around 90-100 G's or a sustained force of around 10 G's. What's worse, in my opinion, about some rollercoasters, is the vibrations (usually older rollercoasters). Some of those are really painfull.

Of course, some people can get sick by anything. Motion sickness is something that is very hard to generalize about. The only thing that really gets me sick is rapid, repitative changes in altitude on a hot day.

Re:G-forces.

[KernelHappy]

The Viper (a relatively new steel coaster) at Six Flags Great Adventure is horrible in terms of comfort. The ride isn't that exciting and thanks to the design of the shoulder restraints most of the ride experience is liken to being repeatedly punched in the ear.

Your comment kind of simplifies the human bodies ability to withstand G forces. I just finished watching a whole program on the Discover Channel about crash testing and the effects of certain forces on the human body, so obviously I'm now a certified expert. Moving right along the program just reinforced what common sense would tell anyone who has been in any kind of accident: it's not just how hard you hit, it's how you hit, what position you're in when you hit, how many times you hit and the angle that you hit at.

The numbers you mentioned sound a bit off from what the program was stating in terms of what the human body could safely endure. They showed a man traveling at some thing like 630mph decelerate to zero in about a tenth of second, which worked out to roughly 45Gs horizontally. His lung(s?) collapsed and his retinas temporarily detached. He eventually recovered and managed to live another 45 years but its still not what I would consider a fun day at an amusement park.

The program also went on to state that the human body can only survive 15Gs of momentary force vertically before the spinal damage occurs. I wonder what 6Gs of sudden momentary lateral force would do to someone's neck.

It would also seem that human anatomy would play a big role in what forces and change in forces the human body could survive without damage. A person sitting perfectly upright may be able to survive a 6G load in one direction, but what happens when they are subjected to the same force with their body and head are shifted to one side from the previous 4G turn or loop? I sure as hell don't know, I doubt New Jersey state legislators know either.

Rider operators do not want to kill customers, just momentarily make customers think they are going to die. There are so many variables in play that any legislation that tries to "make these rides safer" is going to fail hopelessly. I'm all for making ride operators/builders prove that their machines are minimally dangerous but to put blanket limitations on them just doesn't seem to do anyone much good.

Re:Deaths?

[nucal]

This site on Amusement Park Accident Reports was a bit of an eye opener.

Re:Roller Coasters in Jersey

[CaptainSuperBoy]

there have been a number of deaths (actually, usually at least one every summer)

I don't know.. according to the report on the congressman's page, there has only been one death ever in NJ, and the victim was medically predisposed. Now I think that's only brain injuries, but this page doesn't list much in NJ either, and most of it is due to people not using the safety bar.

Check your facts before you pass on anecdotes as truth.

McDonalds Coffee incident

[alphaseven]

Its similar to the stupid McDonalds Coffee incident.

Hey, that poor lady needed skin grafts, they shouldn't have been serving coffee that damn hot. If they just offered to pay for her medical bills they could have avoided the whole thing.

McFacts about the McDonalds Coffee Lawsuit

Aside from that, I agree that this roller coaster law is stupid, but if you know the facts of the coffee case its a bad example.

Re:There really is cause for concern

[jheinen]

"potentially harmful effects of large gravitational fields"

Roller coasters do not generate "gravitational fields." They generate no gravity whatsoever. The do create acceleration forces which cause effects similar to gravity, and we actually know quite a bit about those forces. Fighter pilots regularly undergo forces of up to 9 Gs, and this is an area that the military and NASA have studied extensively. They have things called "centrifuges" which can subject people to very high accelerations. All fighter pilots spend time in the centrifuge learning how to handle high G loads.

As for your cousin, I suspect he had some other nascent condition which the ride exacerbated. The fact is, you're probably more likely to be hit by lightning than to be hurt on an amusement park ride, and no one is saying we should make it a crime to go outside in the rain.

Re:Roller Coasters in Jersey

[ZenCrawler]

i'm not so sure how complete that site is for accidents. I remember I was back at Great Adventure back in the late 1980's.. hrm I was in middle school so it had to be like 87-88. A girl let the ride 'lightning loops' restraints close behind her, and was ejected from the ride mid loop. She died from that and its not listed anywhere on that site. Also stories are on the news a lot about the Boardwalk rides like one 'wild mouse' roller coaster that had a 60 degree climb or so and the climbing mechanism broke and people went down and hit a car behind them causing some horrible G forces i'd assume, but I ride roller coasters a LOT myself and I say leave the G's alone..

More G force than Astronauts? Well, yes but...

[RockyMountain]

As a former aerobatic pilot, who frequently flew between -4 and +6 G, I'm familiar with this subject matter. I'm no longer active in this sport because of inner ear dammage, probably unrelated to the aerobatic activity.

Space launches have steadily reduced their peak G forces over the years. During the Mercury and Gemini programs, the Astronauts were exposed to as much G force as modern jet fighters do in a dogfight, and for as long. The heavier Saturn launch system of Apollo was gentler, and the Space shuttle is very tame by comparison. Russian cosmonauts still get a better (in roler-coaster terms) ride than their American counterparts.

Given how tame the shuttle is, maybe it's technically true, if misleading, to say that roler coasters give the rider more G that an Astronaut experiences. (They did after all say "astronaut", not "cosmonaut") A space shuttle jockey, just barely goes over 3G. Some roler coasters may peak at 5. But here's the difference: The shuttle sustains the 3G for the entire duration of the post-SRB-separation boost. That's several minutes of continuous burn. I doubt whether any roler coaster ever peaks over 3G for more than 2 or 3 seconds at a time, if that.

The physiological risks associated with high G are not determined by the magnitude of the G alone, but mainly by other factors:

The duration that high G is sustained. Long duration deprives the brain of blood long enough to cause very bad things to happen. No real risk there on roler coasters.

The onset-rate. How suddenly the G force starts and stops. High onset rates cause all kinds of problems, including back and neck problems, inner ear problems, and even brain dammage in extreme cases. Once again, no issue in a well-designed roler coaster.

Head movement. High G forces, especially combined with high onset rates, are aggrivated by sudden head rotation. This can be a problem even if the G forces are only momentary. Inner ear problems can result. Roller-coaster designers have little control over this factor, so perhaps it is a real concern.

Negative G. (Negative means the blood rushes to your head). High negative G can cause all kinds of problems, including burst blood vessels in the eyes. I've personally never heard of a roler coaster that goes beyond about -0.5G or so, and even then for less than a second, so I doubt that this is an issue.

Sudden transitions from positive to negative, or vice-verca. All the bad things associated with high positive G are accentuated if it immediately follows a period of negative. And vice verca if negative follows a period of positive. This will become a real issue if roler coasters ever start exploring the negative regime. Frankly, I doubt that they will. The average rider views positive G's as exhilirating fun, but would find negative to be obnoxious and uncomfortable.

Frankly, I'm much more worried about the structural design and maintenence of the coaster than the G-profile. But then, I've flown to WAY higher positive and negative G forces than either roler coaster or space shuttle experience, and I know the breathing techniques, and I know to keep my head relatively still. Roler coasters all seem really disappointing to me.

Re:Roller Coasters in Jersey

[TurboThy]

She died from that and its not listed anywhere on that site.

<quote> Wednesday, June 17, 1987 - A 19-year-old girl was killed after falling from the Lightnin' Loops shuttle loop roller coaster ride at Six Flags Great Adventure theme park in Jackson Township, New Jersey. An investigation by the State Labor Department concluded that the ride itself was operating properly, but that the ride operator started the ride without having made sure that all of the passengers were secured by the safety harnesses. The Department's Office of Safety Compliance further concluded that the accident would not have occurred had proper procedures been followed. The park was found to be in violation of the Carnival/Amusement Ride Safety Act and was subsequently charged with the maximum state fines of $1,000. The ride was reopened on Saturday, October 10, 1987, with the permission of the Labor Department, but was eventually dismantled and no longer operates at Great Adventure.</quote>

Nothing close to astronauts

[Scratch-O-Matic]

Not to have their bodies exposed to more forces and danger than most astronauts ever experience

From the original post:

the G-forces on coasters are considerably greater than even those experienced by astronauts and race car drivers...

I flew military jets for 9 years, and I think these comparisons are crap. When people used to ask me how jets compared to roller coasters, I would tell them that the two experiences are totally different. It's a matter of scale. Sustaining 4G or more for even 10 seconds, let alone 30 or 60 seconds or more, is an experience that simply cannot be reproduced by any rollercoaster that can fit in a theme park. The effects of the sustained G are DRAMATICALLY different than the one or two second hits (or three or four...whatever) felt on a high performance rollercoaster.

I recently road with my brother on a rollercoaster that I considered to be quite exciting, with corkscrews and consecutive loops, and when it was over he asked me how many G's he thought we had pulled. Based on the sensations I had felt (compared to my years in jets) I guessed 1.5-2. I was surprised to see a brochure later that claimed the ride pulled 6G. The two or three second hits just didn't have time to register.

Another example: a person using an ejection seat pulls an ongodly amount of G -- something like 30 or 60, although the actual number escapes me. Obviously this is enough to kill a man, but the brief time period involved make it survivable. I've known people who ejected and were able to walk around with no problem immediately afterward.

The point is that comparisons to astronauts and race car drivers is misleading. The maximum G must be examined only in conjunction with the period of time over which the G occurs. Brief hits DO NOT COMPARE to sustained G. Maybe rides should be limited and maybe they shouldn't, but the forces faced by astronauts are not part of the debate.

Re:Nothing close to astronauts

[DuBois]

As an aerobatics pilot who routinely pulls 6 Gs for a second or two at most, I suspect roller coasters are somewhat less than that, and the Gs last for only fractions of seconds rather than a second or two. I've never blacked out at 6 G's but have seen grey edges on my vision. There is a phenomenon called "The Wobblies" that can happen to dehydrated aerobatics pilots. The cilia of the inner ear get hypersensitive during dehydration, possibly because some salts that are normally in solution in the inner ear precipitate out and irritate the cilia. So, if you want to avoid the wobblies, drink up!

Re:Great...

[pmc]

Yeah - and people who get stoned are really good drivers, too, I suppose?

Well, for some value of really good - see this for details.

Here is a paragraph from the report referenced:

Third, the style of driving performance after consumption of cannabis can be interpreted as cautious. Evidence of increased caution includes fewer overtaking attempts, larger distances required for overtaking, slower speeds, and larger headways. This caution can describe either the behaviour or the strategy of the driver. For example, cautious behaviour may arise without deliberation as a result of alterations in perception and control (e.g., distorted perception of time and space). Alternatively, a driver may decide upon a deliberate strategy to act cautiously by adopting a reduced threshold of acceptable risk. This decision may be motivated by the recognition of performance impairment. Of course, neither basis is mutually exclusive; changes in behaviour may be a result of both (unconscious) psychomotor impairment and (conscious) cognitive strategy.

Re:Positive and Negative

[Noel]

In this context, positive and negative Gs are relative to the body orientation: positive Gs are directed from head to feet; negative Gs are directed from feet to head.

In physics, there may be no difference between positive and negative Gs, but there are definite physiological differences in how the body reacts to positive and negative Gs, and how much the body can tolerate in each direction. Like the previous poster said, negative Gs cause increased blood pressure in the head, which can lead to bursting blood vessels. Contrariwise, positive Gs cause decreased blood pressure (and flow) to the head, and can eventually cause blackouts.