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.

 

[dik]

Notes revised:

-THROUGH BOLTS FOR HSS CONNECTIONS SHALL CONFORM TO ASTM [F3125, GRADE A325 | A307 GRADE B] AND SHALL BE SECURE. TORQUE TO 28.8N-M (100FT-LBS) (DO NOT CRUSH HSS WALL). SECURED USING LOCTITE 263 (RED) THREAD LOCKER OR THE THREADS SHALL BE PEENED TO PREVENT LOOSENING.

The notes are always in a state of transition... fixed as problems develop.

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

 

[TugboatEng]

The most important distinction for red Loctites is the bolt diameter. Larger bolts have greater clearances which don't promote the anaerobic conditions required to cure the Loctite.

 

[Cool_Controls]

So did the ride manufacturer provide a procedure for prox switch adjustment/replacement?

 

[byrdj]

not sure if someone else hasn't made this comment...
after watching above, the resolution of the safety switch versus the final position it was verifying. such a small change resulting in large differance in closure gap.

 

[BrianPetersen]

Loctite is not the issue here. Safety switches should never be mounted in the manner shown. Ultimately, it is not possible for the machine designer to completely prevent intentional tampering, though.

 

[LionelHutz]

Agreed, use of Loctite is irrelevant to the whole discussion. The intent when designing this ride might have been good, but in my opinion the implementation is terrible. Loctite won't fix this crappy implementation.

We've seen the pictures of the single proximity switch that determines the restraint is lowered enough. Has anyone seen details on the latching system and the safeties on it?

 

[dik]

Can you elaborate?

Also... if the set screws were of a sufficient grade, the connection should be slip critical and loosening should not be an issue. If the fasteners were behind a screw on 'cover plate' they could still be 'messed with'.

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

 

[BrianPetersen]

The bracket should not be adjustable by enough for the safety function to matter. Shouldn't have slotted holes. It should have two holes in the right spot, not adjustable. I don't buy the commissioning argument. Even if calibration and field adjustment were necessary, they should accommodate only the minimum necessary amount of adjustment ... not as much adjustment as possible! Figure out where the holes needed to be during commissioning then replace the adjustable brackets with fixed brackets having the holes in the right spot. Or design it right in the first place.

EN 1088 (interlocking devices associated with guards) requires protection against tampering, e.g. use of tamper-resistant fasteners ... although I would have to say, I have never seen this applied in reality. Equipment destined for use by (relatively) unqualified personnel would be a prime application for that, though ...

https://www.schmersalusa.com/uploads/media/Tampering.pdf

 

[BrianPetersen]

I should add that the switch they are using is not a "single proximity switch". It is a Pilz PSEN coded safety switch. There is no issue with the switch itself - it contains protection against electrical faults and it cannot be circumvented with simple objects (coin, washer, etc) the way a "proximity switch" can. The switch is fine. The way it's mounted is wrong.

 

[dik]

Thanks, Brian.

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

 

[TugboatEng]

Are they saying the switch was adjusted to accommodate the larger rider? I find that doubtful. If it was misadjusted earlier what are the odds that the large rider found that specific seat. Or were there many seats misadjusted?

 

[Sym P. le]

Earlier reports indicated that several seats were adjusted to accommodate larger patrons and those larger patrons were directed to those seats.

 

[dik]

...new stuff.

https://www.dailymail.co.uk/news/ar...een-died-blunt-trauma-Florida-ride-death.html

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

 

[LittleInch]

A pretty good summary there, but the last sentence is a joke. This ride was, IMHO, a disastor waiting to happen.

Tilting forward wasn't mentioned but critically removes a level of safety by changing the force path from one going through the seat to requiring the harness to actually hold the person in. Then no second restraint to prevent submarining and then the "manual" adjustment to accommodate larger riders but still activate the position sensor to say it was all good all add up.

It then took a rather exceptionally large individual to breach the boundaries, but "accident"?? No way.

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

 

[IRstuff]

This was pretty much a true engineering failure; someone failed to do a proper FMECA.

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

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[analogkid2digitalman]

The ride is being taken down:

https://www.cnn.com/2022/10/06/us/tyre-sampson-orlando-free-fall/index.html

-AK2DM

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It's the questions that drive us"
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[dik]

I'm surprised they didn't wait until any court activity was completed... it's a bit of an admission of fault of some kind.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[SwinnyGG]

Not surprising at all. The 'following the wishes of the family and the community' and 'scholarship in his name' bits are going to play well during the civil suit to come.

 

[Roga50]

Looks like we almost had a repeat:

Link

News Article: Link