human cannonballs

This is an obscure subject that I’ve spent exactly zero minutes of my life contemplating. I had forgotten that human cannonballs even exist.

They do exist, however there’s only a few of them active these days. Circuses are typically filled with phoney scary illusions to add to the drama and theatrics. But the human cannonball act is actually even more dangerous than it looks. Circus historian Antony Hippisley Coxe has estimated that of the 50 human cannonballs known to have attempted the act, more than 30 died on the job.

Lots of trade secrets for this act, for competitive reasons everything’s classified. But this much we do know: they don’t use gunpowder as the propellant. It’s pressurized air. The 24 foot barrel of the cannon is typically raised to an angle of 39 or 40 degrees, depending on the size of the arena. The cannon is heated to a temperature between 65- and 75-degrees Fahrenheit (presumably, this is to ensure that the pressurized gas used to power the cannon behaves as expected come showtime). Total flight time: 2.6 seconds for a distance of 100 feet at a peak height of 75 feet. The world record for distance is 193 feet. (That video is incredible.)

Upon exiting the cannon, the acrobat is traveling between 60 and 66mph. In other words, there’s some g-forces involved. Maybe 6 or 7 g’s, depending upon what you plug into the equation. The average person can withstand maybe 5 gs before passing out.

Everything you've ever wanted to know about human cannonballs but were afraid to ask can be found here.

Ringling Bros' current cannonball is 25 year old Gemma "The Jet" Kirby:

I recall seeing a show where a "celebrity" was trained to do this act. I wondered how hard could it be? It seems the machine does all the work. Just lock your knees, keep your chin down, and try not to over rotate the landing.

Then you realize how many folks die doing this act. I vaguely recall one report of an incident where the catch net wasn't put up at all.

I wonder what a cutaway looks like. I imagine it as a piston pushing a sled, since the flyer comes out in a Superman pose, rather than tucked in a ball. However, what if the mechanism was actually a bundle of bungee cords, and it was actually a big slingshot? Maybe that's why it is such a secret?

Quote: Ayecarumba

I wonder what a cutaway looks like. I imagine it as a piston pushing a sled, since the flyer comes out in a Superman pose, rather than tucked in a ball. However, what if the mechanism was actually a bundle of bungee cords, and it was actually a big slingshot? Maybe that's why it is such a secret?

That's good thinking. I always envisioned the piston just pushing on your feet, and always wondered "what if a knee buckled?" The sled would prevent that.

But what if you slipped off or couldn't hold onto the sled? You'd buckle and come out all cattywampus. Now I'm thinking it's like an aircraft carrier. Hook on and go for a ride. Even if you were dead before launch, you'd still go flying as intended.

Good question, this.

When David Letterman interviewed Kirby, she said she accelerates from 0 to 60 mph in 0.25 seconds. Try that in a Lamborghini/Ferrari/Porsche...

Quote: reno

When David Letterman interviewed Kirby, she said she accelerates from 0 to 60 mph in 0.25 seconds..

Normally when you jump out of a plane that is 0 to 60 in 3.5 seconds. If you dive headfirst out of a plane you must be able to speed that up a lot, but nowhere near 0.25 seconds.

How long have human cannonball acts been around? Was there ever a time when they actually used gunpowder as the accelerant?

I am still puzzled by the mechanism. How do you apply that much force to the human body without causing damage.. and still allowing the flyer to come out of the end of the barrel in a Superman pose? I would think the g-forces at blast off would prevent someone from holding their arms out, but that is the position in the time lapse picture above.

Quote: Ayecarumba

I would think the g-forces at blast off would prevent someone from holding their arms out, but that is the position in the time lapse picture above.

Clearly, they can't be clamped down. If the clamp didn't release then you would tear your arms off. I am guessing there is some kind of spring mechanism which depresses so your arms are held in place. But given 3000-5000 lbs of force, it had better be a fast acting mechanism that depresses it so that you body is not severely bruised.

The one thing that is clear is that the "sled" is actually an internal cylinder. If it was less than 360 degrees, then you might roll off and misfire. As far as I can tell, all the fatal accidents were all on landing. The first human cannonball was a 14 year old girl, who eventually broke her back.

There was never gunpowder used as the accelerant. The original acts in the 19th century used springs, which were replaced roughly 50 years later with air cannons that permitted longer distances and heights.

The video posted earlier of 193' horizontal is the record distance. His father still holds the record height of 201'.