Incident on The Smiler 02/06/2015

[phildenholm]

Is that what I said? A ride that stalls is badly designed but the stall shouldn't be a risk factor as the safety systems should prevent other trains entering that block, that's why the block system is the crux of this.

Any ride could stall if something affected a wheel bogie badly enough, hence why all coaster manufacturers plan for it even if they have no history of it.

I doubt the HSE or Merlin will see the stalled car as "not relevant" which is what you said IMO it is relevant and an issue that needs addressing before the ride can open again, can you imagine the panic the next stalled car would cause?

 

[delta79]

No unweighted trains to go onto track.

 

[JayM]

Ride control system/procedure alterations should be the focus of improvements. Stalling is a (relatively) common occurrence in the industry, two trains being in the same block is not.

On the subject of stalling, I doubt a normal, safe evacuation would take 4 hours - the nature of injuries would have lengthened this. In terms of getting the ride operational again, a stall also would not damage cars (and potentially other infrastructure) unlike a block system failure with a stalled car, or cause any harm to people.

 

[Tom]

The HSE investigation will spend minimal time on why the train stalled. They will not be looking to establish why the ride was poorly designed that it is occasionally unable to complete its circuit. I would have thought it pretty obvious, but their investigation will focus on how the other train was able to continue on its way. The stalled train is immaterial.

 

[Dave]

I doubt the HSE or Merlin will see the stalled car as "not relevant" which is what you said IMO it is relevant and an issue that needs addressing before the ride can open again, can you imagine the panic the next stalled car would cause?

The HSE would be finding against themselves if they see the stall as the cause seen as they have for two years allowed the ride to operate knowing it can stall.

A lot of rides stall, B&M are pretty much the only manufacturer who avoid it completely. They will be looking at the block system, as that's what has failed.

The stall is relevant only as part of the sequence of events.

 

[MichelinMan]

The HSE would be finding against themselves if they see the stall as the cause seen as they have for two years allowed the ride to operate knowing it can stall.

A lot of rides stall, B&M are pretty much the only manufacturer who avoid it completely. They will be looking at the block system, as that's what has failed.

The stall is relevant only as part of the sequence of events.

Dave, do you know for a fact that the HSE knew it stalled? Because unless somebody told them about the stalls, they probably wouldn't know about them - there is nothing in the reporting regulations RIDDOR that would require them to tell the HSE.

You are right in that the fact that a coaster stalls is not necessarily a major concern in itself. But when you design safety instrumented systems, you normally need to make assumptions about how often such safety systems will be required to operate - the so called 'demand rate'. Then, once you know the demand rate, you can work out how reliable the safety systems need to be to give a required safety integrity level. One thing the HSE will probe is what the design 'demand rate' for the ride was in terms of stalling - if it has stalled more often than anticipated, then there is a higher chance that any other safety systems may be deficient.

Way back in this thread, somebody mentioned the Swiss cheese model. You can think of the ride stalling as being the first layer in the swiss cheese - if it didn't stall, there couldn't have been an accident. The more often the ride stalls, the more 'holes' are in the first layer of the swiss cheese, and you need more rigorous safety levels in your remaining layers of cheese -or less holes - so that the gaps don't all line up. I suspect that is what has ben going on the previous few days - beefing up those other 'layers' so that they have less holes.

 

[Danza91]

Way back in this thread, somebody mentioned the Swiss cheese model. You can think of the ride stalling as being the first layer in the swiss cheese - if it didn't stall, there couldn't have been an accident. The more often the ride stalls, the more 'holes' are in the first layer of the swiss cheese, and you need more rigorous safety levels in your remaining layers of cheese -or less holes - so that the gaps don't all line up. I suspect that is what has ben going on the previous few days - beefing up those other 'layers' so that they have less holes.

Interesting, I mentioned Dr. James Reason's 'Windows of Opportunity' theory a while back but never knew it is more widely known as the Swiss Cheese model!

Reading around, it's amazing the amount of people which seem believe that it's possible for things like rollercoasters to be 100% safe. As part of my work, I'm involved in a lot of health and safety films and the theme is the same, you cannot make anything 100% safe, you can only reduce the risk of an accident making it extremely unlikely to happen. The possibility is always there. That's life!

 

[AirFAN]

Just watching a video on YouTube of the ride testing (assume from prior to opening). The speed at which the train comes out of Batwing really is slow. I haven't been on the ride myself - was anything done to improve this after ride opening? Clearly it has stalled in the past but at the speed the train is seen coming out of the inversion in this video, I'm surprised it hasn't stalled more.



As other people have said. You would never expect Nemesis to even appear as though it was going to stall - even when empty and running in sub zero temperatures. Is there just a massive design flaw in this ride?

 

[Danny]

Just watching a video on YouTube of the ride testing (assume from prior to opening). The speed at which the train comes out of Batwing really is slow. I haven't been on the ride myself - was anything done to improve this after ride opening? Clearly it has stalled in the past but at the speed the train is seen coming out of the inversion in this video, I'm surprised it hasn't stalled more.



As other people have said. You would never expect Nemesis to even appear as though it was going to stall - even when empty and running in sub zero temperatures. Is there just a massive design flaw in this ride?

The reason it's running so slow is probably due to the ride not being fully worn in at that point, but also due to how slow the train ascends the first lift hill. It's noticeably slower than it is when open, and this is most certainly a contributing factor to the speed on the layout in that video.

 

[AirFAN]

The reason it's running so slow is probably due to the ride not being fully worn in at that point, but also due to how slow the train ascends the first lift hill. It's noticeably slower than it is when open, and this is most certainly a contributing factor to the speed on the layout in that video.

Sorry if it's a stupid question but can you define 'fully worn in'.

 

[Pepper_Plant]

Are there any images of the damaged carriage once the people were evacuated? What was the pattern of damage - was it uniform across the whole of the front area or were certain areas weaker?

 

[GaryH]

When I visited the park a few weeks ago the ride was running that slow. I recall commenting to my friend that it was just about making it through the inversions. Reminded me of one of those rides you build in RCT and the find it doesnt make it all the way around. I think there was definitely a slight miscalculation somewhere with the design.

Anyway, back on the subject of compensation, according to the Daily Fail, they could pay out milllions:

http://www.dailymail.co.uk/news/art...Towers-rollercoaster-crash-leg-amputated.html

Their lawer was on Radio 5 live today as I was driving home. He said that Alton Towers are making all the "right noises" at the moment in terms of accepting liability. He didnt want to say how much they could get, but said it would definitely be six figure sums. Also, I didnt know this but:

- Alton Towers have hand delivered letters to all 16 riders accepting liability
- Have contacted a private company specialising in rehabilitation after accidents like this (loss of limbs) and instructed them, if required, to work with the girl and others on the front row to assist them in any way they need.

However, as the lawyer also said, ultimately, the court case will be between Alton's insurer's and the lawyers, so who knows how it will play out. One things for sure, their policy is going up in price upon renewal!

 

[delta79]

@Pepper_Plant i have not seen any photos of after the event, however any photo would not show the orginal damage. As the fire service would of used equipment to free riders.

Also the two train contacted on a left had curve so more damage would of happened to the left front section of second train.

 

[Pepper_Plant]

@delta79 Thanks, that's good point.

 

[Alastair]

Decent piece on the incident on 5 Live last night, with an interview with Ned Hansen (founded Ride Centerline along with Alan Schilke). Starts at about 36 minutes in.

http://www.bbc.co.uk/programmes/b05xqb27

Sorry if it's a stupid question but can you define 'fully worn in'.

When we saw the first few test runs on The Smiler, they were very fast and it looked amazing. A day later, and it was suddenly running very slowly, almost stalling as seen on the video. I'm pretty sure it was down to wheel compounds, the TPW video above shows the train running brand new wheels, to test the limits of the coaster (and it was very close to the stalling limit there).

 

[Dave]

Dave, do you know for a fact that the HSE knew it stalled? Because unless somebody told them about the stalls, they probably wouldn't know about them - there is nothing in the reporting regulations RIDDOR that would require them to tell the HSE.

You are right in that the fact that a coaster stalls is not necessarily a major concern in itself. But when you design safety instrumented systems, you normally need to make assumptions about how often such safety systems will be required to operate - the so called 'demand rate'. Then, once you know the demand rate, you can work out how reliable the safety systems need to be to give a required safety integrity level. One thing the HSE will probe is what the design 'demand rate' for the ride was in terms of stalling - if it has stalled more often than anticipated, then there is a higher chance that any other safety systems may be deficient.

Way back in this thread, somebody mentioned the Swiss cheese model. You can think of the ride stalling as being the first layer in the swiss cheese - if it didn't stall, there couldn't have been an accident. The more often the ride stalls, the more 'holes' are in the first layer of the swiss cheese, and you need more rigorous safety levels in your remaining layers of cheese -or less holes - so that the gaps don't all line up. I suspect that is what has ben going on the previous few days - beefing up those other 'layers' so that they have less holes.

The first stall occurred during ADIPS testing, so they would have to be fairly blind not to notice. The block system on most coasters engages most days, even B&M are prone to "phantom trains" where the ride detects a train that doesn't exist so most manufacturers make the block system very robust.

The other thing to bear in mind is the mechanisms for stopping the ride if a block isn't clear on The Smiler are mechanisms that are operating anyway (lift hills, brakes) as part of normal operations, so what you don't want to fail is the system monitoring, but that shouldn't fail, stall or not as again it forms part of daily operations.

 

[AstroDan]

It is devastating to hear about the girl.

 

[EuroSatch]

I don't understand why people are defending the Smiler in relation to it stalling. Yes, it's a common occurrence on roller coasters, BUT they are theoretically designed to NOT stall. So yes, it was a design flaw.

Yes, it had been a while since stalling, and steps had been taken to reduce the chances of stalling, but given that the batwing is the location of every single stall since construction completed, it WAS a design flaw.

BUT it was not this design flaw that caused the crash, but a failure of the block system

 

[Nemesis94]

All rollercoasters have the potential to stall. Riddler's Revenege at SFMM stalled at the beginning of the season once, and earlier this year The Incredible Hulk at IoA had an incident (so B&M aren't immune to problems):
http://www.wptv.com/news/state/riders-rescued-from-stuck-hulk-roller-coaster-at-universal-orlando

A bird could fly in to a wheel, plastic/paper bag blow up in to the track or a wheel tyre burst. Any similar incident could jam the wheelset and bring the train to a halt mid-circuit.

 

[MichelinMan]

The first stall occurred during ADIPS testing, so they would have to be fairly blind not to notice. The block system on most coasters engages most days, even B&M are prone to "phantom trains" where the ride detects a train that doesn't exist so most manufacturers make the block system very robust.

The other thing to bear in mind is the mechanisms for stopping the ride if a block isn't clear on The Smiler are mechanisms that are operating anyway (lift hills, brakes) as part of normal operations, so what you don't want to fail is the system monitoring, but that shouldn't fail, stall or not as again it forms part of daily operations.

But would the HSE be present during ADIPS testing (whatever that is - sorry, don't know what the terminology is!)? I would be very surprised if that was the case - please correct me if I'm wrong, and you know something definite, but I would think their presence would be very unlikely.

HSE doesn't need to witness tests and give approval for operation (in fact they positively stay away from such things - they never want to be seen to be part of any QA process - and it is because of situations like this where people can turn around and say 'you were there when we tested it and you never raised any issues then'). Furthermore, the HSE just doesn't have the resources, especially nowadays, to do much more than incident investigations outside of major hazards sites like chemical plants and offshore. Despite what the general public think, there isn't an army of HSE inspectors with clipboards waiting to pounce.