Fury 325 closed due to fractured support

Interestingly, the Charlotte Observer has this quote:

"Ohio-based Clermont Steel Fabricators is known for making Bolliger & Mabillard roller coasters. On Wednesday, president Daniel Crumbaker said the company is not part of the repair, and declined further comment."

Read more at: https://www.charlotteobserv...rylink=cpy

Maybe this was "technically" true yesterday, and a purchase order placed after that quote was made?

eChameleon:

I was wondering; is the only reason we know Clermont does work for B&M is because one day people saw track outside their plant, or did someone at some point in an announcement go "oh, by the way, the track is being manufactured by Clermont in Ohio"?

Every new B&M is spotted outside of their facility before installation, for as long as I can remember. And various media days, parks have announced (especially Kings Island, Cedar Point) about the locally fabricated track at Clermont. It's no secret.

As mentioned previous, I do some work with Clermont on non-coaster stuff, and the facility is loaded up with B&M columns, track, lift assemblies, etc...

Jeff has a video somewhere of Gatekeeper being manufactured, including the large entrance structures and all that, too, from inside Clermont.

Just wanted to say bravo to Carowinds for that official statement, such a refreshing bit of transparency in an industry that seems to go 🤫🤫🤫 everytime something breaks or goes wrong (looking at you, Great Adventure. And more recently, Worlds of Fun)

Addressing and reassuring guests about an issue that pertains to their safety in this detailed and professional of a manner; I don't think I've seen anything on this level in recent years, even amid all the post-covid "chaparone policy" announcements wrt fights/shootings/incidents of that nature. After all, not everyone who goes here is going to want to ride Fury, yet they still gave more than enough info to suffice. Kudos to whoever authorized it, they're doing a fine job.

SteveWoA:

What, like RCT?!?

SteveWoA:
video somewhere of Gatekeeper being manufactured

That was a fun day...

Pretty sure there is a How It's Made special on them, for rides.

I think Clermont and CF and B&M just want to keep the blowback limited, there is no way it would be made at the Euro manufacturer in time, and I'm pretty sure no one else has jigs and the know-how in North America.

Completely agree. The transparency and the excellent explanation of everything being done was much appreciated. I’m not even a local or someone who has ridden Fury, and I haven’t even been to Carowinds since I was about 5, but I just think they really were pretty classy about the press release.

I have to wonder if there will be a formal state report. Part of me doubts it, as technically there was no accident. But, for a Mechanical Engineer, being able to read a formal investigative report is a great case study. For as sad as the Ohio State Fair accident was several years ago, reading the final report is extremely useful for anyone in the field of engineering.

Sharpel007:

I think Clermont and CF and B&M just want to keep the blowback limited, there is no way it would be made at the Euro manufacturer in time, and I'm pretty sure no one else has jigs and the know-how in North America.

Maybe Zamperla is making it for them.

Unpossible. They've never done that before. This must be their way of cutting costs.

Good Morning,

I'd like to pick up on my post from early on and possibly add some useful information. I'm not sure what he does, but SteveWoA may be able to add some info, or correct some items.

I'll leave out a good amount of details in order to keep this as readable as possible.

First, I want to explain what the park probably meant by the post, go into fatigue testing, related that to NDE (non destructive examination), and then tie it all together.

The Park's Response

The post by the park mentioned something called a 'weld line'. I imagine they're referring to what we refer to as the 'Fusion Line' (FL). The fusion line is where the weld metal (WM) and base material (BM) are joined. In general, the WM gets above the liquidus temperature, the BM does not (ehhehehehehhhh he said....).

Fatigue Testing

Why is this important? Many reasons. But, as some have proposed, this may be influenced by fatigue. Back in the day, I used to qualify and fabricate subsea welded structures and I really don't see this as a typical 'high fatigue' situation, but I'll run with it, to show a point.

Depending upon the application, us welding engineers would qualify and fabricate welds with unique testing. Sometimes (for at least subsea equipment), fatigue failure is a concern which needs to be evaluated. As a result, many test welds are made and fatigue tested. Typically, the tests would go one of two ways. First, the test would pass once a certain cycle count was met (were talking tens of millions) in which the strain gauges and pressure gauges have plateaued, and the test is completed/stopped. The other outcome is a failure at a certain number of cycles. Guess where the failures would typically be? They could be in the WM or BM, but mostly would be either near the cap's (last pass of the weld) toe or the root's (first pass of the weld) toe. This is right at the fusion line, or (once again) what the park is referring to as the 'weld line'.

Fatigue and SCF (Stress Concentration Factor)

How do we deal with this? Many ways, but i'll talk about reducing the SCF. This is the 'Stress Concentration Factor. If you draw stress flow lines at the weld interface, running towards the BM (uhhuhuhuhuh he said...) these stress lines bunch up near the toes of the welds (see above). These areas provide a notch where the SCF increases. So what can we do? Grind off the cap and grind out the root. This reduces the 'notch effect', and reduces the SCF. lower SCF increases fatigue life.

Now once again, I would not consider this as a 'high fatigue' situation, but maybe (big maybe) something was up with the toe of the weld (which is the fusion line). With my time in the industry, the toes can be susceptible if (big 'if) this is truly a fatigue issue. While grinding the weld flat is an option, it is impractical for the root to be ground, as it's inside the branch, and the acute angle of the cap would be difficult to deal with. Also, grinding off the weld's reinforcement isn't always an easy answer. Just like many things in engineering, gaining a 'pro' on one side can lead to a 'con' in the other. Grinding off weld reinforcement has its 'cons' and isn't always the correct solution.

CTOD Testing and Crack Propigation

Now let's walk backward for a bit. Prior to welding, another test that is used in high fatigue situations is a CTOD (Crack Tip Opening Displacement) test. This measures the way in which the WM, HAZ (Heat Affected Zone), or BM either direct forces into the material, or towards crack propagation. We want the material to absorb the force into the material and not go into crack propigation. So, the CTOD test involves a notch. At the end of the notch, a crack is initiated of a certain length and at a certain location (WM/HAZ/BM). keeping it simple, stress is applied to the jig, and calculations are made to see how well the tested material is at not allowing that crack to grow, under load.

NDE Requirements

Ok so who cares..... Well, we making welds, discontinuities happen and are expected. For high fatigue situations (once again, I'm talking a high amount of fatigue, and not necessarily a train every 90 seconds), these CTOD results can go into properly calculating NDE (non destructive evaluation) acceptance criteria. The better the results from the CTOD, the more 'loose' the NDE requirements can be written (typically). But, the reverse can also apply. If CTOD results are not great, the NDE acceptance criteria is typically tightened. Remember, we assume that discontinuities exist, just like that small pre-crack exists in the CTOD test. If the CTOD shows that the material directed the stress more towards crack propagation, instead of arresting the crack, the more we don't like having discontinuities in the weld. As a result, NDE acceptance criteria is tightened.

To clarify a point, a discontinuity is an imperfection which exists but meets NDE acceptance. A defect can be a larger discontinuity which is large enough to violate the NDE acceptance criteria and is rejected.

Now this is way overkill for a simple branch connection on a rollercoaster, so who cares? Well, as you are all aware, these welds undergo volumetric inspection, typically UT (ultrasonic) or RT (aka 'x-ray) at the point of manufacture. Given that it's typical to always have a certain amount of discontinuities in the WM (or even BM), it could be possible that a discontenuity such as LOF (lack of fusion) up against the sidewall, or undercut could become an issue during fatigue. LOF can occur near the FL; undercut will be at the FL.

But hold on..... does every weld undergo volumetric NDE? it's likely that B&M's fabricator would perform volumetric on all welds. I just don't remember if AWS (American Welding Society) D1.1 welding code requires volumetric NDE for ALL welds. It's been a while since I've cracked open that specific code book. SteveWoA may know?

To make y'all sleep better, any cracks found during NDE is typically an automatic failure, and the methods used are highly capable of finding cracks in the WM/HAZ/BM region.

Wrapping this all up....

So, it would be a possibility that a doscontenuity existed such as a small amount of LOF or undercut, which met acceptance criteria, but still existed. With these types of discontinuities typically being around the FL (fusion line), this is where the park called out the 'weld line' in the post. If the BM is susceptible to crack propagation, verified by CTOD testing, some material can be susceptible to crack growth (off of a previously existing discontinuity or defect) under fatigue loading. Put this all together, and a fatigue crack that formed after the ride's last NDE check, something big could happen.

Where to go from here

B&M, along with their fabricator, and CF are highly competent companies and I would image that they have hired outside help to look into the weld, base material, and crack face in order to find the reason. I don't want to list out companies, because I don't want 'CoasterBoy' to show up at someone's doorstep, but plenty of companies exist that specialize in these investigations.

They'll find it. It's a fascinating field.

-Ryan

I feel like this total clickbait image I found on Facebook following the post above it is a perfect encapsulation of what the internet has become.

https://flexsealproducts.com/#5

To say that the Internet has veered away from its potential to something very sad and the opposite of potential doesn't quite capture it.

Me: I’m sorry, wait… what? What happened? WHAT WAS IT?? Tell me! NOW!!!!!
Them: 😡

Lord Gonchar:

I feel like this total clickbait image I found on Facebook following the post above it is a perfect encapsulation of what the internet has become.

There were a bunch of stories published by various outlets that did't give any new information beyond the state saying that they're pretty sure the crack had been there a few days (which we already knew). Having looked at it from a different angle, I'm actually wondering if conceivably someone determined that it could safely run that way. Logical me says, well, if that support didn't need to be there, it wouldn't be there. But then I think about any loop on any B&M that's not supported from above, rotate the plane of that loop 80 degrees, and you have this track shape. Mind you, it probably wouldn't go that fast through the loop, and I assume that the width of the box track and perhaps thickness of the steel varies. As a layman, I'm still not convinced that it ran "dangerously."

Jeff:

Logical me says, well, if that support didn't need to be there, it wouldn't be there.

I thought the rule was that if the support was needed, it would already be there.

Jeff:

But then I think about any loop on any B&M that's not supported from above, rotate the plane of that loop 80 degrees, and you have this track shape. Mind you, it probably wouldn't go that fast through the loop, and I assume that the width of the box track and perhaps thickness of the steel varies.

Thinking about this, there is one other difference--how gravity acts on the train (and therefore the track).

For a vertical loop, gravity acts in the plane of the loop, so the loop structure itself potentially acts as a support. For an almost horizontal curve, more of the impact of gravitational force is met by that support.

I still suspect your conclusion is correct, that it was not "dangerous" during the time it was running. But also during that time the track was subject to additional and unanticipated/undesigned-for stresses, which can in turn contribute to (eventual) failures of the track structure.

You’re like me and many of us, I’m sure, who have spent time trying to justify this bizarre occurance. Or at least make sense of it. And we, as enthusiastic experts and (at the very least) amateur engineers, understand that in the end it wasn’t such a big deal and that the track held together and thank god nothing more came of it.
But if I had a nickel for every friend that caught the news and mentioned it to me, using words like “how on earth could it go that long without being noticed?” And sometimes adding “I doesn’t help me place a lot of confidence in the safety of those places”. So people are noticing and it’s not a good look.
I caught that same most recent coverage over the weekend and it turned out to be nothing new. Especially with no mention or justification as to the apparent delay in identifying a problem. Just the standard statements like “The park is working on repairs”.
This would be a tough one for the world of public relations. It’s really one of those situations where it’s absolutely necessary to be transparent but at the same time be careful not to say or admit too much. Take Clermont who clearly backed away as hard and fast as they could, even claiming non-involvement. But they are involved.
I also have to wonder about the rumored PR shakeup at Cedar Fair. According to observers Mr Helbig is no longer at his post, the reason why is nobody’s business, and Mr Clark had gone silent. Not to say the Charlotte event is behind any of it, but it’s an overlap that’s weirdly coincidental.