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Accident at Alton Towers


Certified Ride Geek
I think there might be less people applying for that rollercoaster tester contest now. Such awkwardly bad timing considering that was their last publicity stunt.

Seconding the comments for good recoveries from hopefully not too major injuries.

Screaming Coasters

Strata Poster
Just to clear up the sensor thing..

Sensors on a roller coaster are very similar to that of commercial passenger trains. However, there are major differences that set them apart: Sensors on a roller coaster expect a count. Whether it comes from a wheel count or a carriage count, it expects a certain number to clear in a pre-programmed timeframe (usually a few seconds), before the computer recognises the train clear from a block. The sensor will not accept a singular passing, which is why a foreign object such as a bird or a leaf triggering the computer will not allow the PLC to accept an "all clear" blocking signal.

I find it extremely hard to believe some of the things said about the sensors that have been passed around. Knowing this fact, its highly unlikely that it has been triggered but a foreign object, which has been speculated on numerous forums and coverage.

I'd also rule out manual-operation. Its almost impossible for a regular operator to understand how to move a train in manual mode. I've done it when I had a go at engineering and boy let me tell you, its as complicated as hell. No regular operator will understand where to begin in manual mode. You have to understand the ride to its bare-bones to even get a wheel to fart. This is yet another speculation that has been passed around.

Without knowing anything on the forefront of this, I'm just throwing my 2 pence worth of experience.


CF Legend
As the only source at the moment that a leg has been lost is a staff member talking to the Daily Mail, take it with a heap of salt.

They've also said it stopped at the top of the inversion, which we know it didn't. Shame really, impact would have been less!


Hyper Poster
If what the Mail is saying is true, I can see the Smiler doing a Dragon Challenge and running with only one train. Either that, or it will be SBNO for ages, which would at least rectify any problems.....


CF Legend
The Mail who said it stopped at the top of a loop...

Has anyone mentioned how Saw had that crash as well? That didn't put anyone off.


Staff member
Thorpe's PR team probably would class that as part of the theme though Ben...

Terrible incident though and I wish the best for those hurt. I can't imagine anything worse than going to a theme park for a joyful day out and having this happen. It's dreadful - rare but dreadful.

I also can't imagine there's any way this is anything other than human error. I don't think for a second the ride ops have the ability to release trains onto the circuit if the system isn't showing as clear.

With the ride being stopped for several minutes with the train on the lift hill, it suggests that it was a standard stop situation. For that train to be released, somebody with the ability to override the system must have done so. It's happened before (LWV).

It could be computer error, but I just can't see it. This ride has regular stalls and it mustn't be an uncommon procedure the team go through. If there was a weakness in the programming of the system, this would have happened sooner. I just think that somebody has unfortunately made a mistake. It's tragic, but it does happen sadly :(


Hyper Poster
elephant58 said:
If what the Mail is saying is true, I can see the Smiler doing a Dragon Challenge and running with only one train.

This is a plausible possibility, either that or running with 2 trains but waiting until the train completely finishes the course before dispatching the next one.

Another (fairly expensive) idea to get people back on could be completely rebranding the ride with a different name and theme plus repainting it and giving it new trains. It can make people feel as if they're going on a completely different ride if its done right e.g. Rougarou. Terra Mitica is doing something similar by repainting their Zacspin of Death in an attempt to mitigate people's memory of it as a killer ride.

Check out this poll where readers decided whether or not The Smiler should be scrapped. 80% are in favour of yes.

Nemesis Inferno

Strata Poster
Hey look, people on the Daily Mail website are over-reacting to something, isn't that a thing?

Bearing in mind that this is the image they posted, and their readership tend to be insanely idiotic at the best of times:



Mega Poster
That's the only mention of inversions in the whole article. The rest of the page is plagued with loop de loops.

Interesting to see if we ever find out the true cause, either way it'll be damaging for AT or Gerst!


Mega Poster
So according to infograpihic from Daily Mail second train stopped on inversion hanging upside down ? Is it possible ?


Strata Poster
I mean the only way it's remotely possible in my head is if they realised the mistake in restarting the lift where we know for a fact it had stopped when the empty train had valleyed, and the brakes it has to go through to get to the batwing slowed it enough for it to only just make it round the inversion before stalling itself upside down.

But that's far less likely than the Daily Mail are just being thick as usual.


Hyper Poster
It does amaze me how most of the general public and media don't seem to realise that rollercoasters are gravity powered and once they get moving, there is no control to stop them mid track!

I think Pokemaniac's comments on page 7 of this topic best sum up the most plausible explanation so far. The computer system only has an artificial knowledge of where the trains are based on detecting movement on sensors at the start and end block segments. A computer can recognise that a train has entered a block and will mark that block as occupied until it detects a train leaving - they likely have no way of telling where abouts in the block the train actually is.

If a reboot was to happen with a train stalled, it is likely the blocks mid track would be marked as clear and the system relying on the operators to be aware of any mishap and ensuring the track is clear before starting the ride. Engineering would have been present in the control booth, given the breakdown that was occurring, so it is highly likely that someone with the skills and authorisation to reboot or manually control the ride were present.

As for the empty car stalling in the first place, sending empty trains after a breakdown is very common, especially mid afternoon when the ride is probably running at optimum temperatures. I believe all other stall events on Smiler have happened first thing in the morning? Its impractical to load and unload water dummies for every minor breakdown the ride has. However, yesterday was very windy and you only had to look at the umbrellas around Oblivion on the TV shots to see just how bad it was. I suspect this just added to the bad luck Alton was having yesterday afternoon!

To me it seems like a combined failure of human error and a limitations of the computers knowledge, causing the holes of the swiss cheese to line up and an accident to occur.

As always with an accident like this the focus of the investigation will be how to prevent it happening again. If the above theory turns out to be correct, I suspect we can see an overhaul behind the scenes of computers systems and sensors, perhaps with some new technology so computers can always keep track of a car no matter where it is in a circuit, but otherwise no major changes visible to the outside public and we'll see the ride re-open as soon as Alton can.
There's likely some extensive damage to the 2 trains involved, from the collision and extraction process, so perhaps a complete new set of trains will be required. The more modern Gerstlauer trains have favoured clamshell restrains which would be an improvment on the smiler, but I suspect they would have to make a big deal of adding more safety features than removing OTSRs.


Goon of the Year
I had a chat with Aaron about this earlier for my channel.


Martyn B

CF Legend
Typical overreaction on the front page of the Sun today, COASTER CARNAGE!!!!!!

I wonder if there's a 2 for 1 voucher inside? ;)


Staff member
Peter: my issue with Poke's theory is that if there was a power reset halfway through an e-stop, with cars cycling - then the minimum the staff should be doing is a simple train count - Where are those trains physically? We've all seen how often empty trains are cycled after any breakdown, usually every train on the track is sent through before riders are allowed on. The ride was stopped for several minutes, are we really saying nobody noticed the stalled train? Really???

Sent from my D6603 using Tapatalk


Hyper Poster
I completely agree Furie, someone must have noticed it had stalled after that amount of time, but with basic knowledge of the systems at play here, its the best and most plausible scenario at the moment and a way to cheat the computer system to allow 2 trains in the same block segment.

If a ride is restarted, is it possible that the lift hill will automatically start up and the train sent by accident? I would really hope not, but a misunderstanding by the engineers on how the ride will respond to a reboot is always an option.

Another theory (throwing them out here now!) could be that Smiler is unique in that it doesn't have anti-rollbacks meaning the trains can be rolled backwards down the lift hill in the event of an evacuation. We've seen this happen in the past and may well be something they were trying to do with people stuck at the top for 15 mins and the knowledge that a car had stalled so an evacuation was inevitable. You then ask the question of if its possible to manually reverse the train, can you also send it forward over the top of the lift by accident? I doubt anyone here will know unless you're a Smiler engineer! :wink:

Lots of theories and I hope they can find a good explanation as to why two trains ended up in the same block as they've managed to break the primary rule of rollercoaster safety!