Most people associate parachutes with skydiving, para sailing, or military operations, but they have been critical over the course of auto racing as well. For those who follow drag racing or land speed records, parachutes being deployed at the end of the run is a common, and reassuring sight. Dragsters and funny cars can go from zero to 320 MPH in 3.87 seconds. There is no way these cars could stop as effectively without perfect parachute design. Most people also don’t realize that there are two very distinct designs used in drag racing, the Simpson design, and the Stroud design.
The Stroud design came from necessity. The cross-form has been proven effective in the faster cars, namely top fuel, and funny car in the professional classes, as well as top alcohol and top alcohol funny cars in the amateur classes. These are great at stopping cars over 200 MPH. However, there are a number of categories in drag racing where the cars run under 200 MPH and the cross-form deploys too roughly, and would drag the car up. This problem was confirmed by Bill Simpson himself. When he first tested the cross-form at 100 MPH the car took off, and he was hospitalized and arrested. Bob Stroud, who is an engineer who has made a number of designs to airborne parachutes worked on the problem, and came up with the current design in the 1980’s. While Stroud developed the chute, many companies have made design changes.
For a time, these designs were relegated to the amateur classes of the NHRA. It was in May of 1990, at the AC-Delco Southern Nationals at Atlanta Dragway that the Stroud design came to the professional leagues, stopping Warren Johnson at the end of his races. It should also be noted that at that time, many drivers simply didn’t deploy their chutes at the end of a run. While their design has evolved over time, it still remains the standard for cars that race up to 205 MPH. This example comes from Pro Stock legend Warren Johnson’s post 2009 career. It shows a decent amount of wear. The chute canopy has an opening in the very center, for air to go through. The pilot chute is attached here as well. Pilot chutes are universally used to deploy parachutes. When the cords are pulled, and the chute is released, the pilot chute deploys, which catches air and pulls the primary chute behind it. The parachute has a tag from the Stroud Company stating is was made in 01/09.The chutes are strapped to a bar at the back of the car, the straps pre-covered in Nomex to prevent fire damage, then packed into a bag, before the race. These parachutes and pilot chutes are massive, but are packed into a bag which measures 9 inches square. There are two designs that are used to launch a parachute. There is the empty box design, which mounts to the back of the car, and is opened by pulling the cable. The second is a pneumatic launcher, used with smaller cross form, and most Stroud chutes. Drag racing parachutes are almost always packed by the drivers themselves. As one driver so elegantly phrased it, “If doesn’t work, I have nobody to blame but myself.” How do drivers pack their own chutes? I’ll let driver Rickie Jones explain that:
Next week, the Pedregon Family is profiled again.