Rollback

I'm quite surprised that no one else had questions about this yet. I just noticed this on the rollercoaster rollback. You read it and tell me what is logically wrong with this statement.

8/27/1997 - The train on the Scirocco shuttle loop (Schwarzkopf) at Walibi Wavre (Wavre, Belgium) suffers a mechanical failure and gets jammed upside-down in the loop. Passengers were left hanging from their lap bars for about 90 minutes.

Unless I'm totally over-looking the obvious here, I don't get how this can happen. You can hang in an OTSR, but I don't see how you can hang from a lap bar while "upside down." The only thing I can think of is that this is just another case of the media exaggerating the truth. Maybe the train did get stuck on a looping coaster but it probably didn't get stuck at the top of a loop. If someone else understands please explain........

Dante, extremely confused

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"You know its a good ride when you come into the final brake run wiping tears from your eyes."
*** This post was edited by DorneyDante 8/27/2003 3:33:28 PM ***

You can hang from a lap bar. I do it every time I ride a Rock-o-Plane.

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A day is a drop of water in the ocean of eternity. A week is seven drops.

And many will also argue that hanging from a lap bar is safer than hanging from a shoulder harness.

Personally, I wouldn't want to do either. Hanging upside down for a prolonged period (read "longer then 15 seconds") gives me a headache.
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Ripple Rock Amusement Park
Flying Scooter coming soon!

...and the ride did get stuck at the top of the loop. It wasn't a rollback or valley, but a mechanical failure that jammed the train in place, just as Demon was stuck at the top of its loop. That said, I'm not sure the mechanical reason for each getting stuck were the same, but simply that they were each stuck in the same place in a loop and each time with was due to mechanical failure.

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--Maddie--
What do I Listen-To?
May the Schwarz be with you.

I still don't understand how you can "hang" from a lapbar? I would logically think that if you were the person stuck at the apex of the loop, meaning you would be completely upside down, that you would fall from the lapbar and that it wouldn't be enough to hold you in place.

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"You know its a good ride when you come into the final brake run wiping tears from your eyes."

If you have ever ridden any type of ride that turns you upside down and is equipped with a lapbar only, you will see very clearly how you can hang from the bar and not fall out.

Ride a Rock-O-Plane, Skydiver, or a lapbar-only looping coaster and see.

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Ripple Rock Amusement Park
Flying Scooter coming soon!

I have no photos of the incident, which was in EVERY tv news and frontpage of every newspaeper across europe.

The fact that nobody knew what happened and rescue teams were as puzzled as everybody else, numerous camera teams sneaked in the park to film the drama.

The train really got jammed centerloop. Riders in the middle cars were completely upside down for 90 minutes. It was not a nice thing to see. People panicked because they feared to fall down. Relatives and friends at the ground had to witness the horrible situation.

Some people in the train took off their shirts and threw them down out of panic.

After the train got released with a cherry picker, the train (ironically) slid down the loop towards the hill. So the poor passengers were treated to a minutelong ERT until the train finally came to a stop. (That was one of the strangest moments, when everybody was relieved for a few seconds that the horror was over. Then the train would climb dangerously high up the loop and everybody was holding their breath that it would not get stuck again.)

Apart from state of shock , some stretched muscles and cramps (excuse me, I donĀ“t have the english medical expressions, but I guess you know what I mean) everybody left the ride without major injuries.

The lapbars did indeed hold everybody in their seats. People were also able to lean forward, so that they could relieve the bloodpressure in their heads a bit. This would not be possible with OTSR. It must have been awfully painful, though to have your whole weight pressed into the bar.

For once the press did not overblow an incident, it was really dramatic and frightening.

Since then, Six Flags bought the park. Renamed the ride TURBINE and enclosed the loop with an industrial style building. This was not done to muffle screams from possible future incidents and obstruct the view for TV cameras. They built a bridge through the loop to evacuate the ride if this should happen again.

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i was a teenage rollercoaster designer

Yeah but your not "hanging." I have been on many lapbar looping coasters to know that inertia is keeping you from falling out, not the lapbar.

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"You know its a good ride when you come into the final brake run wiping tears from your eyes."

If your lapbar is snug enough I dont see how you can fall out. (Unless you are "bendy" , according to Phoebe in Friends) Plus if that ride has the additional ankle restraints I am sure it's pretty safe.

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Lyrically, I'm supposed to represent
I'm not only a client, I'm the playa president!

...but, Dante, the lap bar is there in case there is insufficient centripetal force to keep you in your seat, such as the train travelling too slowly around the top section of a loop.
Dante,

The lap bar goes from the bootom of the train to right at your stomach at at an angle "\" -> but pointing further down to the left.

Chipster


DorneyDante said:
I still don't understand how you can "hang" from a lapbar? I would logically think that if you were the person stuck at the apex of the loop, meaning you would be completely upside down, that you would fall from the lapbar and that it wouldn't be enough to hold you in place.

Anton Schwarzkopf tested this type of restraint system thoroughly before using it on his coasters. You don't need OTSHs to keep you from falling out of a train. The important thing is that the seats are designed to keep the riders sitting up straight with their feet on the floor and the lapbar does indeed fall in your lap--not your stomach like most PTC bars. Premier uses a similar design on all but one of their LIM coasters (and SOB).

Like millrace said, try it with a Rock-o-Plane it's not at all uncomfortable.

I think there are two Premier LIM coasters with OTSRs -- Mad Cobra and Speed: The Rent Defaulter.


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--Maddie--
What do I Listen-To?
May the Schwarz be with you.

Some more details...

After it happened, someone...I believe a former employee of a Six Flags park with a similar coaster...explained to me exactly what happened, and it makes perfect sense, particularly now that I've seen a Schwarzkopf shuttle loop.

On the back of the train, there is a counterweighted arm which is pulled down with an electrical solenoid. With the arm down, the pusher is engaged with the back of the train, and holds the arm in place. The counterweight tends to cause the arm to swing upward, away from the pusher. The idea is that the pusher shoves the train down the track, then when the train overruns the pusher, the counterweight lifts the arm. That way, when the train comes back through the station, the arm won't hit the pusher. Gravity holds the arm up, out of the way. Even when the train is going through the loop, the forces on the train pull down on the counterweight, holding the arm up and clear of the track.

Through most of the ride, the arm will easily clear the track. But there are two spots, at the entry to and exit from the loop, where the arm can touch the track ties if the arm is down. Apparently, the train launched with insufficient speed. As the train went into the loop, gravity overrode the centrifugal force, so gravity lifted the counterweight, lowering the launch arm. The train didn't have enough energy to make it through the loop, so it started to roll back. The push arm, being pulled down by gravity acting on the upside-down counterweight assembly, drops down, and catches on a track tie, jamming in place. This prevents the train from rolling backward, while the mass in the back of the train hanging down in the loop prevents it from rolling forward. This also explains why, as the train was unloaded, it would roll forward: Take the riders out of the back of the train, its center of mass would move forward, and eventually the mass of the front of the train should bring it down out of the loop.

I understand that when this happened to an unloaded train many years prior to the Walibi incident, the park's solution was to weld a piece of flat bar stock all the way around the inside perimeter of the loop so that the pusher plate could not catch on anything.

As for hanging upside down from a lap bar, try an experiment. Get a chair or stool, and balance yourself face-down on the seat by lying on your chest. Notice that you can't do it. Next, try balancing yourself face-down on that same seat by lying on your pelvis. Notice that it isn't terribly difficult. The difference is that you are supporting your weight at or near your own center of mass. If you do the same in a roller coaster car, you can dangle riders far more comfortably if you support them at their center of mass instead of well above, where it can be downright painful.

--Dave Althoff, Jr.
Who has dangled from lap restraints a time or two, including once in a '95 Taurus...

You can ride Greezed Lightnin' to find out what it's like to "dangle." :)

--Ryan

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A wise Man is one who knows not to play Leap-Frog with a Unicorn.


RideMan said:


As for hanging upside down from a lap bar, try an experiment. Get a chair or stool, and balance yourself face-down on the seat by lying on your chest. Notice that you can't do it. Next, try balancing yourself face-down on that same seat by lying on your pelvis. Notice that it isn't terribly difficult. The difference is that you are supporting your weight at or near your own center of mass. above, where it can be downright painful.


The above statement is 100% applicable if the you are not the one whose part of the train got stuck at the top of the loop. If you were at the apex of the loop, meaning your entire body is upside down, the bar would be pushing on your center of mass but it wouldn't be enough to hold you in your seat since gravity is forcing you downwards . The pressure to keep you from falling out would need to be applied to the top of your body to keep you from falling down. Like I said, your above statement is correct, assuming that you are sitting in the seat anywhere other than the seat stuck at the top of the loop.
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"You know its a good ride when you come into the final brake run wiping tears from your eyes."

Dornney Dante, did you read my post from yesterday(actually a novel;)) I covered the whole incident and RideMan gave a brilliant description of the technical problems.

It really happened like this. People were completely upside down and they were held in place by the lapbars only.

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rocket rocket usa, screaming down the highway

I did read it, I just have a hard time believing it, it's as simple as that. It's one of those things that I'd have to see to believe. Sorry.............I just don't believe it.

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"You know its a good ride when you come into the final brake run wiping tears from your eyes."
*** This post was edited by DorneyDante 8/28/2003 10:54:06 AM ***

Just believe it. Every european coasterfreak saw it on tv.

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i was a teenage rollercoaster designer

I think I remember seeing that on TV here....

Imagine you're sitting in a Schwarzkopf train with the lapbar allthe way down. Now try to stand up...there's not enough room there for you to go anywhere...

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Swat at the sun alongside El Diablo in 2003!
Only at Six Flags AstroWorld!
http://www.houstonthrills.com

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