Serious accident on Xcelerator caputerd on Video

They will be lucky if they're allowed to reopen Xcelerator before the end of the year. California's ride inspection laws are so loosely defined and so far it's been a nightmare for the parks and ride manufacturers to deal with. On average a ride that is taken over by the state is closed for at least 6 months. Looking at the video I suspect that the state will come up with a whole list of required modifications.

The state has forced California's Great America to take apart the Invertigo after the incident there in August. In that case the ride operated as designed for a chain failure.

They will inspect the ride with their so-called experts and then we will wait months for a report to be released to the public and then the park will be required to make any modifications they order and then the ride will have to be reinspected and tested before it can reopen.

When the CHILLER wheel boggies failed, cause the Robin train to fall onto its track and crack the fiberglass train in 2006 the other Premier rides were closed. It was the reason I didn't get my first ever ride on Mr. Freeze at SFOT in 2006. :(

Okay, now that I am not sitting at my desk where I am supposed to be doing, you know, actual •work•...

<geek>
I'm looking at the video in a slightly different way from the rest of you. YouTube automatically encodes everything into H.264 so as to make it iPhone compatible, as well as into Flash for the regular YouTube player. An add-on that I am running on my computer (ClickToFlash) re-writes the YouTube player pages so as to request the H.264 version. With a little bit of extra effort, I was able to download that file, and now I am looking at it in QuickTime Player. This allows me to watch a larger image, and it allows me to watch one frame at a time.
</geek>

What I first noted was the "cloud" of debris at frames 156-174...that would be (dammit, QuickTime what's this 1/100 second crap? My numbers will be 'timecode' at 30 FPS...) 0;00;05;06-0;00;05;24. That debris appears to be small shards, and looks a lot like the description attached to the incident on Top Thrill Dragster a few years ago. Consider also, for the moment, that this debris appears to be moving rapidly backwards, and in fact impacts the camera at about frame 163 (0;00;05;14). That suggests to me that this is something not related to the train, but rather associated with a particular location along the track, as the train goes through this debris 'cloud'.

At this point, the rider on the right-hand side (our left) eats his lap bar. The fact that the man on the left does not suggests that this is not an inertial reaction from the train slowing suddenly, but perhaps his response to being impacted by flying shards of whatever that is.

The train continues hurtling down the track and starts up the hill to frame 244 (0;00;08;04) where another, larger shard of debris appears. The interesting thing about this is that from the background you can tell that the train has actually executed a roll maneuver at this point: in 40 frames (0;00;01;10) the train has rolled 90 degrees counter-clockwise, and suddenly debris enters the frame again. It is reasonable to assume that this debris came from the train, and has been traveling at the same speed as the train up the hill, coming to a stop at about the same place as the train, and falling backward as the train reverses direction. Because of the roll, the passenger section of the train is now entering an area previously occupied by the underside of the left-hand side of the train. This debris appears in frames 244-353 (0;00;08;04-0;00;11;23) and to me appears to be larger than the debris from the earlier cloud at the end of the launch track.

Now much has been made of the kid's seat coming loose at the end of the ride. In my analysis thus far, I have not seen any evidence of this. Frames 412-471 (0;00;13;22-0;00;15;21) show some excessive up and down movement of the camera, as evidenced by the motion of the dark mask at the upper left-hand corner of the screen. Within this section, at Frame 437 (0;00;14;17), there is some motion on the left-hand side of the screen that appears to be the right-hand seat jumping up in the air. I believe this to be an illusion caused by the video compression scheme employed. If you visit http://capital2.capital.edu/admin-staff/dalthoff/xcelerator/ you can see Frames 435-440 exported as PNG files from the original movie. You can see in Frame 437, the headrest on the right-hand seat is doubled, and the right-hand passenger has two heads, one above the other. Again, in Frame 439, the doubling appears again. Frame 437 is particularly dramatic as it appears that the car has split into two right down the middle. Again, I believe this is an illusion caused by crappy video quality. Notice that the armrests remain at a constant relative position to each other except on frames 437 and 439, and on those frames not only do the armrests appear to separate on the lead seat, but also the headrests on the other seats, and the camera on the second row appears to split into two *horizontally*.

Please remember that this video was captured, compressed, transmitted via WiFi, and presumably re-encoded from whatever compressed format cd•ride uses into MPEG-2. The MPEG-2 video was then ripped into some other intermediate format for posting to YouTube, and then converted by YouTube into H.264 and wrapped into both FLV and MP4 wrappers. It is known that even one recompression stage will introduce undesirable artifacts into the video, and this is video that has been recompressed at least four times, possibly more. I don't think the evidence presented by this video indicates a seat failure, particularly given that the seats return to their EXACT original position in Frame 440.

It is also worth noting that the rider received "lacerations". It's a big word meaning "cuts". We do not know the extent of injuries; we know that the riders were sent to the hospital for treatment, but we do not know how serious the injuries were. While this is a nasty and somewhat frightening incident, we do not have enough data from the video and from the news stories I have seen so far to know how bad things really were. Please try not to blow things too far out of proportion until you know the actual facts of the incident.

That said, I do know that an early discussion of this incident disappeared completely from WestCoaster, and we have seen that the video has been removed from YouTube, and from the NBC-LA site, where it was taken down and then put back up again. I have to think that Knott's attempts to prevent news of this incident from getting out, besides being ineffective, are also counter-productive and probably have led some people to believe this incident was more severe than it really was. Parks...all parks...need to understand that there are no secrets in this business anymore. Every person walking in the gate is essentially a journalist of sorts, worse yet a journalist probably with no formal training and no concept of fairness. If something happens, the word will get out, and the park that tries to control the flow of information will discover it has no control at all. It is the park that understands this and creates the flow of information, keeps it honest and keeps it coming, that will be able to control its own image in a time of crisis. Especially if that crisis is a relatively minor one, as this one appears to be.

--Dave Althoff, Jr.
(note: it took a while to write this. Last post before I started: TServo asking about the rope failure mode, and whether ropes are replaced periodically...that would be the last post on p3.)

Didn't TTD have a launch cable incident a few years ago. As I remember one rider had a cable splinter pierce his ear.

Dave, while I greatly respect your mechanical and technical knowledge, it is very evident that something happened with the boy's seat, as it is in an entirely different position than it started in. You can see very clearly that when the action occurs during the roll back that his seat is the only one that moves. His seat back is also (from looking at the headrest) positioned/turned about 20* I would guess after the large bump.

I am basing this analysis off of the video on the NBC site.

Also, further note that it seems to be ONLY the seat back that is affected, not the entire seat and mount, as I previously thought. Still, that seems very odd to me.

A few questions: Do they not check the cables for fraying on a regular basis so that this does not happen? Was this preventable through normal maintenance and inspection of the ride?

That kids seat totally moved. This is some serious stuff.

Watching the video also makes me think that there was some damage to the track and on the way back thats when the train got messed up.

RideMan said:
Please try not to blow things too far out of proportion until you know the actual facts of the incident....

....Especially if that crisis is a relatively minor one, as this one appears to be.

That's an interesting perspective, Dave. How are you measuring the significance of the incident? By the perceived injuries?

Regardless of how lucky it was that no one appears to have been seriously injured, a cable snapping on a launch coaster is a pretty significant incident to me. That kind of thing should never happen and if it does, there's no telling the impact it could have.

And even if it wasn't a cable, there was clearly something hitting the riders at 80 mph. I think that's pretty dangerous no matter how lucky it may have turned out to be this time.

Knowing nothing about the ride and its supports, I wonder if Dave could frame by frame

Check the backwards roll of the train down the tower. It could be total optical illusion

But I see cable above the riders heads as it drops back down. I dont know if its support cables or what

or just a optical thing.
Chuck

Dragster was still running this evening.

Roz

See, I'm in the minor incident camp at this point too.

Then again I thought the TTD incident was blown out of proportion too. I believe my take was "boo boos" (the thread still has to be around here somewhere)

I think this goes back to the "respect the rides" thing in Dave's signature. It's easy to forget that these are large pieces of machinery that, while extremely safe, aren't foolproof. Nothing is.

Now you've got me trying to figure out if it's the seat back, the headrest or the camera that's moving there. What I am noticing is that the steel frame doesn't appear to go anywhere; the movement is all apparently in the backrest and headrest, or possibly those are merely shaking and the whole camera is moving. Remember the camera has an extra-wide-angle lens on it which distorts the scene, so it is possible that we are seeming some camera motion here, I am not entirely certain, but that's what I am thinking.

--Dave Althoff, Jr.

I didn't realize these cables only where good for a year. How long to the cables for the shuttle coasters last? I assume longer, since the launch is not as strong.

http://ocresort.freedomblogging.com/2009/09/18/knotts-xcelerator-ri...two/18815/

The cable in question was last replaced in December.

“We were using the proper cables” recommended by the ride’s manufacturer, Blazey said. “They’re good for a year.”

Dave, if its some kind of distortion, then it is happening in a very well defined area of the video, which to me rules out that possibility. The seat back is very much in a different position than it started, and most definitely moves. I've watched the 5 seconds encompassing that moment several times, and I see nothing odd about the rest of the video, just that particular seat back.

What if the car ran over the cable while traveling in reverse? Wouldn't that cause the rear wheels of the car to bump up first, slightly changing the angle of the car and thus create the effect of the seat moving foward, towards the camera which we see in the video.

I'm actually with Dave I don't think the seat really moved. I watched the video over an over now. Knott's is next door to me and I've been on Xcelerator too many times to count. I don't see how this incident would cause the seat to dislodge.

Yeah, I disagree about this being a minor incident. To me, respecting the rides means don't be a fool who intentionally keeps the safety harness loose or who tries to stick a leg up in order to get a funny on-ride photo... stupid stuff like that.

A coaster throwing up its parts on a rider is not anything that should be expected and certainly not accepted. If things go a little bit differently and some of that debris catches the kid in the eye, does that change the circumstance to major? (I'm not being smart; I'm really asking what is the measurement for major/minor.)

RideMan said:
Now you've got me trying to figure out if it's the seat back, the headrest or the camera that's moving there. What I am noticing is that the steel frame doesn't appear to go anywhere; the movement is all apparently in the backrest and headrest, or possibly those are merely shaking and the whole camera is moving. Remember the camera has an extra-wide-angle lens on it which distorts the scene, so it is possible that we are seeming some camera motion here, I am not entirely certain, but that's what I am thinking.

--Dave Althoff, Jr.

I was thinking that the camera moved too. If I put my finger on my screen on the launch tower in the background at 4 seconds - leave my finger there to 14-seconds (in the NBC video) - the launch tower moves to the left. So I would assume that this is the whole camera being moved at some point.

Carrie M. said:
If things go a little bit differently and some of that debris catches the kid in the eye, does that change the circumstance to major? (I'm not being smart; I'm really asking what is the measurement for major/minor.)

I dunno.

I live by the mantra that stuff happens. People will get injured on amusement park rides...and do. Often it is freak occurance and sometimes it is very serious.

In this case the injuries at this point don't seem to be more than boo boos and we'll eventually find out why it happened. But in the end if stuff just happened and these guys walk away with boo boos - then it's a minor incident. Right now I have no reason to believe it's anything more.

I think looking at the kid's seat relative to the other seat shows it moved. Look at it also relative to the drop tower and the seat behind him. For the entire clip before the stopping "thud" in the middle, you can't see the entire "hole" in the headrest of the seat behind him. After the thud, it's quite visible, and the seat remains higher and/or more forward compared to the port-side seat. I don't think that's a compression or interlacing artifact.

I would agree that in the bigger picture of headlines, this was a minor incident. But what it does do is raise a lot of serious questions about the safety systems of these rides. Ultimately, I suspect that's where a lot of the important discussion has to take place for the people who own them.