Amusement Park ride tragedy 9

[Brian Malone]

https://youtu.be/ozhnXp9OWEk

A 14 year old was killed when he slipped out of the restraint harness on this free drop ride. He was a very large teen - more than 6 ft tall and about 340 lbs. From what I have seen in other stories, he exceeded the ride manufacturer's stated weight limit.

This looks like it may be a case of additive errors leading to a bad outcome:
1. It appears the over- shoulder restraint bar/harness did not have an interlock for ensuring proper latching before allowing the ride to function. Or if an interlock system exists, the interock did not work.
2. Ride operators did not check all rider's harnesses status prior to starting the ride.
3. The ride operator appears to have discounted the kid questioning why there was not any 'click'
4. The ride operator(s) either ignored the allowable weight limit for riders or were not trained to enforce the limit. Chances are there may not be a scale in the entry queue and the operators have to use a visual estimation of rider's weight.
5. Apparently the ride does not have seatbelts as a redundant safety measure. There appeared to be some questioning about a seatbelt.
6. The young man may have become anxious as the ride rose and he moved toward the front edge of the seat or pushed up on the restraint/harness in an attempt to ease his anxiety and thus changed his body angle and CG relationship, thus moving out of the cup of the seat. Anxious or not, by the very motion of the ride his body would react against the over- shoulder restraint bar/harness during the drop and if it has a rotation axis to ease entry and it was not locked it would be free to rotate and reorient the young man's body angle in relationship to the seat. Upon deceleration, the kid just slid out under the restraint.

The details are still unckear but this ride is a new construction so it will be interesting to see the failure report.

 

[IRstuff]

Sassenachs is used in relation to the English by the Scottish and is used in a more of an offensive manner

One term I've actually heard used; it was used the Netflix series "Outlander" but as a term of endearment for the main character by her Scottish lover

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Alistair_Heaton]

I really couldn't see it being used as a term of endearment but there we go Language usage over the years changes.

There is a whole other side of phrases in south west Scotland which revolve around religion and the Irish troubles and if you support Rangers or Celtic. Thankfully being an east coast child that played rugby I wasn't exposed to them or got into the habit of using them.

By the way Salad dodger is also a UK army term. And I had it yelled at me more than a few times

 

[LittleInch]

Getting this back on track a bit....

I had a trawl around some videos from when they were building this and none of the seats looked any different to any other.

Does make you wonder if in order to accommodate the larger riders they adjusted the point at which the over the shoulder harness was considered to be locked? Or somehow extended the seat out a bit to give more room between the back and the upstand.

The fact they took the seat away though still seems suspicious to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Roga50]

New update from news in South Florida:

https://www.local10.com/news/florid...re-adjusted-on-ride-where-teen-fell-to-death/

Here is the report:

https://www.dropbox.com/sh/7oss0c7w...ilure+Analysis+Field+Investigation+Report.pdf

All part of this public dropbox published by Florida:

https://www.dropbox.com/sh/7oss0c7w8d2i3h1/AAAeOaAs6_wBQgp_jZO34ilha?dl=0

Smoking gun: Someone adjusted the position of the proximity sensor for two of the seats (including the one the victim was in) to allow for a larger opening--almost 7 inches vs 3. They also found evidence it was readjusted after the original installation, by way of bolt marks on the bracket. Now... Who did this?

 

[LittleInch]

To be honest, even that "normal" gap looks rather scary to me but the extended one is unreal.

How no one fell out before now is actually puzzling but may be they forced it down beyond the max opening.

Hence why a lot of rides have a locking belt as well to force the harness down to an agreed minimum space.

I think belts may become mandatory. Or maybe should is the right word. Otherwise this will happen again somewhere else.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Cool_Controls]

It would be interesting to know if the manufacturer specifies a go/no-go range for setting the restraint opening. Their must be, proximity switches will fail, I'm a bit suprised two proxs weren't used.

 

[IRstuff]

Nevertheless, there's no way the victim, at 300 lb, would have been able to fit through a 7-inch gap. Additionally, the few rides of that type that I've been on had a restraint strap that went between my legs, so if nothing else, the strap would have kept me from coming out of the seat.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Roga50]

One thing they mentioned in the report is that they tested the seat with someone of similar size to the victim and the foam of the seat compressed an additional amount. They said their testing showed the gap could have been as high as 10 inches...

Also up above there was some speculation about the forces involved. In the report they say testing with an accelerometer showed that the ride pulled 4G's...

 

[spsalso]

If this quite large kid slipped through the "expanded" seat restraint, wouldn't a lot of not-large kids slip through the non-expanded seat restraint?

I note that the report did not examine this question.



spsalso

 

[LittleInch]

It all depends on how tight you pull down the shoulder harness. The prox switches are really there to show the max possible gap which will depend on body size. That's where the operators come in to positively force the harness down plus most people will want to fee secure so will pull down hard to lock themselves in.

Basically it looks like someone adjusted the max opening of the harness to allow people bigger than the seat was designed for. The whole seat should have been bigger. Now who and if the manufacturers were ever asked or advised or even told is not clear or if instead poor Joe the ride maintenance man will cop it for some vague verbal direction to "adjust a couple of the seats will you to let the big guys ride".

But the lack of secondary restraint / physical max opening strap is a major secondary failure. IMHO.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Cool_Controls]

While the the requirements for a class 5 restraint system may seem robust on paper, this implementation would seem to be very brittle and indicate the need for additional requirements. Perhaps not allowing the locking mechanism to engage outside its specified range. Granted any system can be circumvented with enough effort, but at least make that amount of effort moderate to high. The ride appeared to use a coded saftey switch and not your run of the mill prox switch, but at the end of the day it meant that it could be defeated by a 75cent Allen wrench instead of a 10cent washer and some electrical tape.

 

[LionelHutz]

This report is rather surprising to me. It sounds like the lock is a ratchet that will lock in a wide range of positions and the only safety was the single proximity switch that determined the restraint was down far enough.

I see these obvious failures that don't make this design class 5;
- The safety system using a single proximity switch to determine if each seat is safe.
- The restraint latches with the harness too far open combined with nothing to ensure the latch was locked on each seat harness.
- The harness to seat having a gap.

There might be something that indicates the latch is closed, but that might be an overall for all the ratchets on or off.

I suspect the class 5 design was claimed by the ride having 2 ratchets on the restraint, one on each side. What would be interesting to see is only latch one and see how far the restraint could open under load.

Possibly, this configuration was used on other drop towers and has historically proven to be safe without dropping anyone, but the seats tipping forward wa added to the design without making the restraint system and safety indicators even more robust.

The posts about poor engineering on the ride seem to be true. Surely, a mechanical restraint like that can be built so it wouldn't latch at all until closed enough. Then, multiple sensors could surely be used to indicate that both latches were actually latched. For a ratchet, which any design most likely employ, the last step before running it is dropping another locking restraint behind the ratchet so the ratchet pawl can't move at all.

 

[thebard3]

I have seen similar rides with a seatbelt restraint between the parts described as 'harness' and 'seat horn'. That seems simple and much safer design.

Brad Waybright

The more you know, the more you know you don't know.

 

[LionelHutz]

The problem with a belt is that a rider could undo it themselves, which isn't something I'd want to have happening on a ride like this. That would mean the restraint has to be designed to still work even without the belt, which then eliminates the need for a belt.

Another possibly only perceived problem with a safety belt is that operators have to reach in between someone's legs to clip it for anyone who can't do it up themselves.

 

[Alistair_Heaton]

i can't see anything normal specs being design for that size of body mass.

Its way outside certification for car seats never mind aircraft.

A 14 year old that mass shouldn't be technically be allowed to sit on a bus.

 

[cranky108]

Are you saying someone that size would have to walk everywhere they went? Who else have I heard that about?
So much for the carts in Walmart.

 

[dik]

Exercise would do him good?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[Alistair_Heaton]

What are we meant to do, design everything for 150kg person to use because they do exist?

 

[cranky108]

Similar issue for very tall people. Do they build extra tall doors for them? I think not, unless they pay extra.
Same for wheelchairs in homes. But almost every business must accommodate them.
Sort of like the rest of society, be normal, or pay extra.

 

[Alistair_Heaton]

the point for me is by busting the design limits they are putting people that are inside the limits at risk.

But your in for a load of legal issues if you point out that they can't because they exceed the design limits. If you do that you are discriminating against them.

Oh and this side of the pond I think new build house do need 900mm doors for wheelchairs and a few other things but don't know them apart from the door width.