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.

 

[LittleInch]

I don't know if its ll the houses but recent ones also included space for a future lift for when you can't climb the stairs any more....

But seriously, the point is where do you stop in terms of percentile at the top and bottom to not compromise safety for the middle 95%.

Maybe the designers hadn't really thought this through given the growing size of the population in most cultures, especially that of the USA.

So a few XL and XXL seats and some XXS ones as well...

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

 

[cranky108]

900mm I believe is about 35.5 in, which aligns with our 36 in doors. But not all interior doors are that width here. I believe 36 in is just the front and back door, so one can get a couch in the door.
I think the smallest doors are 24 in (~609mm)for small closets, but no one need to actually enter them.

What would happen, is an XXS person, wanting to be next to there friend, will want to be in a XXL seat.
So for a ride operator, we would need to assume some percentage of seats can not be used on any one ride time. So the whole passenger capacity will be decreased.

 

[Alistair_Heaton]

The aircraft seat and floor design load is regularly getting debated.

The FAA did a load of airport testing. Of course the salad dodgers refused to participate. And even then they have refused to release the data, and a lot of us suspect that's because the current standard pax weights are way way to low.

 

[Alistair_Heaton]

Just looked it up ours have to be 900mm on ground floor on new builds. But they can apply for a waver with certain property types.

 

[enginesrus]

I've seen some very dangerous problems with rides at the various fairs. It's a shame that happened, no excuse for any kid to get hurt on a supposed fun ride.

 

[IRstuff]

I would almost never trust a traveling fair's equipment; there's zero guarantee that they've been properly maintained, at all times. Permanent parks have to have repeat customers and there's more scrutiny on them

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

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[LittleInch]

This is interesting

https://www.cdc.gov/nchs/data/series/sr_03/sr03-046-508.pdf

Go to table 5 for men in kg.

So to cover 75% of the population the weight increases from the 50% from 90kg to 104 kg (200lbs to 230 lbs)
95% is 140 / 310lbs

So this kind of explains the weight limit used by the ride designers, but seems a little low.

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

 

[dik]

I thought the 275lb design weight was good... the kid weighed 375lb. Not even close. I think it is a bit silly to design for such a huge load; it's better to exclude this weight class. In other words, why stop at 375lbs? Why not 500lbs? Someone should have prevented the kid from accessing the equipment. I don't know who modified the 'harness' to allow 'overspec'd' people to use it.

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]

I don't know who modified the 'harness' to allow 'overspec'd' people to use it.

I suspect that's where all the energy is going now to find a culprit or company to sue.

The practical difficulty is how to police a weight limit. Height doesn't work as you can be 6'6" and built like a bean pole.
I quite like chest size myself, but again very difficult to measure on a fast moving ride queue.
Or perhaps a human version of the cage they use to stop you bringing on oversize cabin bags??

But if the weight limit was 275 or 285 lbs, that would seem to exclude 8-10% of the US population of 20-30 yr olds according to that report. That's quite a lot so then it makes sense to have say 5% of the seats specially made for up to 170kg / 385 lbs??

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

 

[dik]

I would have thought that the 275lb limit would be excluded less than 5%... out of touch, I guess. If the restraint is well designed, there could be a large cost to design restraints for the 5%; this should be passed on to the 5%, and not have others pay for it. I don't see that a weight 'go or no-go' would be difficult if someone really wanted to impliment this restriction. This kid's death was a direct result of someone allowing him on the ride in the first place.

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

 

[thebard3]

So if we include provision for 5%, 1 in 20 doesn't seem so bad. Also, the more one fits inside the bell-curve, the better they would also fit in a common seat. If you have to accommodate the 1%, that probably requires different equipment. You shouldn't really expect someone in the bottom and the top 1% to fit in the same seat. I'm not sure how many seats on this ride total. Assuming there was a single seat designed for that, then the ride capacity is reduced if none are present. Also, do you provide a separate queue as they would be limited by the number of seats available for them? At some point things become impractical. Imagine if regulators required handicapped accessibility for amusement rides. It's not impossible.

Brad Waybright

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

 

[spsalso]

"Stand here."
"Press this button when you're ready to be weighed. If the alarm goes off, you can't ride."
"Yes, you can try it again."
"Until I get irritated."


spsalso

 

[LittleInch]

Dik, I think you were right before and that the real reason is that someone modified one or two seats to accommodate larger individuals.

The poor attendants just did what they were shown, I.e. put the big guy or gal in that seat.

The bard, there were 30 seats I think so if 1 or 2 were specifically for larger than "average" customers I think that would work fine.

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

 

[dik]

I've found that if you make enough guesses, you get the odd one right. Even the earlier clip of someone 'higher up' (I assume he was management He was the director of marketting.) noted that there was a height restriction, but stated there was no weight limitiation.

https://www.clickorlando.com/news/l...es-to-investigate-teens-death/?outputType=amp

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

 

[Martin72]

This video is showing a lot of missing links in the accident report

https://youtu.be/2ZeDeG2a9WE

 

[dik]

A really good link and video... The adjustability of the swithches is I think necessary for fabrication purposes... maybe a use for Loktite Red 271... I think the fault is with whoever adjusted it, not with who manufactured it.

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]

Interesting that you added the number to the Loctite spec. Most people only know Loctite by it's color which is not representative of the application. My experience is that the colloquial Loctite "red" is 262.

 

[dik]

correct Tugboat... my error... I generally just use Red... I generally use 263 if I spec a number... pulled the number of the web, without confirming it. Thanks.

https://www.loctiteproducts.com/en/...cts/specialty/loctite_threadlockerred271.html

From my notes:

-ALL FASTENERS, SUPPORTING MECHANICAL EQUIPMENT, WHERE THE NUTS ARE LOADED IN TENSION ARE TO BE SECURED USING LOCTITE 263 (RED) THREAD LOCKER OR THE THREADS SHALL BE PEENED TO PREVENT LOOSENING.
-EOR TO CONFIRM BOLTS FOR ‘SLIDING’ CONNECTIONS MAY CONFORM TO ASTM A307, GRADE B, AND SHALL BE FINGER TIGHT. TORQUE TO 2.3N-M (20IN-LBS). PROVIDE SLOTTED CONNECTIONS AS REQ’D.
-THROUGH BOLTS FOR HSS CONNECTIONS SHALL CONFORM TO ASTM F3125, GRADE A325, AND SHALL BE SECURE. TORQUE TO 28.8N-M (100FT-LBS) (DO NOT CRUSH HSS WALL).
-DIAMETER AND QUANTITY AS SHOWN. SECURE BY PEENING, OR LOCTITE 263 (RED) THREAD LOCKER.


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]

I was trying to commend you for using the actual product number instead of the color. There are quite a few."red" Loctites.

 

[dik]

Thanks Tug... didn't know that; I've always spec'd the 263. I didn't know there was 262 or 271... I usually spec a number and didn't recall which one... so did a quick internet search and came up with 271. I often encounter connections for mech equipment where the equipment is 'hung' and the fasteners are in tension (includes hanging rods) and sliding connections... I always stipulate that they be 'glued'. I've revised my sliding connection to include A307, just now...

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