Dreamworld becomes Nightmareworld - Page 1
Forum section: electronics / general

author: raptor1956
author_rank: Frequent Contributor
timestamp: October 26, 2016, 03:59:39 am
content: I just saw an article about a theme park ride accident near Brisbane that claimed the lives of four people but that two teenage girls somehow managed to survive. They did not do into the gruesome details beyond saying the dead were killed by a conveyor belt.http://www.cnn.com/2016/10/25/world/queensland-theme-park-fatalities/index.htmlBrian

author: TerraHertz
author_rank: Super Contributor
timestamp: October 26, 2016, 04:06:52 am
content: It's one of those 'best not to google it' things.

author: raptor1956
author_rank: Frequent Contributor
timestamp: October 26, 2016, 04:54:52 am
content: Yeah, I'm not interested in seeing gore and the stuff you might see on LiveLeaks etc -- just reported what I read about an event taking place in the home of EEVblog.Brian

author: EEVblog
author_rank: Unknown
timestamp: October 26, 2016, 05:48:48 am
content: Quote from: TerraHertz on October 26, 2016, 04:06:52 amAFAIK there is no gore to be seen.Yes, 4 people were killed and two kids survived (the raft holds 6 people). Sadly the kids of one of the women killed were watching as it happened (the conveyor belt is right near the public viewing platform)The raft got hit by another raft and flipped, two people trapped under and two people flipped out, all 4 of whom were killed. Unknown how the two kids survived.What I find remarkable is how it happened. This is a fairly sedate rafting ride you can take 2yo's on (I took Sagan on it last year) and has been operating for decades. So seems remarkable that an incident like this only occurs now.

author: EEVblog
author_rank: Unknown
timestamp: October 26, 2016, 05:52:00 am
content: It's the worst theme park accident since the Luna Park fire in 1979https://en.wikipedia.org/wiki/1979_Sydney_Ghost_Train_fire

author: aargee
author_rank: Frequent Contributor
timestamp: October 26, 2016, 05:55:17 am
content: Actually they were all adults killed. Looks like one jammed on the start of the conveyor and another came up on the rear and overturned it.The ride has been there since the mid 80s. Been on it with our two when they were munchkins many years ago.Stuff happens, wrong place at the wrong time.

author: EEVblog
author_rank: Unknown
timestamp: October 26, 2016, 06:12:05 am
content: Quote from: aargee on October 26, 2016, 05:55:17 amYep, freakish conditions. Surely these boats have bumped into each other at that spotted many times in the past?

author: zl2wrw
author_rank: Regular Contributor
timestamp: October 26, 2016, 07:20:26 am
content: Quote from: raptor1956 on October 26, 2016, 04:54:52 amYep, I second that.However, I am interested in the cold hard details of what went wrong, and what mistakes were made - I'd rather learn from other's mistakes instead of making the same mistakes myself...

author: StuUK
author_rank: Frequent Contributor
timestamp: October 26, 2016, 08:14:11 am
content: wow, 9 posts in and off topic already

author: EEVblog
author_rank: Unknown
timestamp: October 26, 2016, 08:21:55 am
content: Quote from: StuUK on October 26, 2016, 08:14:11 amPost deleted.

author: EEVblog
author_rank: Unknown
timestamp: October 26, 2016, 08:28:47 am
content: Quote from: zl2wrw on October 26, 2016, 07:20:26 amI'd be a bit surprised if mistakes were made here. I'm guessing the finding will be freak unforeseen accident.These boats are designed to bump into each other, although IIRC that's not the normal mode of operation, but not unusual and would have happened countless times before. Might just be a case of bumping into each other at the wrong point and the wrong angles etc.

author: Brumby
author_rank: Unknown
timestamp: October 26, 2016, 09:04:19 am
content: From what I have seen on tonight's news, the accident occurred between two sections of the conveyor system.The conveyor section at the front (conveyor A) failed and the raft (call it Raft 1) on that one rolled back. The conveyor section behind (conveyor B) was still operating and tried to push the raft (call it Raft 2) that was on it into Raft 1. Raft 1 didn't move and the front of Raft 2 then lifted up over the back of Raft 1.This is when the problem got serious.There was a gap between the two conveyor sections (about 40cm, I believe). Normally a raft will get moved by Conveyor B which will then cross the gap and Conveyor A will take over and continue to move the raft. When rafts pass over this in normal operation, the gap is quite insignificant - but what was happening was not normal.....As the front of Raft 2 rose up, the rear dropped down and slipped into the gap. The front of Conveyor B caught the rear of the raft and dragged it into the gap.I'll say no more....

author: Jeroen3
author_rank: Super Contributor
timestamp: October 26, 2016, 11:20:31 am
content: I couldn't believe people were killed in such ride at first. But it looks like there are large gaps in the conveyor. I can unfortunately imagine that you can get stuck in those gaps.There is a similar ride in the Netherlands, but the gaps on the conveyor are smaller.

author: TerraHertz
author_rank: Super Contributor
timestamp: October 26, 2016, 11:45:42 am
content: Quote from: raptor1956 on October 26, 2016, 04:54:52 amI wasn't referring to visual gore, there's none.It's the engineer's visualization of the accident process, once you learn the mechanism, that would best be skipped.Probably OK for those without vivid imagination.

author: raptor1956
author_rank: Frequent Contributor
timestamp: October 26, 2016, 08:10:19 pm
content: It's pretty hard to envision every possible failure mechanism and provide controls to prevent it. And, even when you can envision it it may be impractical to develop a control to prevent it. We don't live in rubber lined rooms and thankfully so.With what little we know at this point it's safe to say the conveyors played a role though just exactly what and how has yet to be detailed. I wonder if they have torque monitoring on the motors driving the conveyor and if so what the torque profile looked like before, during and after.Ultimately four people lost there lives and the two children that survived witnessed something you would not want a child to endure. Keep them in you thoughts...Brian

author: Jeroen3
author_rank: Super Contributor
timestamp: October 26, 2016, 08:32:57 pm
content: It's the dark side of engineering. Some things have to fail for us to learn and improve.We've lost many planes to get to current standards.

author: Cyberdragon
author_rank: Super Contributor
timestamp: October 27, 2016, 03:39:28 am
content: Quote from: raptor1956 on October 26, 2016, 08:10:19 pmTorque sensing might work, but it's finicky (how much torque is dangerous?). A better system would be proximity sensors of some sort (lidar, sonic, radar) on the end of each conveyor and a little way before the end of the back conveyer to monitor the passing rafts and check for obstructions.

author: Brumby
author_rank: Unknown
timestamp: October 27, 2016, 05:34:50 am
content: Rather than getting fancy about sensing if something might be falling down the hole - why not just block the hole?I would think a better system would have been to fill the gap with a simple bit of framework. It could be an inch below the normal path of the rafts, so it wouldn't interfere with the exiting operation and mounted with a few bolts that could easily be removed for maintenance.

author: dmills
author_rank: Super Contributor
timestamp: October 27, 2016, 08:36:37 am
content: Thats the fix I would instinctively try for, passive safety is almost always better then active systems.Apart from anything else some poorly trained operator is less likely to override a passive safety system (Poured concrete also trumps bolted on metal here if you can manage it).See the accident at Alton towers in the UK where a rollercoaster had multiple cars in movement at the same time (Well it increases numbers of riders per hour) with railway style block interlocking for safety. While fixing an issue someone overrode the interlocking with a stopped car part way around the track).The automation know there was a problem and was holding the next car waiting for the block ahead to clear, but the maintenance "Engineer" (Who had not read the O&M manual, and had not actually been out to eyeball the blocked section) 'knew' better.Result of the coming together, several teenagers with leg amputations and a £5M fine for the operating company plus civil settlements to come.The sort of thing that any engineer is both shaking their head at and quietly thinking "There but for the grace... go I".Regards, Dan.

author: jonovid
author_rank: Super Contributor
timestamp: October 27, 2016, 10:05:11 am
content: a final word from Me . looking at the role of electronics in amusement park rides.situational awareness of passenger unit separation and some type of automated alarm system may of saved lives here. and is probability is true of all amusement park rides. that use independently moving Passenger unit's on the same shared Line. be it gravity propulsion and or motorized.

author: nctnico
author_rank: Super Contributor
timestamp: October 27, 2016, 10:59:06 am
content: Quote from: Brumby on October 27, 2016, 05:34:50 amI agree. Something like that is simple to make and prevents a raft from being pulled down. It still doesn't prevent a raft from flipping over. IMHO the conveyor belt should be fully closed so people can't fall through it. As Jeroen3 noted there is a similar ride in the Netherlands and IIRC the conveyor belt is fully closed (*). You could walk on it if necessary. There are European safety regulations for conveyor belts and I'm quite sure these also apply to amusement park rides.Edit: * The belt is closed:

author: StuUK
author_rank: Frequent Contributor
timestamp: October 27, 2016, 11:03:33 am
content: If wonder if Disney are reviewing their similar rides?https://youtu.be/Jdp_YAFcqtU?t=370

author: @rt
author_rank: Super Contributor
timestamp: October 27, 2016, 11:24:21 am
content: In my 20's I bashed my face on whatever surface was in front of me on the log ride as it hit the water at the end of its last drop. It hurt, but I didn't know I had blood all over my face. The way out after the ride is over leads you straight past the que of people waiting to get on next. They all looked at me in horror, and the staff were eager to shuffle me on out of view. Not once did any staff ask if I was ok, or offer any first aid. I was fine, but no one observing could have known that.

author: Shock
author_rank: Super Contributor
timestamp: October 27, 2016, 11:51:12 am
content: Was reminded of this

author: StuUK
author_rank: Frequent Contributor
timestamp: October 27, 2016, 12:30:21 pm
content: BIG Difference, the guy was in control of his ride (or not if you get my meaning) and was just being a wanker and clearly not obeying the signs or maybe couldn't read German but still a wanker either way...

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: October 27, 2016, 12:43:28 pm
content: Quote from: Shock on October 27, 2016, 11:51:12 amThat guy was a complete pillock. At 5:07 he hits her a third time deliberately and gave the child a shunt that could have damaged her neck/spine. If I was her dad and saw what he did (I'm sure she told her dad afterwards), I might have chucked the guy over the hillsShe was in tears and struggling to walk

author: nctnico
author_rank: Super Contributor
timestamp: October 27, 2016, 03:39:19 pm
content: What a complete A-hole! And if he just waited a bit longer he could have gone as fast as he wanted!

author: rrinker
author_rank: Super Contributor
timestamp: October 27, 2016, 11:34:12 pm
content: Yeah I'd kind of like to ride one of those but I would have to go when the place is like completely empty because I would go soooo slow. Anyone behind me would just completely hate me, unless they waited until I was almost finished to start off. Then again, maybe I would like that, since you do have some semblance of control, and I like to drive fast - but I hate coasters, I just don't go on them. Someone once said - but you like the drive fast, it's the same thing. No, when I drive fast I'm in control of the car, not at someone else's mercy. Kind of like those IndyCar and NASCAR ride-alongs - I want to do the one where you drive the car, I have no desire to be in the right side seat being driven by someone else to within an inch of the outside wall.

author: timb
author_rank: Super Contributor
timestamp: October 28, 2016, 02:24:22 am
content: Quote from: rrinker on October 27, 2016, 11:34:12 pmFinally, someone who gets it! My friends can never understand how I can drive a motorcycle at close to 200MPH or take the corners of a track at 85MPH in my car, yet not like roller coasters.The difference is *I'm* in control. *I* meticulously maintain my vehicles, so I know what they're capable of. I also know my car isn't going to break down and leave me hanging upside in a loop for 3 hours, but a roller coaster can (I've seen it). There's very few things I can imagine that would suck worse than that!

author: raptor1956
author_rank: Frequent Contributor
timestamp: October 28, 2016, 03:10:11 am
content: Quote from: Cyberdragon on October 27, 2016, 03:39:28 amAgain, it's still too early to know what actually happened and what the remedy might be. And, as others have mentioned, there's both active and passive controls that might figure into it. My take is that you use passive controls to the extent that you can and then you use active controls for additional safety margins. I mentioned torque monitoring not because I thought that would solve the problem but because it might provide a sensing mechanism that if other systems failed, might stop the ride so that the operators and support techs could look into it.You might have a component that can get hot and the passive control is better ventilation, but you still want to measure the temperature...Brian

author: nctnico
author_rank: Super Contributor
timestamp: October 28, 2016, 10:17:26 am
content: Quote from: nctnico on October 27, 2016, 03:39:19 pmParenting hint: always be the one behind your kids on rides like these and water slides. I have been doing that when my kids where little and appearantly for good reason.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: October 28, 2016, 11:51:53 am
content: Quote from: nctnico on October 28, 2016, 10:17:26 amI think the dad went in front because he was keeping his "daughter" (assumption) at a pace and he had his youngest with him in his car.You can't cater for a person behind being a douche.

author: rrinker
author_rank: Super Contributor
timestamp: October 28, 2016, 07:13:10 pm
content: Yeah if the Dad was in front with a smaller child riding along, it could have been WORSE when the douche rammed from behind if he was behind the older girl. The idiot was just too impatient - he nearly bumps the girl once, then lightly bumps her, and then finally the big bang. After the first time you'd think it would light up a brain cell or two that would say, wait a little longer so the ones in front of me can get out of the way. Or at least after the second time when he actually did bump her. But nope. Common sense - let them get further ahead, then you can go as fast as you want. But nope, all too lacking in society these days.