Discussion in 'General Discussion' started by Matt N, 1st May 2021.
It DID work for 11 seasons, then it didn't. So it's notable and needs to be fixed
Right, but you're dealing with an exception, not a fundamental flaw.
So are we saying that well maintained, wet weather tyres of a high quality won't sort the issue out then?
I think the fact the ride has operated for over a decade without any issue, the fact Intamin currently have several drive tire lift hill rides in operation with no major issues, and the fact is has only recently started happening in the wet, pretty clearly suggest this is not some sort of inherent design flaw. The two words ware and tare spring to mind. I would suspect ware on the fins and the tires could be contributing factors in this. Also, it is well known within theme park engineering that there is always an increased risk of having roll backs on drive tire lift hill rides, in the wet, from all manufactures. This is not a problem that only Intamin have faced!
I would suspect a total refurbishment of the complete traction system will be carried out over the closed season as a minimum. This will bring the traction system back to nearly new quality, this should sort the issue, after all it worked fine for a decade. So no reason why it should not now. When I mean traction system I also mean the fins on the trains.
I do not think enclosing the lift hill would help, it will keep the lift hill dry for a while, but the trains cycle through the ride constantly, the fins on the trains would be picking up moisture form the rest of the drive tires on the circuit of which there is many. It would not be long before the wheels under the enclosed section would be damp, and even soaked again on a very wet day. You can see this in action just by looking at the soaking wet drive tires in a ride station on a wet day. Exactly the same.
Another solution, but not sure how feasible it would be to retro fit onto Thirteen, would be to use one of the newer generation anti rollback systems. One that first appeared on Expedition Everest, but is now commonly used among a few manufacturers. The movement of the train turns a cylinder with a mechanism inside that contracts due to the centrifugal forces placed on it by the moving train. This lifts the anti roll back dog up clean off the track, giving a completely silent accent as if there was no anti roll back device. When the train slows / stops, the forces stop upon the cylinder, dropping the dog in place and locking the train to the lift. It sounds a lot more complex than they are, the engineering has been refined over the last 15 years to the point they are relatively cheap to implement. The question is, is there room to retro fit this to the ride, and would Alton want to spend the money. It would require modifications to the track and the trains. But this is a solution that would tick all the box's, a guaranteed train arrest that would prevent any rollback and totally silent operation keeping the locals happy.
It’s almost certainly down to a shortage of maintenance staff, they are obviously just doing the bare minimum to get rides open safely. So bigger tasks such as replacing all the tyres on Thirteen and getting all the guns working on Duel seem to have been pushed back to the closed season.
@DistortAMG That anti rollback has a known issue on wet days. the wheel sometimes doesn't grip so so you end up with the normal life hill noise, but worse since they don't fit any noise dampening to the tooth. (reference YouTube - Art Of Engineering - 2019 Nov 29 - Why Roller Coasters Click).
From my memory so take with pinch of salt since I can't remember the document location. During the Pandemic to save money the Merlin group mention reduced maintenance as well as wage reduction as ways of saving money. They did state safety would not be put at risk.
@DistortAMG raises a good point; Intamin have many other coasters with the same drive tire lift hill system that have been operating fine for years. For instance, Mine Train Ulven at Bakken was built in 1997 and has had no major problems with it, and I think many of Intamin’s family coasters dating back as early as the mid 80s to early 90s utilised a similar drive tire lift system. No issues have been reported on any of those as far as I’m aware.
That leads me to believe that it’s more likely to be an isolated issue with Thirteen, and one that’s only cropped up fairly recently. Is it wear and tear like some have suggested above, and if it’s not, I wonder what the problem might be?
Sorry to ask, but what is this rollback incident that everybody is speaking of? I can’t seem to find any reference to it on this discussion or elsewhere. Did one of the trains slip down the lift in the rain and re-enter the station backwards?
Yes, a train slipped down the lift in heavy rain as the tyres were too wet.
Fascinating video! Although the mechanism I am referring too is totally different to the silent one mentioned in that video, which to be fair, looks like a rather bad design, as yes it does appear like it could slip.
The modern alternatives can work under water they are so robust. They rely purely on the physics of mass and are totally unaffected by water of varying amounts. Centrifugal force is always going to be centrifugal force, doesn't matter if you are on a mountain or under the sea, the physics will work the same.
I am not sure if the design in that video is totally accurate to the modern types, there are a few key changes that make them much more reliable and robust than what is shown in that video. One of the key differences is having weights inside the cylinder, spring loaded and will push outwards when the train is in motion, pulling the dog chain upwards via a simple lever mechanism. Very simple and very effective, not much to go wrong, so are very very reliable. Unlike in that video, the cylinder is not being relied on to grip anything, just been used for the physics being placed upon it's inside when in motion, there is nothing to grip, so nothing to slip, ever. No matter how wet. The wheel in that video gets it's motion from literally gripping onto the track, so yeah it could slip on wet days. The design I have seen, get's its motion directly from the vehicles axel, pretty much built into it. So does not grip anything, guaranteeing it to spin as long as the axel did. If the axel was not spinning, the train would be out of service. So very robust.
Always guaranteed to work regardless of conditions. As is common for coasters, based off technology build for a different industry.
Ah, fascinating. Slight off topic, but have to got any reference material videos/diagrams/design docs etc? I would say PM me, but don't think u can on this forum. I'm truly interested in the mechanical/engineering side of attractions.
I will have a look, I am sure I have some documents somewhere. I am sure the device I mentioned uses the lovely magic of eddy currents to aide the movement of the weights inside the cylinder too. I should be able to PM you once I have found them. I can post them here though, do not mind.
Probably in my garage, I have a fair few engineering, SOP's and maintenance guidelines from manufactures for a fair few ride types, I am sure the details will be in there.
As discussed the tyres either aren’t suitable for autumn weather or they have worn down and not been replaced. This is almost certainly due to a lack of maintenance staff to do the work.
Just to clarify and clear a misconception, I have been told by a reliable source that the train that slipped off the lift did NOT roll back into the station or make contact with another train. It just travelled the wrong direction on the lift hill.
Not sure how reliable your contact is. Alton Towers themselves confirmed it did make contact with another train:
‘A spokesman said: "During the routine operation of TH13TEEN on Thursday, September 9, we can confirm that one of the trains made soft contact, at low speed, with another empty carriage in the station.
"All guests were spoken to by our team and left the station as normal. The health and safety of our guests is our top priority and the ride is open as normal after thorough safety checks were successfully completed."
I very much doubt they would publicly confirm this did happen if it wasn’t the case.
That is an article about a low speed collision that took place back in September. From what I understand from various staff members, the roll back took place early October, a few days before the start of Scarefest and the trains were empty and did not make it back to the station or collided.
I may of been misinformed, but the above article doesn't mention any form of roll back, just a soft collision which you wouldn't get from a roll back.
There is no way that the park would mention roll backs or the word collision etc, it will have been carefully crafted to minimise the incident without straying into lying about what happened. They had to mention the contact between trains because a few guests had already mentioned witnessing it on social media, so the cat was out of the bag so to speak.
These accounts on social media were initially rubbished (the accounts stated the train rolled off the lift back towards the station and hit the train in the station) - however the ride was then closed for a few days and the article published and the statement was released by Alton Towers corroborating those accounts.
Of course it is entirely possible that another incident occurred after this, linked to the same issue which did not result in a train hitting another one, but operations certainly changed after the Sep incident, it was a pretty dry month weather wise, so it perhaps wasn’t too evident as it didn’t have to close that often.
It is entirely possible that there was another rollback with guests not on-board, but something did take place in September which caused several Tweets (see https://towersstreet.com/talk/threads/thirteen-general-discussion.5757/page-5#post-337508) and the response by AT linked above.
I believe you that something occurred in October as,well, but if was with empty trains with no guests seeing it happen then it wouldn’t have been discussed as much as the September incident that was reported on Twitter and responded to by AT in the Sentinel article above. It’s very possible both occurrences happened.
This is interesting, watcing a POV and noticed that there are two different types of wheels/tyres on the lift hill;
Was this always the case? It looks different to me.
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