GD Closed?

[saberon]

At the end of the day the giant drop has been operating for more than 9 years without incident. It's well maintained and isn't even the same ride trade model as the american one. It's pretty silly to close it, it really is paranoia as Gazza said.

[New display name]

The manufacturer of the Superman Tower of Power says it did not supply the cable that sliced off a girl's feet at Six Flags Kentucky Kingdom on Thursday. The ride's cables and wire ropes would have had the need for replacement at least several times since the ride opened in 1995, but those replacement parts did not come from Intamin. The company says it has not supplied parts for the ride for 13 years. Inspectors from the Kentucky Department of Agriculture's Office of Consumer and Environmental Protection believe that the cable is to blame for the accident, but they are still trying to determine why the cable snapped and how it got caught around the girl's legs. The girl remains hospitalized, but there is no word on her condition So why is the media asking for the ride to be shut down. Facts – 1. Giant Drop & Superman Tower of Power has different cable systems that pull them to the top. 2. At no times do people come to close proximity to the cable on the giant drop. 3. The cable runs behind the gondolas of the Superman Tower Of Power. 4. The cables are supplied from different supplies. I understand why all the six flags parks would stop all there drops as they would get there cables from the same supplier. This is just a typical media beat up when they had no other stories to run. I did not even see it on the news till I saw the question get asked on this web site. (Richard)"But particular models of planes have in the past been grounded as a result of crashes. I'd say without much doubt that this is a freak accident, but I find it a bit of a stretch to call such a valid and justified precautionary measure 'neuroticism'. I can't see how it would make sense to keep them open until they can rule out with 100% certainty that it's not a design flaw." It can be ruled out 100% that it is not a design flaw by there being two lift systems and two totaly different designs.

Edited June 26, 2007 by skeetafly

[Gazza]

IMO, it would be more logical to close equipment that is known to use cables made by the manufacturer of the ones in use on Superman Tower of Power.

[Richard]

My point has been so completely missed here. I never once said Dreamworld should close the ride because it's unsafe. I've said several times that there is absolutely no reason to think there is anything wrong with Giant Drop. Dreamworld made the decision to keep the ride operating without any information available from the situation in Kentucky. I have no doubts that from a safety point of view they were well on top of it, but from a PR point of view they did take a hit that could have easily been avoided. As I've mentioned, they've shut rides in the past for similar reasons, which have gained media attention, but not to the extent, nor in the negative manner of this current story.

It can be ruled out 100% that it is not a design flaw by there being two lift systems and two totaly different designs.

Forces and wear and tear on the wire ropes for each system would be quite consistent with each other, taking into account that Giant Drop is taller and has heavier gondolas. The two systems are fundamentally identical. Certainly to the point where if there were a flaw with the SFKK lift system, there's a good chance it'd also exist on Giant Drop. When the incident occured, and when I made that post, no information was available to suggest anything about the situation - to myself, nor to Dreamworld. Six Flags and Cedar Fair made a call that saw similar (NOT identical) rides around America immediately shut until a cause was found. This does include drop rides that use the same winch lift system as Giant Drop. That is why this issue attracted any attention at all for Dreamworld; they made a gut decision which went against the gut decision made by two of the largest theme park operators in the world. A lot of you are also conveniently forgetting one very crucial thing in this entire situation. The problem here is not that the cable snapped - it is that in the process, it cut a girl's feet off. Cables on these rides snap. It's happened before and it'll happen again. This'll happen regardless of the lifting mechanism in place, because it comes down to fatigue, a result of general wear and tear. Tell me with 100% certainty that if the cable were to snap on Giant Drop, it couldn't do similar or worse. Kentucky investigators don't yet know what happened to cause the injuries.

[Gazza]

Its OK Richo, we did get what you said. If they had decided to close the ride for PR reasons then we perhaps might have only seen one line in a story (Might have been something like "As a result of the accident, several parks worldwide have closed similar rides, including a local ride, the Giant Drop at Dreamworld") Instead DW have had to grapple with media attention and dedicated stories about them from the Courier mail and MSN as a result of their decision, which they could have avoided. I think people were just talking about other aspects of the situation, related to the decisions of the American operators.

Edited June 26, 2007 by Gazza

[New display name]

I don't think Dreamworld kept the ride open on a gut feeling. I don’t know who told you that Dreamworld made the decision to keep the ride operating without any information available from the situation in Kentucky. Dreamworld is in the best position in knowing if the ride is safe or not and dreamworlds engineers would have had talks with Intamin and any supplies of the parts. The Forces and wear and tear would be different due to the fact that there would be more side contact on the cable from one system to the other. I do not think dreamworld should bow to the media because we know how many times they get it right or stretch the truth to get there ratings up. I don’t think that people will not go to dreamworld because the ride is still open. I too understand what you are saying Richard but I don't think the media is a good source of information.

Edited June 26, 2007 by skeetafly

[Richard]

I don't know who told you that Dreamworld made the decision to keep the ride operating without any information available from the situation in Kentucky.

No formalised reports have yet been released by Kentucky officials regarding the matter. The investigation didn't conclude until very recently (the past day or so), the findings of which are not yet known -- to anyone. A gut feeling is the culmination of years of experience; an intuition based on years of experience. You can quietly skip over the fact that Six Flags and Cedar Fair have shut down all similar rides pending the results of the investigation and suggest that Dreamworld is somehow more clued in in this situation as well as try to refute everything I say but the fact is neither one of us have even a small percentage of the facts relevant to the situation. You're trying to argue with 100% certainty that to do anything but keep the ride operating is foolish; I've been arguing that without all the facts, Dreamworld shouldn't have been so hasty and assertive in their decision to keep operating, and this has been reflected in the media. I thought I'd take one quote from the News.com.au article:

Dreamworld management said they were waiting for results of investigations at the US theme park however were confident "this type of incident could not occur at Dreamworld".

Now of course the media are out to misquote everyone out there and bend the truth and all, but they're waiting on the results of the investigation? Doesn't that strike you as a bit of an unnecessary risk?

[New display name]

I can’t see how can you say with the information available that it could be a design fault being that each system is a different concept. Do you know why only the American parks closed these rides when they are built all over the world? Why did some parks close rides that use cables that are not drops at all? The two systems are not fundamentally identical, they may get the same outcome but by manipulating the cable in different ways. The Giant Drop winches and the SFKK use a pulley and weight system. These two rides where made years apart and maybe the design has changed between this time. Dreamworld would know a lot of this information and would make an educated decision and it would not be made on a gut feeling. On Sunrise today the CEO did say that they are total different systems. The manufacture of the ride said they have not supplied any parts to SFKK for seven years and the cable had to be changed every couple of years.

[djsupersleuth]

Content below from: http://www.wsoctv.com/news/13548463/detail.html#"] May shed some light on how it occured however I wouldnt rely on it totally until an official report was released. "We seen the cable break loose soon as it got to the top on the right-hand side," said Chris Williams, who witnessed the event. Treva Smith said it snapped again as the ride descended. "The people on the ride just came and hit the ground," Smith said. Williams said she saw the teen maimed. "As the ride came down, the wire swung left, struck the young lady on the back side of my children," Williams said. Williams' daughter Amber said she gave up her seat to the 13-year-old and was sitting on the other side of the ride. Williams rushed toward the ride to find his daughter. As Smith raced to find members of her group, she said she made a gruesome discovery. "When I got up there, the lady, she was just sitting there and she didn't have no legs," Smith said. "She didn't have no legs at all. She was just calm, probably in shock from everything." Smith said she saw no blood and the girl wasn't crying, but the same couldn't be said for many who witnessed the incident on the ride formerly known as the Hellevator. Warning: Speculation below, read with care. This ride was a prototype from Intamin and was being built shortly before the Probe at Wonderland. One of the lessons they learnt by building this one first was the alignment of the guide rails which the cabins run on, after many attempts and many holes drilled in the tower (Swiss cheese apparently) they finally realised that aligning the rails and drilling was impossible to get right during the heat of the day and the phenomena of the tower "following the sun". Installing the rails took place at night when the sun had no influence. This unit is pretty much identical to the Probe other than it runs 5 gondolas opposed to Probe's 3. The winch system is housed in the top machine room and the twin ropes wrap 10 times around the twin drum system - one drum is driven by the gearbox and the other is purely a deflection drum to enable the rope to stand off the inside of the tower the required distance. The counterweight weighs as much as the cabin fully loaded (from memory about 1300kgs) The winch actually does more work lowering the catchcar after the cabin has released from the top as it is lifting the fixed weight of the counterweight without the balance on the other side (loaded cabin) Now pure assumption on my part but if one of the two cables broke whilst the cabin was near the top then the broken section - say 10 metres would fallover the front of the cabin and onto the guests which wouldnt really injure anyone too much (a bit like a punch in the head) but then if the cable twisted and wrapped into a loop around the feet of someone sitting there and the cabin releases from the catchcar to which the cable is attached to the top of well then you would have a situation where this may happen. One system which I would hope is in place there as was on Probe was a proximity switch sitting close to the cable which would trigger a E stop if it lost the cable ie: cable breaks and moves away from it. Anyway just a thought, feel free to pick it to peices!

[Gazza]

Something funny that I noticed:

The people on the ride just came and hit the ground," Smith said.

Umm, correct me if I'm wrong but wouldn't a few people be dead if they had "hit the ground", that part of the account sounds a bit made up, I'd probably wait for a more reliable account, its seems like the people they spoke to are those "I seen the tornado destroy ma trailer" types.

[Harrop]

If a plane crashes do they cancel all flights around the world. Typical American neuroticism. Sad to hear someone gets hurt on a ride, but as far as I am aware giant drop is still in operation as it's not listed in the in maintainence page of their website. Although I am still wondering how someones leg could be severed by a snapped cable. If the lift cable were to snap the gondola and the hook carriage above will fall but they'd still be attached and on GD they are both attached the the rails and would still hit the eddie current brakes as per normal the cable could hit someone I guess. not sure...

Well as an aviation student myself, if they do not know what went wrong, they will ground all aircraft models till the reason for the accident is established. Obviousley there not going to ground all aircraft types if its the pilots fault for flying the aircraft into the ground. Which reminds me, air crash investigation is on tonight

[saberon]

Even if the cable snaps, it will never ever 'hit the ground' as it will always pass over the eddie current brakes (ebrakes) and that will slow the gondola

[djsupersleuth]

Even if the cable snaps, it will never ever 'hit the ground' as it will always pass over the eddie current brakes (ebrakes) and that will slow the gondola

Correct, however in that situation it would hit the bottom buffers very hard as it would have the added weight of the catchcar (approx 250kgs) which added to a full gondola is far over the allowed weight. It would still slow dramatically in the brake fins but hit the ground with a definate thud. Now for this to occur BOTH cables would need to break at the same time and the chances of that are highly unlikely unless both cables had worn past use by and the second cable couldnt handle the load of the cabin by itself.

[rappa]

I don't know how much harder it would hit the rams at the bottom considering the added weight would equate to a faster deceleration (the very nature of magnetic brakes is that they act in an exponential type of curve) so the end speed probably wouldn't be all that different, just would be a much harsher deceleration. Similar to when the car is empty to when it is full of pax.

[djsupersleuth]

Yes but there is a point where the exponential limit flattens out and braking does not improve. Evidence of this was 4 very large maori fellas who took a ride on the Probe when the weight sensors were faulty, all 4 ended up with bruised tailbones.

[Gazza]

Djsupersleuth is correct in saying that a heavier gondola has the potential to hit the buffers harder. Basically you can link the equation E = vBl to F = BIL to show that the resistive forces on a conductor being passed through a magnetic field are directly proportional to its velocity (Im not going to show how I derived this since it is long and boring) F ∞ kv So what does this mean for Space Probe, or any other drop ride for that matter? Basically, the faster a gondola comes into the brakes, the more force that will act to stop them. Now, we should all know that gondolas will always hit the brakes at the same speed, no matter what the loading since all objects (when negating air resistance) accelerate towards the earth at the same rate. Since braking force is linked to velocity, and velocity only, that means the same braking force would be acting on the gondola. Because of this, everyone gets the same amount of force given them for braking, but unfortunatley for our aforementioned Maori friends they have a bit more weight force acting against the upward force from the brakes, so they wouldn't decelerate as quickly hence hitting the buffers harder. (since ∑F=ma , the upward net force would be lower, so deceleration would be lower)

Edited June 28, 2007 by Gazza

[pazzap]

Because, quite simply, it wasn't a western, 13 year old little girl who sustained the injuries, and that's the sad fact about the media. We're also talking about a spinning carnie ride, not a 100m tall drop ride. Don't really want to get into an argument so I'm stepping back

Not funny, the girl lost her feet.

Correct, however in that situation it would hit the bottom buffers very hard as it would have the added weight of the catchcar (approx 250kgs) which added to a full gondola is far over the allowed weight. It would still slow dramatically in the brake fins but hit the ground with a definate thud. Now for this to occur BOTH cables would need to break at the same time and the chances of that are highly unlikely unless both cables had worn past use by and the second cable couldnt handle the load of the cabin by itself.

and what about if the brakes fail? Haven't they done so on plenty of Intamin Coasters before? What makes a tower drop's braking system more reliable? What I am saying is, it's not foolproof. Guess it ads to the thrill in a drop ride.

[djsupersleuth]

What you do not understand is that the brakes cannot fail as they are non switchable therefore making them failsafe, foolproof whatever you want to call it. What makes it reliable is the fact that there are no moving components in the braking system, the permanent magnets (rotor) bolted to the back of the cabin are gapped for clearance to the fins (stator) bolted to the tower and there is no contact between the two. The permanent magnets can eventually weaken but this shows up in weekly weight tests performed by maintenance using weighted bags (usually sandbags).

[Gazza]

Not funny, the girl lost her feet. mad.gif

Sorry, what are you trying to say with respect to nev's comments? How was he making a joke? How was he having a dig at the girl?

Haven't they done so on plenty of Intamin Coasters before?

'Plenty' is a bit of an exaggeration, the only incident i know of is on Superman: Ride of Steel, you can read about it here: http://capital2.capital.edu/admin-staff/dalthoff/sros.html The difference is on roller coasters the brakes need to be able to open and close (eg the rollback brakes on SE) They used to also do it on the final brakes so the friction wheels would have to do less work to get trains out of the brakes when it was time to move the train (didnt have to put up with magnetic resistance) Now they have abandoned that approach and just have fixed brake fins mounted on a sloping section of track, and then a friction wheel at the bottom to physically stop the train. Edited June 29, 2007 by Gazza

[djsupersleuth]

My previous post was relating to drop rides only i.e: Probe, GD. Some of you would have picked that up, some wouldn't have.

[pazzap]

Sorry, what are you trying to say with respect to nev's comments? How was he making a joke? How was he having a dig at the girl? 'Plenty' is a bit of an exaggeration, the only incident i know of is on Superman: Ride of Steel, you can read about it here: http://capital2.capital.edu/admin-staff/dalthoff/sros.html The difference is on roller coasters the brakes need to be able to open and close (eg the rollback brakes on SE) They used to also do it on the final brakes so the friction wheels would have to do less work to get trains out of the brakes when it was time to move the train (didnt have to put up with magnetic resistance) Now they have abandoned that approach and just have fixed brake fins mounted on a sloping section of track, and then a friction wheel at the bottom to physically stop the train.

California Screaming is another one with brake failure and trains colliding. I didn't mean just Intamin (although CS IS Intamin)..although I worded it incorrectly. Just recently there was a collision with Arrow's MagnumXL, I mean, it does happen...Nice to know that a drop ride's brakes are foolproof. Thanks for the explanation. And regarding Nev's comments, it seemed very uncaring and indifferent to me, (highlighted by his own words that he was backing off before an argument started lol), but if I misunderstood, sorry Nev!

[nev]

And regarding Nev's comments, it seemed very uncaring and indifferent to me, (highlighted by his own words that he was backing off before an argument started lol), but if I misunderstood, sorry Nev!

I was stating the viewpoint the media would have on the situation, not mine, and yes, the media is uncaring and indifferent, so thanks for agreeing with me. And the backing off comment had nothing to do with that statement, hence the new paragraph - I was backing off from the topic as a whole because I could see an argument brewing.

[T-bone]

I can't be bothered reading the above posts, however I can say 2 things regarding the Giant Drop. I have just come back from holidays, and yes I am aware of what happened at SFKK, and so is the Park and it's staff, however as of last week the ride is still operating. The lines aren't very long either for it. The only time I spent in the queue house was waiting for the gondola to come back down, which was on a day where the queue for the TOT most of the day was close to the skull.

[Dreamworld Ride Op]

Dreamworld made an independent decision NOT to close the Giant Drop, and also defended it against media and other ride trades pressuring engineers into closing it down. I believe the reason that Dreamworld had such an individual response to the Six Flags disaster was that the engineers simply knew it was safe. Although people will go on about, "what if...", if a theme park was to run by "what if" regualtions, then no ride would be open. There is ALWAYS a risk, and any theme park buff is aware of that. Dreamworld simply decided to show that we are very firm on the concept of the Giant Drop's safety.

[Gazza]

Wait, so you are saying Ride Trade advised them to close it?