Goliath blows a wheel

[Xzentrificenceo]

For a very good source I have(he was on the train at the time) Goliath at SFMM blew wheel yesterday. He said that is happened at teh bottom of the first drop. There was a load bang and it was not until they reach the turnaround at the top of the hill that they saw smoke and parts of the Polly wheel flying throught the air. The train did make it back to the station safely, and NO BODY was injured. I have not found any thing about it on the SFMM site nor do I expect to. But this source is very credible.

Six Flags needs to work out their problems and get the rides to be safer!

[IEATPASTE001]

Mountain Jumper will be pleased. lol

[Xzentrificenceo]

The way it sounds this was not anything that was avoidable. Lets not forget that these are machines and they do break at the most inconvienent times. This happened after the daily inspections so it was just an accident.

[IEATPASTE001]

Corkscrew burned a wheel off or a few one day, it was rather hot and running way too fast! it happens everywhere.

[Harpo]

Yes, it can happen anywhere. However, in most cases, there are enough wheels that one bad wheel would be insignificant. The question I would have to ask, and that I know you couldn't answer, would be this: Were the sensors indicating a vibration issue in the wheels prior to the blown wheel? The reason for this question: If the sensors already sensed a bad wheel, either being the one that blew or one nearby, ignoring the bad wheel adds to the chances of a major failure, and increases wear on the remaining good wheels.

Parks are not all consistent on how they deal with the bad wheels. It's actually one of the reasons Cedar Point's coasters have a chance of being shut down briefly on any given day. When the sensors indicate a bad wheel, maintenance is immediately called, the ride is stopped, and the wheel is replaced. I know that there are parks that will ignore the bad wheel until the end of the day, figuring that there is enough redundancy in the ride to compensate for a bad wheel or two.

I don't know Magic Mountain's policy on it, hence I cannot make judgements about this situation. It may or may not have been unavoidable, dependent on their policies and what sort of warnings they had. I do know that I've been on rides at various parks (including some Six Flags parks) where it was possible to actually feel that some wheels were bad, yet they were allowing the ride to keep running.

Do you happen to know Magic Mountain's maintenance policy relating to vibration sensors indicating a single bad wheel?

[Xzentrificenceo]

No I don't know what their policy on that is. I can see if I can find out.

[IEATPASTE001]

My question is, did it hurt the track, that is my main concern besides, why did it happen and what can be done to prevent it. I hope OSHA doesn't condem it before i get to ride it! i know OSHA can be rather strict.

[Harpo]

Probably provided a slightly bumpier ride. However, in the eyes of Six Flags, that would be a good thing. Based on my experiences at so many of their parks, I believe they equate bumpy with exciting.

(I should hasten to mention that Goliath was a rather smooth ride. I liked that coaster, although my favorite of the Magic Mountain coasters was Viper.)

[IronWolf98]

Originally posted by Harpo
Yes, it can happen anywhere. However, in most cases, there are enough wheels that one bad wheel would be insignificant. The question I would have to ask, and that I know you couldn't answer, would be this: Were the sensors indicating a vibration issue in the wheels prior to the blown wheel? The reason for this question: If the sensors already sensed a bad wheel, either being the one that blew or one nearby, ignoring the bad wheel adds to the chances of a major failure, and increases wear on the remaining good wheels.

Parks are not all consistent on how they deal with the bad wheels. It's actually one of the reasons Cedar Point's coasters have a chance of being shut down briefly on any given day. When the sensors indicate a bad wheel, maintenance is immediately called, the ride is stopped, and the wheel is replaced. I know that there are parks that will ignore the bad wheel until the end of the day, figuring that there is enough redundancy in the ride to compensate for a bad wheel or two.

I don't know Magic Mountain's policy on it, hence I cannot make judgements about this situation. It may or may not have been unavoidable, dependent on their policies and what sort of warnings they had. I do know that I've been on rides at various parks (including some Six Flags parks) where it was possible to actually feel that some wheels were bad, yet they were allowing the ride to keep running.

Do you happen to know Magic Mountain's maintenance policy relating to vibration sensors indicating a single bad wheel?

Sensors??? For bad wheels?? Of the four years I worked at Six Flags, no where in any of the ride manuals was there ever any mention of wheel vibration sensors. Most all unusual noises and vibrations are sensed by the guests and employees. There are proximity switches and photo eyes that relay info on the train which allows the computer to calculate the ride's speed. However, unless the ride is overspeeding, the ride doesn't normally shut down. Once an operator reports to maintenance that the ride is "running smoothly", then it is a maintenance decision whether or not the problem is serious to remove the train from operation.

[Harpo]

Well, I'm not sure what was in your manual, and maybe Six Flags opted not to install them, but Cedar Point's coasters have had vibration sensors for years. They determine unusual vibrations registered by the wheels. I'm not sure about newer systems, but I know the older ones (from when I worked at Cedar Point in the late '80's) could only pinpoint the train, and which side of the train. It could not pinpoint which wheel set. So, when the sensors would trigger, maintenance would have to perform an inspection to determine which wheel was bad. They would replace the suspect wheel and re-run the train. If the sensors still triggered, they'd check for another bad wheel. The process is repeated until the sensors pass the train.

I do not know the exact placement of these sensors, nor how many there are. But, from my discussions with some of the Cedar Point maintenance people, they apparently are quite effective at providing early detection of faulty wheels.

[IronWolf98]

Originally posted by Harpo
Well, I'm not sure what was in your manual, and maybe Six Flags opted not to install them, but Cedar Point's coasters have had vibration sensors for years. They determine unusual vibrations registered by the wheels. I'm not sure about newer systems, but I know the older ones (from when I worked at Cedar Point in the late '80's) could only pinpoint the train, and which side of the train. It could not pinpoint which wheel set. So, when the sensors would trigger, maintenance would have to perform an inspection to determine which wheel was bad. They would replace the suspect wheel and re-run the train. If the sensors still triggered, they'd check for another bad wheel. The process is repeated until the sensors pass the train.

I do not know the exact placement of these sensors, nor how many there are. But, from my discussions with some of the Cedar Point maintenance people, they apparently are quite effective at providing early detection of faulty wheels.

I suppose it is possible that the prox switches can detect it, but highly unlikely. The most they do is monitor where the trains are and how fast they are going, so I suppose you could stretch that to mean if a wheel is loose then it would be detected. But we never had a trouble light for a slow train, only fast trains. That was my job responsibility to know if the ride was operating properly. And since I trained people on those rides, I think I'm in a good position to say if something is in the ride manual or not. Did you work in maintenance? Perhaps the maintenance guys were pulling your leg about wheel sensors? I can't imagine why only one park would install them and not another. I'll do a patent check for them and see what turns up.

[Harpo]

No, it definitely wasn't the proximity sensors. And, I knew those maintenance guys too well -- I know they were giving me good info. No, I didn't work in maintenance. I was in the games department. But, I knew maintenance folks, and ride ops, and people from every department in the park. After all, we all lived in the same dormitories together. (Cedar Point has employee dorms -- most amusement parks do not have such a thing. Cedar Point's first dorms were built back in 1906.)

Why wouldn't all parks install them? Could be money. I don't know how much such items would cost.

Do such things exist? Absolutely. As an electrical engineer, I've had to interface with such items in the automotive industry. They've been around a long time, although I couldn't tell you how long. (I believe Allen-Bradley made the sensors I've dealt with in the past. Many coaster sensors also tend to be A-B products, although I'm sure there are other manufacturers who are used, as well.)

How does the warning show up on the roller coaster control panel? I have no idea. I've not worked on the control panels. For all I know, it could show up as a general safety shutdown, leaving it up to the maintenance folks to figure out the reason. I just don't know for sure -- I never asked.

I can tell you for certain that not all coasters are equal in their sensors. For example, X at Magic Mountain does not have a locked harness sensor. When I rode it, the harness next to me (on an empty seat) was wide open, and the ride continued as normal. On Corkscrew at Cedar Point, I've watched the unlocked harness tests. The lift shuts down if train reaches the lift with any harnesses unlocked. Those coasters were even made by the same manufacturer (Arrow), yet they have different sensors.

[Xzentrificenceo]

I know that Riddlers has some serious sencors on it. One train I was on was stopped part way up the lift hill because a belt buckle was undone. They came right to the kid next to me and rechecked his as it came undone after teh harness check. He was goofing around with it and it opened.

[IronWolf98]

Originally posted by Xzentrificenceo
I know that Riddlers has some serious sencors on it. One train I was on was stopped part way up the lift hill because a belt buckle was undone. They came right to the kid next to me and rechecked his as it came undone after teh harness check. He was goofing around with it and it opened.

That could be a camera...BTR at SFGrAm has cameras on the lift so the ride ops can detect unlocked seat belts. I know the more recent B&Ms tend to be more sophisticated with restraint detection. Most older coasters aren't.

[Xzentrificenceo]

No not a camera because you could not see that it was unbuckled, as he was barely tall enough for the ride mabye 56" and he was on the inside of the train.

[IronWolf98]

Originally posted by Xzentrificenceo
No not a camera because you could not see that it was unbuckled, as he was barely tall enough for the ride mabye 56" and he was on the inside of the train.

That doesn't mean anything. I operated a stand-up coaster with the same restraint system, and you can, contrary to what you think, notice if someone unbuckled their seatbelt. No matter where on the train they are. Ride ops absolutely love to stop rides, so trust me that they are attentive when the train is in a location where it can be stopped. Especially if the person was goofing around in the station. We always kept an eye on people we thought would misbehave.

[flgirl]

The more I read and hear about all the problems the 6 flags parks have the less I want to visit them.

Originally posted by flgirl
The more I read and hear about all the problems the 6 flags parks have the less I want to visit them.

Well flgirl, I am a pass holder with six flags and i personally cannot speak for all of six flags parks but I can speak about SFOG,
My family and I have been to sfog probaly about a dozen times, and I have not seen any neglect or carelessness when we are loading or waiting in the que to load. Believe it or not. The welfare and safety of my family is allways at the front of my mind.