Another drop tower rope break!

Wednesday, June 11, 2008 8:37 PM
IntaminHater, you know what's funny? I was looking up stuff on RideAccidents.com and noticed not only a ton of deaths at Six Flags, MANY MANY MANY of them being on those inflatable water rides that go under waterfalls and stuff, but a lot of deaths and injuries at Paramount parks. I think in further review, it's just that as you get bigger and bigger, the stats are just more likely to show you have lots of accidents, when the odds are still ridiculously low that you will HAVE an accident at an amusement park. I also checked out Wikipedia and noticed approximately the same accidents recounted (some I had never heard of in the news though).

Also, you brought up an EXCELLENT point about the drop towers: If Intamin noticed that the cable thing could be a problem on their towers, why did they not recall the earlier towers or insist on the changes to the older rides? I know that once they sign over the ride to the park, their responsibility for maintenance of the ride pretty much is passed to the new owners of the ride (the parks), but still...seems negligent to me. Of course, if you think about a car that has a recall on it, do you HAVE to take your car in and have the possible problem fixed? No. You SHOULD, but you don't HAVE to. And in these cases, we have no idea whether or not Intamin issued a recall of their drop tower rides or suggested changes on them because it is likely that the parks don't absolutely HAVE to make those changes. In that case, that is completely and utterly the fault of the parks.

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Wednesday, June 11, 2008 9:23 PM
Sure parks may choose to change the item that needs replacing, or not. All the manufacturer does is say what they think should be changed, and give the reasons why. If the manufacturer feels strongly enough that these modifications need to be made, they will be able to convince the parks to make the modifications.

After the death on SROS the state of CA forced S:TE and Xcelerator to close down until they made the necessary changes. This was the first time the state had shut down and enforced changes based on an investigation outside of the state. And if it wasn't Massachusetts saying that they needed to be modified, would Intamin have changed anything in the first place? They seem pretty content in saying it was the operators fault, or that guest was too large. I'm not convinced they would have said that this needs to be changed.

Heres my problem. I feel that when these accidents keep taking place, and there are trends showing many similar situations on many similar rides, the manufacturer needs to take responsibility and do something. Intamin is always ready to pass the blame, and they rarely take proactive measures in fixing issues. The only time I can think that they were proactive and started fixing problems was in the early 2000s when they started adding supports to all their new rides that were gaining too many stress fractures. Sure they got to that right away, but it showed how poor of a designer they are.

Now we have here 3 instances where cables have snapped, one where someone was brutally injured. Do I need to fear going on these rides? Is there a possibility that this will happen to me? Sure, a very small one, that probably wouldn't affect my riding decision. Now is there a possibility that a cable snap will happen again? I'm confident that it will. Where and when, we don't know but it will happen again.

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Wednesday, June 11, 2008 9:38 PM
I'm just glad I don't LIKE drop towers. I don't ever get on them. Ever. I get on the upshot at Dorney Park, and I'm sure that if a cable snapped on that and wrapped around me and then the ride shot up, I'd DEFINITELY be dead, but that is absolutely the only ride like that I ever board.

I still think that even if Intamin issued recalls, there's only so much you can do to get a company to actually do something about those recalls. However, I do agree that they don't seem like they do enough to be supportive in not just the way they handle the parks, but also in the fact that they just don't seem to care about the families and the victims of these rides. Like, hey, we are noticing a pattern here, and Six Flags (or Paramount or whoever) refused our recalls, so we are, in the interest of safety for future riders, going to do something to get those rides investigated and fixed ourselves. And we're going to make sure our rides are idiot proof while we're at it.

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Wednesday, June 11, 2008 10:04 PM

redman822 said:


...your comments about Intamin installing automatic cable failure detectors - I do not recall hearing about this - can you provide a link to back this statement up?


I'm not sure about any retro-fit devices that were installed after the SFKK incident, but in later Giant Drop models there's a limit switch that runs very close to the spool in the motor room.

If the wire rope jumps off the spool at all, it engages the switch, e-stops the ride, and needs to be manually reset. While this isn't specifically for rope breaks, (it's mainly in case of an overlaying wrap, which could damage the cable) it certainly would still work in a rope-breaking incident, since you'd have backlash in the rope running back upwards, and that would e-stop the ride on newer models.

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Wednesday, June 11, 2008 11:09 PM

Raven-Phile said:

Super Loopy said:
Loopy - who's just not quite loopy enough to ride an Intamin drop tower.

...or any drop ride for that matter. ;-)

Hehe.



I rode Liberty Launch at HW. You just weren't there. :-P

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Wednesday, June 11, 2008 11:26 PM

kpjb said:

redman822 said:


...your comments about Intamin installing automatic cable failure detectors - I do not recall hearing about this - can you provide a link to back this statement up?


I'm not sure about any retro-fit devices that were installed after the SFKK incident, but in later Giant Drop models there's a limit switch that runs very close to the spool in the motor room.

If the wire rope jumps off the spool at all, it engages the switch, e-stops the ride, and needs to be manually reset. While this isn't specifically for rope breaks, (it's mainly in case of an overlaying wrap, which could damage the cable) it certainly would still work in a rope-breaking incident, since you'd have backlash in the rope running back upwards, and that would e-stop the ride on newer models.


That's what I meant, the other poster made it sound as if parks put the the automatic e-stop in case of this after the SFKK accident...
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Wednesday, June 11, 2008 11:37 PM
I was that other poster. I don't have any proof, but I do know that a device was installed in at least one location to detect this sort of malfunction. I know later models had this in place as well prior to the incident. Wish I could give some evidence to back this one up, but in this instance I can not. Take it or leave it, I understand.
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Wednesday, June 11, 2008 11:44 PM
S&S hasnt ever had any problems have they with their drop towers? Dont their drop towers run on compressed air or something that has to do with air power?
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Wednesday, June 11, 2008 11:52 PM
Yes, air is flooded into four tubes, pushing a cylinder which in turn pulls cables to lift/push the carriage up or down the tower.
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Wednesday, June 11, 2008 11:54 PM
S&S run on air power and magnets, but I've noticed that they also have cables of some sort. I don't know what those cables are for or if they are even something that the rides place stress on. Not sure...
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Thursday, June 12, 2008 12:32 AM
On the S&S rides, there are four ropes which are connected to the ride vehicle and to the operating pistons. On the S&S rides, the carriage is never disconnected from the ropes. As a result, if a rope were to break, the action of the broken rope would be very different from the action of the broken rope on the Intamin ride. Also, I suspect that a broken rope might cause an immediate overtravel condition on the affected cylinder, which would probably trigger something that the ride control system might notice.

Brian Noble challenged my comment about lubrication on the rope and wondered where I got that; it turns out that I may have overstated the case a little, but the expert testimony given in Appendix 34 of the KDA report is a fairly comprehensive examination of why the rope failed in the Kentucky Kingdom case.

Furthermore, IntaminHater noted the possibility that the ropes are breaking in a consistent manner, with a similar amount of loose rope below the break in each case. If you have a look at the aforementioned appendix, Mr. Genculu gives a pretty clear argument for the mechanism of failure, explaining why the rope failed in that particular location: the gondola is being lifted through the brakes, but is near the top of the braking section so the motor has reached full torque, subjecting the hoisting system to maximum load. This is the point where the rope is most likely to slip, and...get this...the point of failure is the point at which the rope is going through the hoisting sheave.

--Dave Althoff, Jr.

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Thursday, June 12, 2008 7:32 AM

Brian Noble challenged my comment

I wouldn't say challenge---I just missed it in the summary. Thanks for pointing at the right appendix.
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Thursday, June 12, 2008 9:33 AM
S&S drop towers do not use magnetic brakes. Some of their coasters do.
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Thursday, June 12, 2008 9:39 AM
I checked with Jeff, and the site that had the thread about the 2006 failure at Port Aventura is not one of the ones that he allows direct linking to...sorry folks.

But if you go to Google and do a search on this phrase:

"port aventura" "hurakan condor - out of order"

It should be the only link ....

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Thursday, June 12, 2008 5:48 PM

IntaminHater said:
A freak accident happening on an Intamin ride twice!!! That doesn't sound like the Intamin I know....

Knowing that Intamin's safety record is a hot topic at times, those that fight saying Intamin is a safe company one day will realize that patterns mean something...


The three incidents on the drop tower rides all have to do with the cables. Why aren't the parks replacing the cables overtime? They should be. Top Thrill Dragster was another cable. What do you expect at a ride that goes constantly at 128 mph. For Kingda Ka, it broke brake fins. Is that really an accident. For Superman, it was a person that was too big that fell out. You know how people are with hypers, and airtime rides. Maybe, the lapbar wasn't closed enough, and it happened.

For the white water accident at Texas, the water could have been too high, and the raft could have been top heavy. Maybe, bigger people were on one side of the raft, and it just went under. That makes sense to me. I don't get what really happened at the Animal Kingdom. California Screamin' crashed, and I heard that Disney was actually at fault for some reason, or another.

Of course, coasters crash. You have Mantis, Magnum, Demon, American Eagle, and Whizzer. Oh yeah. American Eagle is an Intamin. Why you would run 6 trains on Eagle is beyond me?

For Steel Venom, I have no idea what happened. That's about all the accidents I can think about considering Intamin.

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Thursday, June 12, 2008 10:18 PM
They *are* replacing cables over time. Even at SFKK---the report makes that clear.
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Friday, June 13, 2008 12:04 AM
(Brian, that technically *was* a challenge. Not necessarily in the antagonistic sense, but in the forensic sense. Just so you know that's what I meant. :) )

Indeed. But the maintenance instructions indicate that the ropes are to be visually inspected daily, given a detailed inspection monthly, and inspected by a qualified wire rope expert annually.

Spinout, the idea here wasn't to get into a whole litany of things that have gone wrong on Intamin rides. It does stand to reason that Intamin builds a broad variety of rides, and for that reason their exposure to catastrophic failure is unfortunately increased. There are other manufacturers who have a lot more ride pieces out there, but a lot fewer *ride systems* and as a result a lot fewer potential failure modes. Since you've brought up a whole collection of Intamin ride incidents, let me examine each in terms of what is known about them...

o Drop towers: This whole thread examines the drop tower incidents in great detail. Personally, I think one of the important points is not how frequently the ropes are replaced, but why the ropes are deteriorating so rapidly in the first place. The KDA report suggests that the rope suffered from both slippage and a lack of lubricant...probably because the lubricant had been removed from the ropes in an effort to reduce the slippage. Another issue I'd like to explore? Why did we not hear of any of these incidents until nearly a decade into the product life cycle? We know that the ropes at Kentucky Kingdom were replaced, in fact we know they were replaced ahead of schedule, from the KDA report. But the earlier ropes didn't deteriorate or break. Why is this a fairly recent development among these towers?

o Top Thrill Dragster: Dragster shredded its haul ropes in its first year of operation. Those ropes were supposed to last something like three years. On a new ride system, how do you expect to predict the lifespan of the components? That's why the winding drum on Dragster is so large, to protect the haul ropes. The design is supposed to be adequate, but something worked unexpectedly.

o Kingda Ka: My understanding is that this one did something weird, in that the drive system tried to drag the train through while the safety brakes were up; I've also heard that the cover came off the catch car track. The combination made quite a mess!

o Superman: There was no go/no go indication for the lap bar, the Darien Lake ride didn't even have seat belts when it had its incident, and for the New England incident, the lap bar wasn't properly secured. That's an operational problem. But at Darien Lake they had a similar incident but it was blamed on the lack of seat belts. Wait a minute; should the lap bar not be sufficient to restrain the rider? Might the lap bar system deserve a little scrutiny? Apparently so, given that it was redesigned for Millennium Force, redesigned again for Top Thrill Dragster, and that three different designs have been used on Expedition G Force.

o Perilous Plunge: Intamin said it was because the rider was overweight. Then the same incident happened to a much smaller rider on Hydro. Perhaps something was wrong?

o SFOT rapids ride: The drain in that raft was plugged, the float tube was underinflated, the attachment rope broke, and the leading edge of the raft (which was low in the water because of the underinflation and broken rope) caught on a weir designed to create rapids in the channel. That's what flipped the boat. That was both a design AND a maintenance issue.

o California Screamin': This was a very interesting case, and Disney issued a detailed explanation of the problem which did involve a non-Intamin-supplied part.

The other cases for the most part I am less familiar with, but you perhaps get the general idea.

In most incidents, there is a design problem, an operational problem, or a maintenance problem, sometimes all three. Where Intamin seems to get into trouble is when they assume their design to be infallible, blame an incident on some maintenance or operational factor, and then get hit with another incident in which the previously blamed factor isn't really an issue.

--Dave Althoff, Jr.

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Friday, June 13, 2008 1:14 PM
With the superman and hydro incidents, they just don't sit well with me. You can't blame operations if a guest is too large for a restraint. Do the employees have ways of magically deciding whether a guest is too large for a restraint? No the test method is to see if they can get the restraint to lock, if it can they are good to go.

Most modern day coasters don't all trains to be sent out until the computer reads that all restraints are indeed locked. So if a guest is able to fit within the restraint, and the computer system is allowing the ride to start based off of all restraints being locked, the operations shouldn't be blamed. The problem seems to be that the restraints design allowed guests to ride prior to sufficient locking. If an operator didn't check this, the computer system should not allow the ride to start with any open restraint.

Others can be blamed as much as you want, but right down to the core I heavily feel it is a design issue.

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Friday, June 13, 2008 2:03 PM
Just noticed something curious in appendix 31, page 16 of 20, the procedure for replacing the ropes. "Dismantle the rope supervising unit". When Technical German (which is the native language of the Swiss Intamin engineers) gets translated into English, what we would normally call "monitoring" gets translated into "supervising".
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Friday, June 13, 2008 4:21 PM
And your point, P&C? :)

Oh. You posted this same message in another forum, in which you also said:


Maybe part of the problem here is that at the end of the procedure, they never tell them to re-assemble the "rope supervising unit"?

Interesting point. That's the kind of response I would expect to come up with. :)

Now, moving right along, IntaminHater talks about one of the things that really, really, really aggravates me right now:



Do the employees have ways of magically deciding whether a guest is too large for a restraint? No the test method is to see if they can get the restraint to lock, if it can they are good to go.
Most modern day coasters don't all trains to be sent out until the computer reads that all restraints are indeed locked. So if a guest is able to fit within the restraint, and the computer system is allowing the ride to start based off of all restraints being locked, the operations shouldn't be blamed. The problem seems to be that the restraints design allowed guests to ride prior to sufficient locking. If an operator didn't check this, the computer system should not allow the ride to start with any open restraint.

Personally, I think this is a HUGE problem, and it is a problem that has been made WORSE by the actions of the ASTM committee. In the thoroughly botched (and increasingly discredited) Section 6.4.3 of Standard F 2291, the definition for a Class 5 restraint requires an external go/no-go indicator AND requires that the restraint system inhibit ride cycle start in a no-go condition. Unfortunately, the definitions for restraint classes 3-5 all require the final restraint position to be variable in relationship to the rider. This is, of course, completely insane. I cannot think of any reliable means by which a mechanical or electronic system can verify that an adjustable restraint is in a 'safe' position for any given rider. The only thing that can be reliably noted is that the restraint is in some arbitrary position, or the restraint is locked. The result is that if you have some kind of a detection system, you are going to accomplish one of two things:

a) You are going to insure that the restraint is locked, but that's all you can tell. You can't be sure that it is in a safe position for any given rider. What is safe for me may not be safe for another rider of a different build.

OR, if you really want such a system to contribute to rider safety...

b) You are going to detect that the restraint is in the loosest position that can safely restrain the smallest rider permitted on the ride

This is, of course, the only way you can use a go/no go system to actually determine whether the restraint is in a safe position. But look what that does: it means that your minimum "safe" position is *by definition* a minimum safe position *for all riders*. If you are going to do that, then why are we going through all this effort to make the restraint adjustable? We've determined that the restraint is safe for all riders in a particular position. Why not make that the locking position, eliminate all this adjustability crap, take the guesswork out of securing riders, and go back to 'binary' lap bars? That's effectively what we've got anyway, why not admit to it and get rid of all the guesswork and judgement calls? Either the bar locks or it doesn't, and if it locks you're good to go. Why can't we do that? We can't do that because somebody on the ASTM committee thinks that somehow a tighter restraint is "safer". As a result, the adjustable restraints (which were originally intended to accommodate LARGER riders) don't really help at all, and figuring out whether a rider is "safely" secured in the ride is little more than guesswork.

--Dave Althoff, Jr.

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