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Amusement Park ride tragedy
9

Amusement Park ride tragedy

Amusement Park ride tragedy

(OP)
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.

RE: Amusement Park ride tragedy

I can imagine a relatively junior employee staffing the entry not wishing to get into an argument with a customer or their parents about their weight. As for not-checked harnesses...that will be hot water for everyone involved.

RE: Amusement Park ride tragedy

I've been on rides like this anit looks like the primary restraint in the over the shoulder hinged pull down which normally has to get to a certain position before the ride will go. This is such that there isn't enough gap between the bottom of the restraint and the upstand between you legs. You also tend to sit down into the seat with your legs at a certain angle up.

One's I've been on also had a belt type clip which went from the middle of the crotch to the hinged down restraint to prevent the restraint lifting if accidentally released and also give you back up to prevent submarining.

Looks like this seat had that extra belt, but on the side?

This is what it looks like empty.



I've also seen a blurry shot of the person on the ride and the restraint doesn't look locked in the down position to me. Basically his thighs were too big to allow the harness to go down to the same level as the others.

I've seen ride attendants bouncing up and down on them in the past to get them to click, nearly crushing the larger person in the seat so that they could get the green light.

I do feel for the kids being put in positions of doing this hundreds of times a day and having arguments with someone who is just too big for the seat, or marginally so. But the safety features on the ride shouldn't allow it to go unless locked down sufficiently. Maybe they need a couple of extra large seats on these rides to prevent this, but then you don't want a skinny person in them either....

If you watch this video of a previous ride - go to about 8:30 and you discover the seat TILTS FORWARD at the top! Looking a the person next to the person filming you can't see where the belt is, but it doesn't look the best fit of a "normal" sized person. https://www.youtube.com/watch?v=Yqyr0QuBjXQ

Wouldn't be surprised if it comes out that there have been a few near misses before.

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

RE: Amusement Park ride tragedy

In Florida at permanent amusement parks no state inspections are required Link although I doubt the state employees anybody that would know what they are looking at.

RE: Amusement Park ride tragedy

When you go back to this horrific incident https://www.eng-tips.com/viewthread.cfm?qid=437095

You find that the regulation of rides is rather haphazard. This is a comparison of states https://ridesdatabase.org/wp-content/uploads/2019/...

FL is actually not that bad - but note that only 9 states require operators to be >18 and FL isn't one of them.

This organisation spells it out really well https://ridesdatabase.org/saferparks/regulations/

It was that discovery not mentioned on the news channels that the seats tip forward at the top is truly one of the swiss cheese holes as it puts the force much more on the restraint than literally the seat of your pants.

I've been on one or two of these drop fall rides, but nothing as tall as that one and the force after your 2 or more seconds of "free fall" is really significant. I could easily believe 2G.

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

RE: Amusement Park ride tragedy

I understand the inspection issue, as there likely are no people at the state level that are qualified at every ride. And the exception for permanent rides is that in many cases when rides are taken apart and moved, the reassembly allows for the assembly person to take short cuts, like not installing more than half the bolts.
But that said, the insurance company should require an inspection by a qualified person, similar to boiler inspectors.
In some rides, the restraint bar is common for several riders, and in that case maybe a common scale can be used, but in this case it sounds like a single person scale should be available.

When I was taking my daughter to the fair, I would notice empty bolt holes, and I would see seats taped off and marked as bad. This was most concerning as a parent.

RE: Amusement Park ride tragedy

(OP)
Wow - the seats tilt forward for the drop! Obviously this really increses the 'falling' sensation and would be a plus for someone properly restrained but for a rider not locked this would reduce the restraining force provided by the cup of the seat. As others have pointed out - the ride operators are often older teens or near-twenties and working in an environment that is noisy, repetitious, distracting and fraught with pressure to maximize throughput while minimizing conflict with riders - this tragedy has probably been a near miss on many occasions. The engineering challenges of the over- shoulder restraint system is challenging:
1. Accommodation of many body shapes and sizes
2. Restraint force sufficient for a very wide range of potential load cases but not so high to cause injury to the rider
3. The lock/ latch indicator must discern a proper latch condition even in a condition of possible 'spring back' of the restraint against the rider
4. The latch must not be prone to jamming to prevent ease of unlatching
5. Latch mechanism preferably would facilitate efficient ride throughput
6. Latch mechanism preferably would require minimal effort by the ride operator
7. Latch lock/ indicator system would /should be able to survive thousands of make/break cycles

The mechanical challenges are daunting, then throw in the human interaction and the true scope of the design and operation of these amusements is evident. Having a seatbelt definitely would be a major mitigation for much of the inherent risk.

RE: Amusement Park ride tragedy

Apparently he was refused a ride on several other rides that day due to his size, but this ride let him on when it doesn't have any other straps or harnesses other than the pull down shoulder ones.

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

RE: Amusement Park ride tragedy

I find it hard to believe the seat tips forward enough to dump someone out at 400' above the ground and the only safety is some kind of locking mechanism at the upper pivot of the over the shoulder restraint. I wouldn't want anything to do with such a design.

RE: Amusement Park ride tragedy

It's absolutely astonishing that no testing exposed this design flaw. I question whether these over the shoulder systems were even intended for use in this orientation.

RE: Amusement Park ride tragedy

The design appears to work for typical "kids". This kid was a lot bigger. But that would mean he filled the restraint more than typical kids. And that should have meant he would have less chance of falling out.

So it appears that the problem isn't with "over the shoulder systems". It looks more like failure in the latching and interlocks:

If the latch latches, then the shoulder restraint will keep a larger person in.

If the latch does not latch, then an interlock will not allow the ride to function. Once the failure to latch is fixed, the interlock allows the ride to function.

There's likely more to it, but that looks like the main concept.



spsalso

RE: Amusement Park ride tragedy

(OP)
The FMEA used by the amusement ride fabrication company must be somewhat ad hoc and mitigation for failure of the restraint systems was low on the list of piorities - if the clickorlando.com news story is true, the gneral manager of the fabrication company strongly pushed for no seatbelts:

New records released by the FDACS show that the General Manager of Funtime Thrill Rides, Hannes Lackner, advocated for no seat belts on Orlando FreeFall.

“The seat and shoulder restraint system…has 2 independent locking devices, and the shoulder restraints are monitored. It is no need for an extra safety or seat belt because the seat and restrain system fulfill more than the requirements,” Lackner wrote in a letter attached to the ride’s user manual.

If Mr. Lackner's opinion was the last say on safety systems of the ride or if he strongly swayed the decision of the FMEA review team, the oversight of a rdundancy to the over-shoulder restraint is rather ominous.

It is still not clear to me if the rider was so large that the restraint was able to latch and indicate a latched condition but its structure/support was deflected such that the rider was able to slide from under the restraint and over/around the between-the-legs upriser or was the restraint in a partial latched condition and the indicator falsely showed a latched condition. After the rider slid out the restraint fully latched itself and thus its condition when the ride was checked after it was lowered and stopped? For the kid to have slid over the upriser while squeezed by the restraint must have been painful or injurious or the restraint wasn't restraining.

RE: Amusement Park ride tragedy

The 'kid' was bigger than most adults... ponder

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

RE: Amusement Park ride tragedy

(OP)
Yes - Tyre was a big kid! His tragic death highlights the challenge of engineering a product that has the risk of injury or death to a human. Obviously, the intent for this ride is not to kill anyone but with the tragedy that has happened some assumptions/analysis models and guidances for ride restraint systems at Funtime Group will probably change.

https://www.wfla.com/news/florida/20-seat-belt-cou...

RE: Amusement Park ride tragedy

Or maybe the requirement for someone supervising the ride be older than 18 (or more)? Funny that it would happen in Florida... do they have a minimum age?

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

RE: Amusement Park ride tragedy

The actual operator's manual for the ride was posted by the State of Florida, along with inspection records and other things, here: https://www.dropbox.com/sh/7oss0c7w8d2i3h1/AAAeOaA...

I read through most of it and there are supposedly numerous sensors all over the ride including two for each seat that will not let the ride run unless the harness is locked. The claim is that the harness was actually locked. As someone above said, did the harness lock itself AFTER the kid fell out? This ride has a ton of monitoring via PLCs including a separate dedicated "safety PLC." I wonder how much logging those PLCs do. The manuals don't seem to mention much about logging other than error logs... Would be nice to know "Seat 5 latch 1 locked at 3/27/22 15:03:05"

RE: Amusement Park ride tragedy

The other potential weak spot for this operation is the lower up riser which prevents people sliding out under the harness or between the upriser and the base of the over shoulder harness.

The unfortunate victim was above the weight limit for the ride and they also usually have other parameters like chest size and maybe thigh girth.

Kind of difficult to measure those in a theme park setting, but they are there.

I've seen dummy seats in the queue line to allow people to see if they fit - not sure if they do that there?

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

RE: Amusement Park ride tragedy

my similear thoughts. . .

given young mans height and chest girth, the between the leg protrusion was left far above the seat, (and the thickness of hips had his CG over the edge of the seat)

the over the shoulder did restrain during negative G of initial fail, but during positive G deceleration, he submarined out of the seat/restraint.

given knowledge of the basic forces of fall/decel AND with fall protection harness I wouldn't get on that ride with out at least a 5 point harness


there is NO way a teenage operator could begin to grasp the consequenses of devetations of outside the limit riders

RE: Amusement Park ride tragedy

I find it hard to believe they would design the locking systems so it would lock with the shoulder harness so far out there is a big enough gap between it and the seat that someone can submarine out of the seat. I would think the seat and notch in the restraint would have to be together before it would latch. It'd be a very stupid design flaw to latch it with a big opening.

I tend to think it was a false latched indication. I wonder if he had shoved the restraint open on the way up if the ride would have aborted?

RE: Amusement Park ride tragedy

Park is claiming the restraint was locked. Unless the restraint has more than one position in which it can lock, then I don't buy it. Photos of the boy on the ride clearly show that his shoulder restraint is up higher than anyone else's. I suspect it wasn't latched, but after he fell, the braking and 'impact' of the stop at the end of the ride was enough to settle the restraint into its latch.

RE: Amusement Park ride tragedy

Most have some sort of ratchet and a number of locked positions to account for the different sizes of people.

If you look at the photo of the seats with no one in I posted, you can see in an empty situation the shoulder restraint is locked way behind the upstand such tat anyone in it would need to be about 6" thick.

The question is then did the largest setting on the restraint allow someone to submarine out of it and did it in fact lock them in tight enough to start with.

I'll be looking harder at these seats the next time I go on one.

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

RE: Amusement Park ride tragedy

Quote (LittleInch)

The question is then did the largest setting on the restraint allow someone to submarine out of it and did it in fact lock them in tight enough to start with.

There's an important sub-question that I haven't seen asked yet..

The victim here was well over the published passenger weight limit for the ride. If the restraint is locked on the largest setting but the passenger being restrained is at or under the weight limit, is submarining still possible?

RE: Amusement Park ride tragedy

Quote:


I tend to think it was a false latched indication. I wonder if he had shoved the restraint open on the way up if the ride would have aborted?

Page 115 of the operating manual seems to indicate that a seat that becomes unlocked will trigger a Warning--not an abort. I believe "Z-Stop" would effectively be an "abort" but returning the ride to the unloading position would be performed manually by the operators (in the manual, they detail this as "evacuation mode" in another section).



RE: Amusement Park ride tragedy

...and the 16 year old kid in charge obviously read the manual. ponder

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

RE: Amusement Park ride tragedy

Is it possible the rider was holding the restrant bar down but it wasn't able to latch but was able to close the limit switch? (Badly positioned proximity switch or proximity switch with a washer taped to it) In my experience PLCs aren't much for logging unless there is a software package or an HMI connected to it, considering the level of complexity (seperate safty PLC) an HMI seem very likely. Hard to imagine you could start a ride cycle with a unlatch signal active.

RE: Amusement Park ride tragedy

There are LOTS of rides with age, height, or other restrictions; I recall an acquaintance that hosted a birthday party for their kid at Disney, but he was too short for a number of rides. There was presumably a weight/size limit on the ride in question. How the victim got through that wicket is a problem, followed by the sequence of events relative to locking the restraints. Nevertheless, had there been a serious safety culture at the park, the victim should have been barred from the ride if there was even a hint of issues with the restraints.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

Nail on the head, IRS...

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

RE: Amusement Park ride tragedy

You would sure hope that the locking indicators checked that the locks were engaged and not that the bar was only down a certain amount. I find it very hard to believe the designers would be that stupid.

RE: Amusement Park ride tragedy

(OP)

Quote (Sym P. le)

It's absolutely astonishing that no testing exposed this design flaw. I question whether these over the shoulder systems were even intended for use in this orientation.

It will be surprising to find the Funtime Group engineers did not do sufficient boundary testing to uncover the safety flaw of the potential for an over-sided rider to submarine out of the restraint. The engineering on these type of rides is very complex and the teams that design them are highly skilled. It does appear as others have pointed out maybe the hazard induced by adding the 'tilt outward' feature was not caught or overlooked? With the ride chair sitting at the starting angle an over-sized rider's CG is probably inboard of the point of restraint created by the over-shoulder restraint and the chair cup and upriser. When the 'tilt outward' position is created by an active drive operation at the top of the lift just before the drop the over-sized rider's CG could be inline with or outside the point of restraint created by the shoulder restaint/seat system. Thus allowing a slide condition to be possible with greatly reduced normal force creating less friction to keep the rider in place. A 'normal' size rider's CG or 'under-sized' rider's CG would never move to be coincident or outside the point of retention. I am not familiar with the safety requirements in the amusement ride industry but in the medical world consideration for mitigating normally expected misuse/improper use of a system is common and often debated on how far must mitigation be conducted to protect those who may knowingly or sometimes unknowingly put themselves or others at risk.

RE: Amusement Park ride tragedy

The CG of an object does not change with orientation,

RE: Amusement Park ride tragedy

I believe it can move in the human body.

Mostly due to fluid movement.

RE: Amusement Park ride tragedy

(OP)
I should have been more clear - the line of action of the CG in relation to the acceleration. point of retention.

RE: Amusement Park ride tragedy

I think you might be surprised at how few engineers there are in those companies.

Any that can sign off not having a seatbelt attachment which would prevent accidental submarining for what would be incredibly minor additional action should be worried.

It would also act as a go/no go if the belt didn't attach because the shoulder restraint wasn't down far enough. I've seen that in action on rides I've been on and it works.

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

RE: Amusement Park ride tragedy

(OP)

Quote (LittleInch)

I think you might be surprised at how few engineers there are in those companies.
That is surprising - my impression is formed mainly by stories describing the high level of stress analysis and simulation that goes into theme park ride design. Often the credentials of the teams described are quite impressive.


Quote (LittleInch)

It would also act as a go/no go if the belt didn't attach because the shoulder restraint wasn't down far enough. I've seen that in action on rides I've been on and it works.
Yes, a simple additional belt mitigates submarining and reduces the risk dramatically.

RE: Amusement Park ride tragedy

Quote (It will be surprising to find the Funtime Group engineers did not do sufficient boundary testing to uncover the safety flaw)


From the partial printout of the error codes, it may be a user/operator error. We have to wait and find out...

Quote (I think you might be surprised at how few engineers there are in those companies)


ditto...


Quote (Any that can sign off not having a seatbelt attachment which would prevent accidental submarining for what would be incredibly minor additional action should be worried.)


It might be like having a seat belt included with a 'baby carseat', in addition to the restraint. It may be unnecessary... we have to find out. It may be with the accellerations involved, the seat belt may be dangerous. The restraint may be 'foolproof', realising fools can be ingenious.

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

RE: Amusement Park ride tragedy

Quote:

That is surprising - my impression is formed mainly by stories describing the high level of stress analysis and simulation that goes into theme park ride design.

Safety analysis and design often takes the short shrift when it comes to design; it's often applied only after the main structural and functional design takes place.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

RE: Amusement Park ride tragedy

I don't see that as a smoking gun; the issue is whether the victim was covered by the requirements. If no, then the design wasn't specifically an issue; it would be no different than if someone followed seismic design requirements, and the "Big One" turned out to be 10x bigger than the requirements. The usage and operator control would still have been an issue, regardless.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

Anybody know what category 5 system means, I'm familiar with SIL(safety intergaty level) levels but they only go to 4.

May mean class 5 restraint system Link

RE: Amusement Park ride tragedy

Quote (Safety analysis and design often takes the short shrift when it comes to design)


It's like Crunchy Froggie, it wouldn't be death defying, then, would it. pipe

https://www.youtube.com/watch?v=e-5h0L-SSqk

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

RE: Amusement Park ride tragedy

But why was that letter issued on 19th JAN this year?

This can only be a result of something else that happened or was in question. You don't issue letters like that for no reason.

And it leaves more questions.
Cat 5 to what standard? As stated it is meaningless. You could say Cat 1000,

What "requirements"???
What TUV standards???

The letter says nothing.
IMHO.

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

RE: Amusement Park ride tragedy

RE: Amusement Park ride tragedy

(OP)

Quote (IRStuff)

I don't see that as a smoking gun; the issue is whether the victim was covered by the requirements
Yes, good point - this ride is stated to meet some type of requirements. So what is the standard/requirements? And possibly those requirements are deficient if they don't consider boundary conditions.

Quote (LittleInch)

But why was that letter issued on 19th JAN this year?

This can only be a result of something else that happened or was in question. You don't issue letters like that for no reason.
I think the ride was constructed in Dec. 2021 Maybe during commissioning of the ride someone asked 'Hey, where the seatbelts? Did they forget to send them?'

RE: Amusement Park ride tragedy

(OP)

Quote (Cool Controls)

May mean class 5 restraint system Link
Wow - the project report in the link is very detailed. It does mention there are no mandatory federal standards, only voluntary use of ASTM standards.

RE: Amusement Park ride tragedy

Although the catagory does not seem to be properly referenced, it does appear to conform to Class 5 in the document shown. In particular the last 3 items, and possibly 4 items. It's also nice to see the applicable ASTM docs referenced, just to know what ones might be required:



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

RE: Amusement Park ride tragedy

Quote:

And possibly those requirements are deficient if they don't consider boundary conditions.

Safety requirements are functional, it's up to the designer to identify the boundary conditions and design accordingly, and limit usage accordingly. Otherwise, safety requirements couldn't not even be written; can you imagine trying to anticipate the boundary conditions for this particular ride before anyone even knew they wanted to design one?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

(OP)
IRStuff good point as was your previous one about if there was a serious safety culture in place at the park, all operators would have felt empowered to deny Tyre entry into rides he was outside the allowable limits.

RE: Amusement Park ride tragedy

Yes.

Did they feel empowered? To what extent? In particular, was that true for the particular ride operator at the time?

If they felt empowered at the time, did they feel the need to act on that empowerment? If they did not, why not?




spsalso

RE: Amusement Park ride tragedy

Quote:

Did they feel empowered? To what extent? In particular, was that true for the particular ride operator at the time?

If they felt empowered at the time, did they feel the need to act on that empowerment? If they did not, why not?

That's a valid point; people, in general, tend to want to avoid conflict; this might have been coupled with some level of intimidation factor of potentially conflicting with someone who is taller and heavier.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

Cat 5 also calls for
"Redundant locking device function"
And
"Two restraints or one failsafe function"

Difficult to see those at the moment.

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

RE: Amusement Park ride tragedy

Class 5 allows for a varible latching position, it seems to me all the redundancy is meaningless if the latch position is not close enough to the rider, but I guess that's where the operators come in.

RE: Amusement Park ride tragedy

Quote (Class 5 allows for a varible latching position, it seems to me all the redundancy is meaningless if the latch position is not close enough to the rider, but I guess that's where the operators come in.)


It could be that the occupant is much larger than the limiting size; it the latching/test devices could be inoperable, for some reason. We have to wait until more information comes out.

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

RE: Amusement Park ride tragedy

There's an even more interesting legal dilemma. How do they go about improving the safety training and enforcing limitations on the equipment, without admitting to liability for not having these procedures in place, prior to the accident?

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

RE: Amusement Park ride tragedy

The American way, dead kid on the ground, nobody's fault. Blood money.

RE: Amusement Park ride tragedy

"...they can set the terms,..."

I don't think so. If there is a settlement, the terms of settlement are mutually agreed upon. If both sides don't come to an agreement on those terms, it goes to trial.

The defendant cannot unilaterally set those terms. Neither can the plaintiff.

IF there is a "non-admission of fault", it will have been accepted by the plaintiffs. And it will only apply to this case.


spsalso

RE: Amusement Park ride tragedy

I suspect all parties have been in contact with their lawyers, by now, who will direct them from this point forward.

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

RE: Amusement Park ride tragedy

Its reported this side of the pond that the kid was 150kg/340lbs.

I don't think any pax carrying standard would require that load to be taken into account.

By rights he wouldn't have been able to sit in a pax aircraft seat. Although this is a contentious subject if you can deny a pax that would over load the seat.

RE: Amusement Park ride tragedy

There is no max passenger weight on us airlines although they can make you purchase a second seat. Have seen what American football players look like?

RE: Amusement Park ride tragedy

There isn't on any airline.

But if you look at the certification of the seats its shall we say amusing what gets stuck on them.

The belts are also amusing think its 2000lbs and 16g they are designed for. But when questions came up I answered I suspect that more than that the person would be garrotted in two anyway with only a lap belt.

There has been talk about changing the certification specs for average pax weight and floor loadings. But there is extreme lobbying not to change anything and leave it as it is.

The main issue is that seats are becoming detached from the floor in runway overruns and other none fatal incidents and its causing injury's to the rows in front occupants.

Although we are getting into 737 grandfathering issues yet again on that one as well.

RE: Amusement Park ride tragedy

Quote:

I don't think so. If there is a settlement, the terms of settlement are mutually agreed upon. If both sides don't come to an agreement on those terms, it goes to trial.

Fair enough, but I've not seen many civil suits where part of the settlement included an admission of guilt, because that's usually absurdly difficult to get to, and only governments can usually afford the litigation to get to that stage.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

Quote:

I think you might be surprised at how few engineers there are in those companies.
Any that can sign off not having a seatbelt attachment which would prevent accidental submarining for what would be incredibly minor additional action should be worried.

I know several major companies that design theme park rides including a former employer. My experience matches Brian's with them, the teams working on these rides tend to be very impressive bc the customers tend to be high-profile and requirements very demanding.

JMO but I wouldn't be particularly concerned by the lack of a seatbelt, many rides with similar over the shoulder harnesses don't have them including some hanging coasters with similar tilt-seat arrangements to mimic flying. I can imagine quite a few ways of redundantly locking the harness at the pivot and would view that as preferable to relying on a human locking a seatbelt. I'm also not particularly surprised to hear kids were questioning the safety mechanisms while waiting for the ride to launch, its what folks do to freak out nervous friends/relatives...and yes, BTDT.

RE: Amusement Park ride tragedy

Quote (Brian Malone (Industrial) (OP) 6 Apr 22 03:44)

According to this story Tyre was 380 lbs. And the ride entry queue does not have a weighing device for riders.
https://www.clickorlando.com/news/local/2022/04/05...

You missed the lede ...

Some seats were adjusted for larger body types and the victim was directed to sit in one of those seats.


RE: Amusement Park ride tragedy

You wonder what sort of adjustments they made?

The safety check before the ride starts is the weak point in this being a repetitive task undertaken by young ride operators.

There may be some checks on the harness lock, but if the secondary seat belt click is both an easy visual and practical check, but give you that crucial level of redundancy. I just can't really see why this is somehow seen as any sort of onerous additional action.

The length of these is fixed and hence requires the harness to be pulled down to some sort of minimum level leaving not enough space for someone to escape under the harness.

The fact in that photo that the seat has been removed may also be crucial as the lower between the legs bump is a critical part of the restraint.

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

RE: Amusement Park ride tragedy

Were those modifications for larger riders officially approved by the manufacturer?

RE: Amusement Park ride tragedy

Was trying to think of a way to prevent overload without resulting in court cases about embarrassment.

Only thing I could come up with is an interlock that blocks the restraint coming down if its over the weight limit.

Which then removes the human from the decision making.

RE: Amusement Park ride tragedy

And adding to the cost, as every seat would need a weight sensor.

RE: Amusement Park ride tragedy

Cheaper than killing someone or being sued for a young kid saying get off fatty.

RE: Amusement Park ride tragedy

"You must be this tall to ride", how many times have I seen those words. How about a weight limit.

RE: Amusement Park ride tragedy

You could weigh everyone

Just as you test everyone for height.walking past the height gauge.

Interlock tests everyone.

RE: Amusement Park ride tragedy

I have seen chest size limits posted on some rides in the the UK which at least is an easier thing to measure and not related to the weight or perceived obesity of the individual.

IR stuff - other pictures show the seat and side restraints were there on the night - I suspect they have removed these for testing, hence my question / point that the harness may have done it's job, but the seat is an integral part of the restraint with the side elements and the upstand between the legs.

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

RE: Amusement Park ride tragedy

There's a huge difference between 280lbs and 380lbs. If the mods were done without the approval of the supplier someone could be in serious trouble. As far as weight it's a simple matter of rigging a spring device that would send an alarm if the 280lbs were exceeded... I used a little strip of phosphor bronze to rig a blasting cap mouse trap, back in grade school... no rocket science. The seat 'enclosure' looks to be pretty robust and little room to excape from if it was properly secured. Someone should be charged with negligent homicide...

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

RE: Amusement Park ride tragedy

Dik: note 'wog' is a very derogatory term in most of the UK.

Common in the 1960's but like the 'N -word' here now.


Politicians like to panic, they need activity. It is their substitute for achievement.

RE: Amusement Park ride tragedy

My fault sorry Pud, i would only ever use that word in that context and in relation to myself as a Scotsman. If its caused offense I apologise.

RE: Amusement Park ride tragedy

thanks Pud... gone... will not repeat.

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

RE: Amusement Park ride tragedy

It stands for worthy oriental gentleman, as pud says it was mostly used as a derogatory term. Have a google for the TV show "in sickness and in health" to see how offensive manner it was used. You really wouldn't hear it today thankfully in the street. it originates from the British army in Hong Kong .

That phrase in relation to Scotsmen was and still is used in the British army by all. Scottish soldiers do refer to themselves as such. Its more humour than anything else. We had one 3rd generation Indian descent lad from Glasgow who referred to himself as a cashew porridge wog. Which I must admit defeated most on the humour front. Scottish are also referred to as sweat which is short for sweaty sock cockney slang for jock. Welsh were called Taff and Irish Pad. I certainly never felt offended by it.


Sassenachs is used in relation to the English by the Scottish and is used in a more of an offensive manner, The other term which is commonly used in small communities is "white settler" which is always used in an an offensive manner. Its linked to city people coming in and buying property and trying to take over the local community. If I would say buy a property in some village on the west coast for retirement and then come in and then made some radical change, say put solar panels in on the roof and people didn't like it I would be referred to as that because I am not local and from Aberdeen.

RE: Amusement Park ride tragedy

Quote:

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
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

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 :D

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

New update from news in South Florida:
https://www.local10.com/news/florida/2022/04/18/se...

Here is the report:
https://www.dropbox.com/sh/7oss0c7w8d2i3h1/AAAeOaA...

All part of this public dropbox published by Florida: https://www.dropbox.com/sh/7oss0c7w8d2i3h1/AAAeOaA...

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?

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

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...

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

Exercise would do him good? ponder

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

RE: Amusement Park ride tragedy

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





RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Amusement Park ride tragedy

This is interesting https://www.cdc.gov/nchs/data/series/sr_03/sr03-04...

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.

RE: Amusement Park ride tragedy

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? pipe 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

RE: Amusement Park ride tragedy

Quote (dik)

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.

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

"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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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. pipe

https://www.clickorlando.com/news/local/2022/03/29...

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

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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/products/specia...

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

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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?

RE: Amusement Park ride tragedy

Quote (Safety switches should never be mounted in the manner shown.)


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

RE: Amusement Park ride tragedy

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/Tamperi...

RE: Amusement Park ride tragedy

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.

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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?

RE: Amusement Park ride tragedy

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

RE: Amusement Park ride tragedy

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.

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