Stunt Industry
The air bags currently being used in the Stunt Industry are out of the dinosaur age. We have a far better bag.
The stunt industry has developed the current technology to be as efficient as it can get but this technology has inherent flaws that are insurmountable:
1. THE VELCRO RELEASE PROBLEM:
The current crop of stunt bags are effectively a 'bouncy castle' design and — to overcome the fact that this will simply bounce the impacting body off the bag after impact — these bags have a Velcro release at the side of the bag. The principle is that – as a body hits the bag – the Velcro tabs release and allow the air bag to effectively deflate. This system can be seen on this video clip: The problem is that to 'explode' the Velcro tabs a given pressure is required but to achieve that pressure point and activate the Velcro tabs requires the body to hit the 'sweet spot' in the centre of the bag. If the falling body does not hit the sweet spot, the bag remains a bouncy castle and the person bounces off the bag to peril. This is illustrated here: http://www.precisionstunts.com/airbags/airbag.html
The problem is that to 'explode' the Velcro tabs a given pressure is required but to achieve that pressure point and activate the Velcro tabs requires the body to hit the 'sweet spot' in the centre of the bag. If the falling body does not hit the sweet spot, the bag remains a bouncy castle and the person bounces off the bag to peril. This is illustrated here:
A 28-year-old female stunt woman (the victim) died after jumping 44 feet from a building during the filming of a movie. The victim was performing a jump called a backward fall. The victim had been a stunt person for about five years. She was considered to be an experienced stunt woman although she had not performed a backward fall rehearsal jump at this site. This maneuver required that the victim fall backwards off the side of the building and land on an air bag. She pushed off from the side of the building, landed on a corner of the air bag, bounced off it, and struck her head on the asphalt surrounding the air bag. The air bag that was used was designed for heights no greater than 40 feet. It also required three to five feet of space surrounding it to allow for adequate venting and deflation. Because of space limitations, one side of the air bag was positioned against the building from which the victim jumped, leaving three and one-half feet of space on the opposite side of the bag. The two short ends of the bag were not restricted. There was no venting space along the length of the bag that ran parallel to the building. In addition, the building and asphalt adjacent to the air bag were not padded. The employer assigned four persons to act as ground spotters. A fifth spotter was located on the roof with the victim. The CA/FACE investigator concluded that in order to prevent similar future occurrences, employers should: To see the full case go to: http://www.cdc.gov/niosh/face/stateface/ca/94ca018.html
The Krush Kushion system is far superior because it works in a completely different way and allows for falls right up to the very edge of the bag without bouncing the person off.
To see the full case go to: http://www.cdc.gov/niosh/face/stateface/ca/94ca018.html
2. THE CATASTROPHIC FAILURE PROBLEM:
Most current stunt bags consist of just one single sheet of PVC. It the bag splits under pressure – the body hits the floor.
A.J. Bakunas, in the movie Steel
Bakunas doubled for George Kennedy in this film about a construction foreman battling his fear of heights following an accident. The stuntman was suppose to land on an air bag for Kennedy's character's fall from a high-rise, but the bag split open and Bakunas struck the ground and was killed instantly
The KK system is far superior because it works in a completely different way and allows for falls on the very edge of the bag without bouncing the person off.
Some modern stunt bags of the classical design no have at least two chambers which prevents this catastrophic failure.
3. THE INDENT RESPONSE PROBLEM:
The other shortcoming of the ‘normal’ stunt bag is that – because you are essentially landing on a ‘flat’ surface – you have to land on your back or risk serious injury.
To explain:
The ‘Indent Response’ Principle: You have to land on your back because the surface is ‘flat’ and taut and does not readily indent in a localised area. This is because the surface of the bag is under tension because it is holding in the air in the bag. In order for that flat surface to be indented in a small localised area, a large area of the top surface has to indent and an enormous amount of air has to be shifted from underneath the impacting body. This takes time and creates an ‘indent response lag’ and this by definition constitutes a relatively hard surface.
By contrast – the Krush Kushion surface is not under tension at all. The top surface sheet merely ‘floats’ on top of the cylindrical tube ‘fingers’ and to indent the surface sheet only requires the relatively small amount of air in the tubes immediately under the falling body to be squeezed out into the base bag below. This principle is exactly like the shock absorber in a car and the indentation is immediate. This means that protruding limbs (such as a head!) are indented into the surface of the bag far more efficiently and we have created for the first time ever an air bag where you do not have to land on your back to be safe.
