Posted
In a Sept. 2 bulletin, German roller coaster manufacturer Maurer Sohne said stress testing of its "X-Car" ride vehicles, the coaster trains used in Hollywood Rip Ride Rockit at Universal Studios Florida, may not be "fatigue endurable." Universal says recent closure of the ride is unrelated.
Read more from The Orlando Sentinel.
delan said:
Water under the bridge, but don't the wish they went to B&M as originally intended?
According to whom?
Jeff - Editor - CoasterBuzz.com - My Blog
Bunch o'rumors, since the Japan park got a beemer that also goes around and over buildings, which means Florida obviously was getting the same ride ;).
I thought I remember reading they had four or five manufacturers bid on the ride and some of the submitted designs they deemed as not exciting enough, not high enough capacity, not enough room to build it, couldn't do a vertical lift, etc.
After riding HRRR, I agree, they should have went with a Beemer.
This is the Orlando Sentinel fishing for a headline again. It's also an example of why the manufacturers DON'T widely publish their bulletins. That said, with a little bit of digging, the Maurer-Söhne bulletin is available on the Web, and as you might expect, I have read it.
Maurer Söhne states in the bulletin that they have conducted strain-gauge testing and determined that the loads imparted to the coupling bars *may* exceed the design loads. Now think about this for a moment. The only way they could conduct such testing would be to run tests on an actual operating X-Car coaster. Service bulletins almost never identify the client who had the issue. The story makes it sound like Maurer Söhne is saying, "For the love of $DEITY, Universal, shut down your coaster before something bad happens!" when in fact there is a non-zero probability that it was Universal that discovered the problem in the first place. I don't know that it was, but Universal's testing and maintenance program is the sort that can ferret out an issue of this kind before it becomes a problem.
The way the bulletin is written also is careful to suggest that there have been no incidents so far as a result of this issue, and even implies that no cracks have been found yet. The requirement is for ultrasonic and magnetic particle testing at four locations on the coupler assembly (two drawheads and two ends of the coupling bar) every three weeks or 200 hours of operation, whichever comes first, until cracks are found or until Maurer Söhne issues an updated design.
For the curious: Magnetic particle testing will detect surface cracks in steel components, and the testing points appear to be around the bolt holes in the drawheads, and what might be weld points where the socket end attaches to the drawbar. Ultrasonic testing will detect cracks or other anomalies that are below the surface, and it appears that the location singled out for ultrasonic attention is a place where the other socket end pulls against the inner surface of the drawbar. I've not looked at the actual components, just at the diagram included in the bulletin, so there's a certain amount of conjecture here. But those of you who are engineers can probably recognize that the testing is on areas where strain calculations were probably performed at the design stage, and are areas where forces would tend to concentrate.
--Dave Althoff, Jr.
(I'm no engineer, but I kind of understand it a little. :) )
/X\ _ *** Respect rides. They do not respect you. ***
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The question I have is what they consider "practical test". I assume it's nothing more than physically testing the design in the lab.
If that's the case, what (other than over-designing) is to prevent a problem from reoccurring that (presumably) wasn't caught by "practical test" the first go-round?
Brandon | Facebook
Tekwardo said:
Bunch o'rumors, since the Japan park got a beemer that also goes around and over buildings, which means Florida obviously was getting the same ride ;).
Oh, kinda like Drachen Fire was supposed to be a B&M, because the element order was exactly the same...almost...not really. Well, they were almost the same color...
BUT THAT ONE IS TRUE!!!!1111!1!!!!1!! ;)
Brandon: The actual text of the bulletin indicates that, "...The existing loads can exceed the calculated forces in practice, having the effect that the coupling bar along with the coupling elements are not fatigue endurable. " What they are saying is that when they designed the ride, they designed the coupling bar around calculated assumptions about what the load would be. They predicted the load on the coupler assembly, applied a safety factor, and then designed the components to survive at that load and safety factor for 35,000 operational hours in accordance with ASTM F2291:9.
What happened is that once they got the ride built and opened, they put a strain gauge on the coupler and discovered that the actual loads are higher than what they had calculated. Apparently those actual loads are in fact higher by enough that they now have concerns about fatigue of the coupler components.
My GUESS is that some client noticed something that didn't look right, that led to a strain gauge test, and the result is the September 2 bulletin.
--Dave Althoff, Jr.
/X\ _ *** Respect rides. They do not respect you. ***
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Hmm, usually the safety factor (yield) would account for instances like this. If they are heralding possible catastrophic failure it looks like something was oversimplfied.
Tekwardo said:
BUT THAT ONE IS TRUE!!!!1111!1!!!!1!! ;)
Hey hey hey, don't poke fun :-) I too have my lemon chill contacts :-). Actually I heard from a few leads at Universal. Now I know the workers are not privy to such things, but I thought it was interesting that three different people told me the same thing.
I'd chalk that up to that particular rumor being spread pretty widely, and being somewhat difficult to discredit, much like the fatal Bat accident at KI (although the Drachen Fire rumor is admittedly more difficult to discredit than that of the Bat). My non-enthusiast friend, who grew up going to KI, was incredulous when I informed him a couple years ago that that never happened.
On a related note, I am amazed that in all the years that Drachen Fire stood silent at BGW, it never managed to kill anybody. :)
I mean, the Bat was only SBNO for a couple of years and everybody in the Cincinnati metro area knows somebody who knows somebody whose best friend's cousin was in the park the day the train smashed into a tree and killed all those people*. Heck, Demon Drop was never SBNO for more than a day or two at Cedar Point, and yet it isn't hard to find someone who swears that one of the cars flew off into the parking lot and smashed a '79 Civic**.
--Dave Althoff, Jr.
* never happened.
** also never happened.
--DCAjr
/X\ _ *** Respect rides. They do not respect you. ***
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Jeff said:
delan said:
Water under the bridge, but don't the wish they went to B&M as originally intended?According to whom?
That one is true.
Hi
RideMan said:
What happened is that once they got the ride built and opened, they put a strain gauge on the coupler and discovered that the actual loads are higher than what they had calculated. Apparently those actual loads are in fact higher by enough that they now have concerns about fatigue of the coupler components.
Thanks, Dave. I think I follow that.
What I'm wondering, though, 1) is the "practical test" simply running the train(s) with strain gauges attached (as opposed to simulating applied loads/cycling in the lab), and 2) if that is indeed what constitutes a practical test, why wasn't the practical test done on the initial design, or if it was done on the initial design, why the same practical test would now catch something that the initial test did not?
Brandon | Facebook
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