jerk vests, flying refrigerators, etc.Re: [Beowulf] Re: "hobbyists"

Jim Lux James.P.Lux at
Tue Jun 24 10:19:20 PDT 2008

At 09:25 AM 6/24/2008, Jim Lux wrote:
>At 02:31 PM 6/20/2008, Peter St. John wrote:
>>The destructive radius of Little Boy was about total, up to about 
>>one mile radius, and tapered down to light at about two miles. So 
>>being in a lead-lined steel container at 2000 meters might be OK for Indiana.
>>In all action movies, blasts throw people unhurt for long 
>>distances; when that much force (to impart that much momentum) 
>>would kill you. That part is just conventional Hollywood. I could 
>>teach RGB to kick me so that I fly through the air as in a Bruce 
>>Lee movie; it's a stunt, and real kicks reallly hitting drop you 
>>like a sack of potatoes, I've seen it. But not in movies. Similarly 
>>bullets, they drill holes in you, if they pushed you through the 
>>air the recoil would do the same to the shooter.
>>As for the scene's good taste I can't say, I haven't seen the movie yet :-)
>As someone who used to work in the business of doing this sort of 
>thing (e.g. physical effects) for movies, TV shows, and commercials, 
>you can assume that whatever you see on screen is specifically 
>designed to "look like" what the director thinks will create the 
>correct impression in the viewer. (e.g. real rain is invisible on 
>film, for all intents and purposes..)
>For blasts (or kicks, etc.) flinging folks about, they use what is 
>known as a "jerk vest" (for the high third derivative of position, 
>not to describe the wearer) and bungee cords, springs, hydraulic 
>winches, etc.  Note well that the effects tech just runs the 
>gear.  A stunt person (aka human sandbag) survives the loads (and 
>gives thanks to Stapp).
>To fling things about, we used a variety of things.. air power is 
>popular, so is gunpowder. (look under a car that flips over for the 
>piece of telephone pole used as the piston in a one-shot internal 
>combustion engine.)  Speaking of refrigerators, air pressure is just 
>fine for a hundred meter or so launch.

For some examples:
jerk vest test

refrigerator launch gives a lot of examples

has variety of specific effect tests.  Search for 'air mortar' for launches

Naturally, I'm particularly proud of the tornado and multicam, since 
I helped make them... tornados from Swordfish (stuff done 
more recently, now with digital cameras, which makes life MUCH 
easier..)  Eadweard Muybridge would be proud of us.

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