Contrary to popular belief, cannons used to shoot people into the air do not use gunpowder. Instead, they used compressed air to propel the person forward. When the cannon is fired, a sled in the cannon shoots forward and stops at the top of the cannon with a force of 3,000 to 6,000 pounds per square inch. The person, of course, keeps flying forward, hopefully in a safety net. When setting up the cannon, a few things need to be considered: wind speed, temperature, body weight, distance, and obstacles. If you ask a human cannon, it will tell you that landing is the real danger.
The problem with the landing is that the nets, although they measure about 50 meters; it’s still a small target for a person to land on. Since the landing space is about 50 meters, everyone involved in the trick must constantly measure the wind speed. If they don’t, the person will go off course and end up in a fatal accident. Body weight is also a big contributor. If the person is even a pound apart, he will totally throw the projectile out of the throw. The most important part of the entire launch is checking the person when he comes down from the launch. It is common for the person to have bumps and bruises when he lands. Some bones may also have been broken. The force of the cannon shot can twist legs and fracture and break bones. Before being shot from a cannon, the human cannonball must be taught how to stand in the cannon and handle the pressure of being fired from a cannon. The legs must be in a locked position due to the strength of the initial force that the cannon exerts on the person. If the person’s legs were not in a locked position, the board at the bottom would shoot up and the person’s legs would bend, causing them to be thrown off course and the person would fly to their death.
Another thing the person needs to worry about is g-force. Being fired from a cannon, the person has to quickly accelerate to reach the landing zone. If the person did not train properly to handle the pressure of the G-forces pressing down on his body, he could lose consciousness and miss the landing zone.