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Yeah Right!

Discussion in 'Safety' started by elite1trek, Nov 2, 2008.

  1. elite1trek

    elite1trek Active Member

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    So my director just called me. She asked if we could drop real bricks from the grid onto the stage (like, with actors on it), so that we could have realistic sounds. :shock:

    I told her no, of course. I also explained how the brick on wood would not sound real anyway. She seemed to understand the second point more than the safety thing. :rolleyes:

    I just thought I would post this so we could all have a good laugh. :lol:
    It does make me worry though, about less safety-concerned venues, that think dropping bricks is acceptable. :(

    What other crazy stuff have you been asked to do?
     
  2. TheDonkey

    TheDonkey Active Member

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    What were the bricks "supposed" to be dropped on to?

    But yeah, terribleness.
     
  3. elite1trek

    elite1trek Active Member

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    The show calls for bricks to be dropped onto concrete. I think the director was looking for what she described as "a chalky shattering sound."
     
  4. avkid

    avkid Not a New User Fight Leukemia

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    But why all the way from the grid?
     
  5. elite1trek

    elite1trek Active Member

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    That's just what she said. The bricks are supposed to come from heaven.
     
  6. avkid

    avkid Not a New User Fight Leukemia

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    Easy solution: make some out of foam, and drop from the grid accompanied by the proper SFX.

    The sfx should be quite easy to capture with basic equipment.
     
  7. TheDonkey

    TheDonkey Active Member

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    Correction: Made of foam with the center bored out and filled with something slightly heavy

    Pure foam would float down because of air drag >.<
     
  8. elite1trek

    elite1trek Active Member

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    I am probably going to do that, but attach them to some sort of track line so that they don't hit any lighting fixtures, or bounce around the 2nd electric and hit an actor.

    Maybe I will just build some sort of release system on a lineset, so somebody doesnt have to lay down in the grid for half the show. I know you guys won't approve of DMX for this, but does anybody know of a MIDI interface thing that will do this.
     
  9. DaveySimps

    DaveySimps CBMod CB Mods Premium Member

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    In an old venue I use to work at, the community theatre asked to fly one of their actors on the counterweight system. They were appalled when I repeatedly declined their requests, and went over my head to the executive director of the facility who got mad and gave me a hard time about it, even after I explained the safety implications, and the correct way to go about it (calling Foy or ZFX). Apparently years earlier a previous TD allowed them to do it with their production of Mame. They did so by taking a school yard swing and some rope tired to a batten. I am absolutely amazed someone did not die.

    ~Dave
     
  10. avkid

    avkid Not a New User Fight Leukemia

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    I mean like the solid type insulation foam sheets.("blue foam")
    [​IMG]
     
  11. Sony

    Sony Active Member

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    Even rigid foam floats slowly, it's just not heavy enough. It wouldn't look realistic without a little bit of weight added.
     
  12. Van

    Van CBMod CB Mods Premium Member

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    Tripping drop tricks via DMX is perfectly acceptable. Controlling turntables is another matter all together.
    Let's see a brick falling 80' accelerating at 9.8 meters per second per second. And if the average weight of said brick were 5 pounds, that's something like 2.25 kilos...... Yeah that's a recipe for disaster.

    Now as far as dropping foam bricks; I notice we're all saying " Do it like this, then weight them down so they fall better..." Gentlemen, I submit to you that a pound of feathers is not in fact any lighter than a pound of lead, but instead they are the same.
    I would suggest rigging a drop point from a much lower elevation than the grid. Perhaps a drop box on a batten or even a "balloon drop" net between two battens. I would further suggest, for safety's sake, making the bricks out of HD polyurethane foam, or just plain old foam rubber. Your bigger issue , other than needing a good SFX cue, will be controlling the bounce when they hit. If it's possible to have them hit behind a ground row or some other scenic element it's going to greatly contribute to the illusion.
     
  13. Sony

    Sony Active Member

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    True...but a standard 2" x 4" x 8" brick is going to be a lot heavier then a 2" x 4" x 8" block of foam and air resistance will slow it down accordingly since obviously we are not in a complete vacuum and it's terminal velocity will be a lot lower. Weighing down the block will help it fall at the proper speed while the foam will provide a margin of safety where if it were to hit somebody in the head it wouldn't do nearly as much damage as a solid block of clay beaning you in the head would.

    I also suggest if you rig it on a line then run the line through a plastic tube in the block, this will help keep it from getting snagged on the cable and you ending up with a levitating brick in the middle of the show :)
     
  14. icewolf08

    icewolf08 CBMod CB Mods

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    Have we all forgotten basic physics? Acceleration due to gravity is a constant. Weight of an object does not affect how fast it will fall. If two object have essentially the same shape and are dropped at the same time from the same height they should hit the ground at almost exactly the same time. If you took a stage weight and a block of wood cut to the same proportions and dropped them, they would hit at the same time. However a heavier object does have more momentum and thus will hit the ground with more force.

    Just because a block of foam is lighter than a real brick does not mean that it will fall slower. Now, the porous nature of foam may affect how it falls, but this can be counteracted by painting the foam with Foamcoat or Sculptorcoat. Fill in the surface gaps to make the blocks of foam smooth and it should fall just fine.
     
  15. fredthe

    fredthe Active Member

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    True, if we lived in a vacuum...

    If it's falling far enough, what matters is terminal velocity. This is the point at which the drag force on an object is equal to the force due to gravity. As basic physics teaches us, the force on an object is the product of it's mass and acceleration. So, mass does make a difference.

    An easy to visualize (and perform) example. Fill one balloon with water. Fill a 2nd balloon with the same amount of air. Drop them. The water baloon will hit first. (And, make more of a mess :))

    Of course, if foam and lead bricks were dropped from fairly low, you porbably wouldn't see much difference. If they were dropped from the grid, the lead one would definatly get there first :grin:
     
    Last edited: Nov 4, 2008
  16. Van

    Van CBMod CB Mods Premium Member

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    Gentlemen, The entire point of my post was/is when dropping things onto actors one needs to keep in mind they are fragile. < the actors not the objects.> Weighing down a piece of EPE foam enough to overcome it's inherent wind resistance < since we don't live in a vacuum> will render it a potentially dangerous object. And when it comes right down to it, Foam rubber or Polyurethane foam has much more impact absorption qualities than most other materials. Coat a piece of EPE foam with VSSSD and I guarantee you'll feel it when it whacks you on the head after an 80 foot fall.
     
  17. mbandgeek

    mbandgeek Active Member

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    Since we are getting into physics, terminal velocity also comes into play... have you ever heard that an ant can fall off of the empire state building hit the ground and be okay, but drop a human off of said structure... i will not finish the rest of that one. You know where i am going with it though.
     
  18. Sony

    Sony Active Member

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    This is true...if we were living in a perfect vacuum. The Foam Block will have a lower terminal velocity and acceleration due to gravity because the air has to do LESS work to slow it down. You may not notice the difference from a short distance...but I will bet you $100 that if you were to drop a normal clay brick and a foam brick at the exact same time from your grid iron at least 40 feet in the air...that the foam brick will hit the ground AFTER the Clay Brick. Surface Gaps have nothing to do with it, if you were to cut grooves in a regular clay brick to make it "less smooth" it would fall at the same rate as it did before.

    The fact is that the mass of the object has to overcome the force of air resistance and while surface area does play a part in this Mass is a larger factor. It takes more force from air resistance to overcome the acceleration of a larger mass. If what you were saying is true, then a box made from Regular Paper, the same size and shape of a brick, would fall at the exact same speed and acceleration as a normal Brick...try it sometime...you will find it to be completely untrue.

    There is nothing Basic about Real Life Physics...what you get taught in High School is Physics in an Ideal world which doesn't actually exist.

    I apologize to the OP for turning this into a Physics debate...
     
    Last edited: Nov 6, 2008
  19. bobgaggle

    bobgaggle Well-Known Member

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    haha, physics. I think the idea was that its not going to hurt as much if its made out of foam, not how fast it will fall.
     
  20. Sony

    Sony Active Member

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    Yea, we got side tracked, anyways...I wasn't saying fill the foam brick so it weighs the same as a clay brick. I mean if you hallowed out a small cavity in the center of the foam and filled it with some sand or something it would add a little weight and make it fall more realistically while not affecting the safety of it too much....it would definitely be better then getting hit with a real brick for sure.
     

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