Guest taken to hospital after metal object falls off TTD

Yep. Xcelerator never closed, is older, operates at a year round park and is operated by Cedar Fair. This wasn't design related IMO. I believe they know it was some level of maintenance failure, and knew pretty quickly.

I’m not proud of the 3rd shift maintenance team for not ensuring this part was screwed on correctly. Some of the trains were making a weird “clanking” sound coming in through the brake run weeks prior to the incident. I point the finger at them. Their main job is to inspect each and every part of every train every night before signing off that it’s good to run in the morning.

That's an awful allegation to make in the absence of evidence.

CedarPoint150 said:

I’m not proud of the 3rd shift maintenance team for not ensuring this part was screwed on correctly. Some of the trains were making a weird “clanking” sound coming in through the brake run weeks prior to the incident. I point the finger at them. Their main job is to inspect each and every part of every train every night before signing off that it’s good to run in the morning.

2 posts to your name and you are slandering the third shift maintenance team? Yes they are supposed to preform regular inspections, but im not sure how you expect them to catch a (from my assumption) metal fatiqued bolt, especially on a non structure critcal part. Also if there was "clanking" as you say, can you with 100% certainty confirm it was specifically coming from the green train? If so why didnt you feel compelled to report it to park operations? Or the ride host? Surely if it was making an abnormal noise for "weeks" as you say, im sure someone would have said something.

CedarPoint150 said:

I’m not proud of the 3rd shift maintenance team for not ensuring this part was screwed on correctly. Some of the trains were making a weird “clanking” sound coming in through the brake run weeks prior to the incident. I point the finger at them. Their main job is to inspect each and every part of every train every night before signing off that it’s good to run in the morning.

You sure do sound like other people I know that does not check the oil in their own car and blame the car and manufacturer when the car breaks down. A quick study on metal and metal fatigue would be in order as well as the manufacturer recommendation on bolt strength and torque pressure and any needed documentation. It is also on the manufacturer to place a P.M. schedule on each item and how the p.m. should be preformed and documented. The sad part is that a person was injured, but there is a lot into the investigation as to why the failure happened. It could be the problem with bolt manufacturer or one or more of many circumstances. To put blame on one group of individuals like "third shift employees" is beyond absurd and not justified. Please stop the bullying and allow the process of discovery on the CP team and legal team to continue this investigation. We hope for quick closure to this event and that the victim has no life long injuries.

Naw, he’s just a pissed off, second shift maintenance man.

I’m allowed to have my own justifications. I hope it wasn’t an over sight on maintenance inspections and I guess we will never know for sure… but that seems like the most logical explanation to me. I love Cedar Point so I hope that’s not the case and it was a random freak accident that couldn’t have been prevented. But yes overall I hope the investigation is closed soon, the woman heals and the ride is able to reopen safely next year.

CedarPoint150 said:

I’m allowed to have my own justifications. I hope it wasn’t an over sight on maintenance inspections and I guess we will never know for sure… but that seems like the most logical explanation to me. I love Cedar Point so I hope that’s not the case and it was a random freak accident that couldn’t have been prevented. But yes overall I hope the investigation is closed soon, the woman heals and the ride is able to reopen safely next year.

Wow thats quite a different tune than your previous posts. By the way A+ job sidestepping your way past everything I said in my previous reply.

Ssssshh. Relax. The noise I heard was reported. Whether that noise had anything to do with the incident I am not sure. I’m not “slandering” 3rd shift all I’m saying is that I feel if anyone were to be able to discover the fatigued or faulty piece and replace it before falling off it would have been them as they are the main people in charge of inspecting the trains. If the piece was firmly connected the night before Sunday and it was indeed a faulty bolt that decided to give way during the middle of the day then there would have been no way to discover that unless the entire train was taken apart. Which apparently may need to actually have to happen routinely now in order to prevent something like this happening again. Who knows. The whole situation sucks big time.

What you are doing is the literal definition of slander, genius.

Seriously, just stop. You have no idea what you're talking about.

Please humor me and tell me how you know what 3rd shift maintenance responsiblities may or may not be. Because the kind of "inspection" you are calling for is a undertaking performed during off-season maintenance. A quick visual inspection of structure and train, along with fixing issues reported throughout the day, along with some preventative is really, to my understanding, what happens during 3rd shift. None of this would have caught metal fatique unless it was blatantly obvious or showing other signs. As someone who has worked at cedar point (albeit not in ride maintenance-but have talked with lots of ride mechanics in passing while there) and someone who deals in repair of equipment on a daily basis in my current job, i can tell you; you can thoroughly inspect as much as you want- things are still going to happen that are near impossible to catch.

Regarding design flaw:

For a moment, let's assume that Dragster has some design flaw that has a one in a million chance of a metal plate being thrown from the ride and hitting someone in the queue. A very crude probability estimate would result in a 33% chance of the incident happening within the first 20 years. In other words, if there were a design flaw that had a very low probability of happening, its fully reasonable to expect that the ride could operate for 20 years without incident.

I think at the end of the day you would have to chalk it up to "**** happens," because the odds of the failure are probably astronomically low. There's certainly some question about proximity of the ride to humans, but even then, things tend to move in the direction they're going. That this deflected off at such an angle seems even more unlikely, presumably hitting the track in just such a way to enter the queue.

This may have nothing to do with the incident.

When you fasten a part with a bolt (or in this case a capscrew) the bolt functions by *stretching*. So you thread the bolt into the parts (and in the case of a bolt, spin the nut onto the back) until it bottoms out, then tighten the bolt to a specified torque. Doing that actually stretches the bolt, which responds a bit like a spring by trying to return to its original length. It's that tension which keeps the bolt in place.

There are two ways that a bolt will lose torque. The first is if the bolt is loose enough that it can rotate, which obviously will allow the bolt to back out. Vibration can do this, and there are a variety of safety methods to prevent it, including thread locking material, safety wires, and various types of stop nuts. The other thing that can happen is that if the part is subject to impact loading, it can actually stretch the bolt, possibly past its yield point; that is, the point where it will not spring back to its original length. That's more likely to happen if the bolt isn't torqued properly to begin with (because if it were torqued properly, there wouldn't be any impact loading on the joint). That's what happened at Michigan's Adventure on their Chaos. The maintenance crews thought that since there was no change in the witness markings, clearly the bolts had not moved and were still tight. In fact they were loosening up until at least one bolt failed, causing the rest of the bolts to shear at once, causing the ride center to fall off of its bearing.

Now, the part we're talking about on Dragster should be subject to almost no loading whatsoever. It's not supposed to ever come into contact with anything, and if the capscrews are torqued properly (perhaps even secured with thread locker) they really should not be subject to anything that would cause them to come loose or to become at all fatigued. With that in mind, another possible conclusion can quickly be reached: that there was another failure, and that the bolts in this part failed (sheared off) as a result of the incident, not as the proximate cause of it.

The only problem with that theory is that the only thing I can think of close enough to that plate to strike it would be one of the switches...which appear to be constructed in such a way that striking one would cause the switch to fail catastrophically while doing little or no damage to a (comparatively) rather large hunk of steel.

Please bear in mind that I know nothing beyond what has been previously revealed. I'm also involved in enough other pursuits at the moment that I'm not exactly digging for details right now, either. (Anybody know a good QuickTime Pro replacement for MacOS X,XV or later?)

--Dave Althoff, Jr.

djDaemon said:

What you are doing is the literal definition of slander, genius.

Seriously, just stop. You have no idea what you're talking about.

No, it's not. If anything, it would be libel.

Slander, by definition, is defamation conveyed orally.

Libel is defamation conveyed in written form.

Fair point.

The clanking noise I heard is in this video at 5 mins 25 seconds as the train enters the brake run.

But that's the purple train, unless you are implying that each of the trains have this issue (which would be even more incredible than what already happened).

Or perhaps you are suggesting it's a structural issue; in which case each of the trains would be showing some type of damage to the exact same area. If that were the case, I would think a simple visual inspection of the trains' underbellies would make something stand out. If a part of each of the trains were coming into contact with the structure on every single launch since when this video was taken (late September) I can't fathom something not sticking out.

Then again, this whole situation is bizarre, so who knows?

I don't know. If I just watched that video without any suggestion, I would just chalk up those noises to the sounds Dragster makes.

I am in agreeance with Rideman. If the bolts were inspected by (let's say third shift) maintenance. (clears throat...) every day because they do their job better than anyone! If the bolts are to be maintained at a certain torque, and checked every day. It is possible that the bolts may become over torqued over time and the bolt may break. This is what I though when I first heard of the report that the boken bolts were still in the plate. Please correct me if I am not correct in my facts or thinking!

Tourqing a bolt requires a tool called a torque wrench. It is a specialized instrument that sets the bolt to a proper torque. For a torque check you would put said wrench on bolt (set to whatever the spec may be) if it clicks or otherwise signals the bolt is at the proper tourque, no further tightening happens. There is low probability the hardware would become "over torqued" specifically over a period of time