Incident on The Smiler 02/06/2015

[jon81uk]

No offence to those who commented, but there are a few inaccuracies about how rollercoasters work being discussed.

@phildenholm Increasing the lift hill speed will just get the train to the top faster, it bears no relation to the speed of the train on the track. Think of a marble run, if you place a marble at the top it will roll down, if it encounters a hill it doesn't have the momentum to get up then it stalls, it doesn't matter how fast you push the marble to the top of the hill it will still roll down a the same speed.

@Nemesis94 all good reasons why a stall could happen, except the burst tyre, I am not aware of any coaster with inflatable wheels, they are solid plastic or rubber usually (different compounds of plastic give different speed).

I am no expert so I am sure there are engineers that know a lot more!http://www.towersstreet.com/talk/members/phildenholm.1830/

 

[Dave]

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.

ADIPS safety test amusement rides, they are not part of the HSE but they work under their accreditation. All Rides get ADIPS check before their opened and annually.

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

No one is defending the ride stalling, it shows how shoddy the design was. That said people are fixating on the stall when to me the worrying feature is the block failure, because block rules should be absolute on all coasters. Stalls happen around the world all the time (Most never get reported), we therefore need to be sure the block system can be trusted.

 

[Rob]

Indeed, HSE are very limited in their resources now. I was only speaking to someone about this at work the other day (I work in business regaultion) and in theory HSE, as the UK's national H&S body, are meant to audit out public safety department. However this does not happen, they do not have the resources. The vast majority of their time is spent on incident investigations which take up a lot of time. Taking something to court is a very lengthy process.

Anyway, regarding the stall, I think it is wrong to say that the stall is irrelevant. The stall was not the main cause of the incident, however it was very relevent to what did happen. If there was no stall there would have been no crash. The main cause was the block failure and why a train was allowed to be sent over the lift with the train ahead not clearing the block.

Now stalls can happen on any coaster, of course you don't want them to but it's just one of those things. The point here though is that The Smiler has a history of stalling, far more so than other coasters. This was either the third or fourth time it had stalled at this point. I believe this is the first time it has stalled during 'normal operation' though (i.e. not in testing/morning testing).

So with the ride laible to stalling, I would imagine one of the many things that the HSE will look at is what measures are in place for if a train does stall, especially if it was to happen with the ride open to the public. It appears that the stalled train was not identified by the ride system or staff (although the ride system clearly had initally worked out that the train had not cleared the block). I fully expect Towers to add proxy sensors to the batwing so that if a train does stall in the future the train will be detected by the ride system, even if the whole system is fully reset to 'clear' the blocks. There will also be a camera added looking directly at that part of the track I would imagine, seeing as there doesn't seem to be at present. Both of these modifications should, in theory, mitigate against a similar incident.

As I say though, the HSE will be thorough and look into everything. This will just be one of many parts of the investigation.

 

[Dave]

There are coasters out there that beat Smilers stall rate. The stall as said is relevant in the chain of events but its the block failure that worries me. Stalls are an accepted risk of coaster operation. Block failures should NEVER happen.

The incident at LWV that killed someone was a block failure allowing a car to crash into a stalled car and the failure was pinned down to errors in the block system. The stall was barely mentioned.

 

[Rob]

There are coasters out there that beat Smilers stall rate. The stall as said is relevant in the chain of events but its the block failure that worries me. Stalls are an accepted risk of coaster operation. Block failures should NEVER happen.

The incident at LWV that killed someone was a block failure allowing a car to crash into a stalled car and the failure was pinned down to errors in the block system. The stall was barely mentioned.

I agree, but as we know the block system did it's job initially in stopping the train at the top of lift 1. It was there for at least 5 minutes. If the ride randomly restarted itself then there was something very badly wrong with the block system. Now I assume all blocks can be manually reset, otherwise a coaster would never get going again after a stall. If, and I do emphasises the if, something like this happened there would have been a clear failure by both the ride system and staff to identify a stalled train (as well as a procedural failure). If a stalled train had been identified you would imagine that the ride would immediately have been E-stopped, even after the block had done it's job, and a standard lift-evac would take place.

 

[TheBeast]

I think that was why the block brakes didn't stop them- they were overridden by the operators. I don't really know why though (and none of us do, obviously), as a whole carriage is quite hard to miss in all honesty. Its another weird coincidence we can only speculate about, if I am honest

 

[AirFAN]

How likely is it the park would be able to ensure the ride doesn't stall again? The media are likely to take more of an interest given the recent events if this was ever to occur - "Disaster ride stalls again". Even with a more robust block system in place the media are still likely to have a field day.

 

[PeteA]

I agree, but as we know the block system did it's job initially in stopping the train at the top of lift 1. It was there for at least 5 minutes. If the ride randomly restarted itself then there was something very badly wrong with the block system. Now I assume all blocks can be manually reset, otherwise a coaster would never get going again after a stall. If, and I do emphasises the if, something like this happened there would have been a clear failure by both the ride system and staff to identify a stalled train (as well as a procedural failure). If a stalled train had been identified you would imagine that the ride would immediately have been E-stopped, even after the block had done it's job, and a standard lift-evac would take place.

This is they key to all of this. It also speaks volumes that Gerstlauer multi car coaster are still continuing to operate outside of Merlin parks around the world.

 

[AirFAN]

I also find it bizarre the media hasn't mentioned the manufacturer in any of their reports. Why isn't Sky (for example) inviting Gerst on for an interview?

 

[Rick]

@phildenholm Increasing the lift hill speed will just get the train to the top faster, it bears no relation to the speed of the train on the track. Think of a marble run, if you place a marble at the top it will roll down, if it encounters a hill it doesn't have the momentum to get up then it stalls, it doesn't matter how fast you push the marble to the top of the hill it will still roll down a the same speed.

It's not so much about the speed it climbs the lift hill, it's about the speed at which it begins it descent (which is more often than not the same). Take an Intamin coaster with a cable lift like Goliath or Millennium Force, you crest the lift hill three or four times faster than you do than on most coasters with a traditional chain lift.

If the train 'departs' the lift and goes into freefall at 20mph (like the above), rather than 5mph - the speed at which the train is travelling at the base of the first hill is faster, no? Someone get their Hot Wheels cars out, we'll check.

@Nemesis94 all good reasons why a stall could happen, except the burst tyre, I am not aware of any coaster with inflatable wheels, they are solid plastic or rubber usually (different compounds of plastic give different speed).

S&S built a couple of coasters with pneumatic tyres, for reasons I am not sure they are willing to talk about now. Hypersonic used them and maybe Dodonpa too? Not sure, didn't look.

I also find it bizarre the media hasn't mentioned the manufacturer in any of their reports. Why isn't Sky (for example) inviting Gerst on for an interview?

The same reason they don't invite Porsche or Lambo on when a celebrity wraps one around a lamp post in Hollywood.

 

[Dave]

I agree, but as we know the block system did it's job initially in stopping the train at the top of lift 1. It was there for at least 5 minutes. If the ride randomly restarted itself then there was something very badly wrong with the block system. Now I assume all blocks can be manually reset, otherwise a coaster would never get going again after a stall. If, and I do emphasises the if, something like this happened there would have been a clear failure by both the ride system and staff to identify a stalled train (as well as a procedural failure). If a stalled train had been identified you would imagine that the ride would immediately have been E-stopped, even after the block had done it's job, and a standard lift-evac would take place.

That is obviously the other potential cause, I doubt operators can override the block system (they can't on other coasters) but tech services probably can.

Im uneasy delving too much into the human error side of things what with the press attention and peoples feelings so soon after though so will leave that well alone.

 

[Rob]

How likely is it the park would be able to ensure the ride doesn't stall again? The media are likely to take more of an interest given the recent events if this was ever to occur - "Disaster ride stalls again". Even with a more robust block system in place the media are still likely to have a field day.

You make a good point, if it does stall again and any of the public catch on (or even us for that matter) the tabloids will be all over it, even if it is a fairly 'normal' thing to happen. The main reason for the stalling on The Smiler is design flaw, only re-profiling would help aid this. I can't see it being re-profiled though.

Anyway, here is the latest statement from Merlin in full:

"Since the accident of last Tuesday we have done our best to provide appropriate communication and support to those involved and to their families.

"We absolutely recognise what a difficult time this is for everyone, especially those who have been so seriously injured, and we have tried to do this in a way that is both sensitive and appropriate.

"Over the course of the weekend we have written again to all of the 16 people involved or to their families. These letters were all hand delivered by Alton Towers representatives.

"Irrespective of the outcome of the current investigations into the causes of the accident, in these letters we have accepted full responsibility to those who had been injured in the accident and confirmed that we will ensure that compensation will be provided to them.

"We have recommended each of the injured guests or their families instruct a lawyer and submit a claim for compensation which we will ensure is dealt with swiftly and sensitively.

"In addition we have engaged the services of Health and Case Management Ltd (HCML) – a leading firm of specialist independent rehabilitation providers - to provide all of those involved with the best support for their individual needs whether from the NHS or by providing additional support and services.

"HCML have already made contact with some of those affected in order to progress this."

 

[Alexsutton]

Although the stall itself wasn't the critical fault here, others have raised the interesting point that if The Smiler stalls again in operation it does seem pretty likely to cause panic and bad press after this incident, even if the system and staff react to the stall appropriately. I wonder if that is something they will consider once the cause of this accident is resolved.

 

[Dave]

Although the stall itself wasn't the critical fault here, others have raised the interesting point that if The Smiler stalls again in operation it does seem pretty likely to cause panic and bad press after this incident, even if the system and staff react to the stall appropriately. I wonder if that is something they will consider once the cause of this accident is resolved.

Purely from a quality point of view I wish they had reprofiled 3 parts of the Smiler. The stall point and the two big jolts, guess it isn't a cheap job though and if you trusted your safety systems not top priority.

They may re-explore the options now though I guess.

 

[Slugjc]

Merlin have done the first step into major damage limitation, and lets face it this is a good thing. To actually send someone to deliver the letter. Great touch. It gives the person involved a human touch that is always lacking these days. However I would not like the job of giving the letter. The people involved, even if they wanted to see them or not, they now have a face to relate to merlin with. Now all that's left is to see how the families react.

 

[Rob]

Towers was said to be very quiet yesterday. Well it looks like today is even more dead; the only attraction reporting a queue on ridetimes is Mr Bloom's Allotment (10 mins). Everything else is a 0 min wait.

 

[Rick]

Towers was said to be very quiet yesterday. Well it looks like today is even more dead; the only attraction reporting a queue on ridetimes is Mr Bloom's Allotment (10 mins). Everything else is a 0 min wait.

I guess it will take a little time for it to become clear why it is so quiet, it could be for a multitude of reasons but amongst the key ones I suspect it will be along the lines of:

1. General apprehension about visiting after the accident – completely understandable, of course
2. An understanding of the fact that half the rides on the ‘Thrill’ tab of Ride Times are closed and people will wait for them to reopen
3. Finally – the fact the park was closed until Sunday and yesterday was the first ‘working day’ where people could make the decision as to whether to book the day off or not, will play a part.

 

[phildenholm]

Purely from a quality point of view I wish they had reprofiled 3 parts of the Smiler. The stall point and the two big jolts, guess it isn't a cheap job though and if you trusted your safety systems not top priority.

They may re-explore the options now though I guess.

I guess now its going to be closed for far longer than normally possible it might happen. I accept your point about stalling on track being a fairly regular event but I do think something needs to be done to reduce the likely hood of this happening, as its been pointed out Nemesis has never and will likely never stall.

Regards the speed of the hill lift not changing anything I disagree, as someone else has already pointed out if the car enters the area doing 20 mph rather than 5 mph it is far less likely to stall on track.

Nice to see Merlin are still doing a good job of looking after the 16 guests, I guess this is so far the one good thing to come out of this tragic incident

 

[jon81uk]

Regards the speed of the hill lift not changing anything I disagree, as someone else has already pointed out if the car enters the area doing 20 mph rather than 5 mph it is far less likely to stall on track.

The speed of the lift hill doesn't determine the speed the car will travel on the track. Gravity and potential energy do, all the lift hill does is get it to the top of the hill. Think of Oblivion, if I speed up the lift hill, will the car drop quicker?

Launched coasters don't have lift hills such as the Incredible Hulk at IoA or Rita or Stealth, these are fired up the incline or along the track either by wheels or a cable at very high speed and therefore the start speed is based on the speed you are accelerated to by the launch, not the potential energy at the top of the drop.

So yes, you could replace the chain lift with a launch but then it is an entirely different type of coaster and it may affect the ride in other areas, such as needing more brakes or just being uncomfortable.

 

[Rob]

I have seen that yesterday on the coasters, trains were not being dispatched from the station until the other train had come to a stop in the final brakes. It appears this could be the extra level of safety, or it could be a temporary measure whilst the park is quiet.