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Big Grizzly Mountain Runaway Mine Cars

Discussion in 'How do they do that?' started by MattyMitch, Jul 30, 2016.

  1. MattyMitch

    MattyMitch Member

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    I was wondering how they do the backwards part.

    From my understanding lift hills work like this;
    The chain dog (I think it is called that) latches on to the chain.
    The chain moves up and the anti-rollback device clicks in between the grooves on the track.
    Then once the chain reaches the top the car move off the chain.

    But on the lift hill on the big grizzly mountain runaway mine cars it somehow manages to go backwards. But I can see the anti rollback track thing.

    So at the top does something lift the anti-rollback mechanism up?
    Thats my guess but I may be wrong.
     
  2. lazyboy97o

    lazyboy97o Well-Known Member

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    Anti-rollback devices no longer have to be static, fixed in place features. When the switch is thrown and properly engaged the anti-rollback is disengaged. Expedition Everest does not make the loud clack-clack-clack because it's anti-rollback equipment also lowers to avoid the noise.
     
  3. Rob562

    Rob562 Well-Known Member

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    Well, kinda... I think you mostly know the system, but maybe aren't describing it clearly...

    The Everest anti-rollbacks work because they essentially have a flywheel attached to the anti-rollback "dog" under the cars. As long as the car is moving forward at a constant speed, the flywheel keeps the dog lifted up and away from the teeth in the track. But should the train stop moving forward (such as in a rollback situation), the dogs would drop and engage the teeth. That's why you can hear the clatter of the dogs as the train enters and leaves the lifts, the train isn't going at the proper forward, constant speed.

    I'd have to look at video of Grizzly Mountain again to see what the track looks like to hazard a guess on what they're using.

    Edit: OK, I've watched this video with a front-seat POV:
    (jump to 7:15 for the appropriate section)


    On the reversing lifthill the train is being pulled up by a chain, but the chain doesn't act directly on the train. The chain actually has a catch-car on it that engages a fin under the train and pulls it up. (You can see it in the video as the train starts to roll backwards) At the proper moment, a device in the track essentially squeezes the catch-car and releases its hold on the train.

    Now the anti-rollback dogs are another story. I can see where there's the "teeth" in the track on the hill, but there's also a fin running to the right of the teeth. At least some of these sections of fins appear to be leaning to the right as the train is heading backwards. But I'm having trouble envisioning how that would be advantageous in how the fail-safe anti-rollback systems I'm used to operate.

    -Rob
     
    Last edited: Jul 31, 2016
  4. MattyMitch

    MattyMitch Member Original Poster

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    Ah yes, I can see the catch car at the top. Maybe the fin pushes the anti-rollback off of the teeth.
     

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