A well-designed racing cockpit...
A well-designed racing cockpit is a system that takes into account all aspects of driver safety. Knowledge has increased related to protecting drivers from harm.
No racer thinks a wreck is in his or her future, but it happens far too often. So many drivers get odd injuries that could have been prevented. Taking a thoughtful and careful look around the cockpit allows any racer to improve his or her safety. Follow along and learn about how a better understanding of your environment can help you survive a crash.
The seat should be mounted to the rollcage or a structural member of the frame. It is always better to use manufacturer-supplied mounting rails, because they are specially built for your seat. They properly mount the bottom front and bottom rear of the seat. Seat rails should be bolted to the seat with Grade 8 3/8-inch bolts, heavy-duty large flat washers, and lock nuts. The bolts must be spaced as far apart as possible to properly distribute the load.
The seat should be tied into the horizontal tubing that runs behind the seat. Instead of bolting through the tubing, it is better for strength purposes to weld on a bracket and then bolt through that. The bolts should be vertical so that they are in shear.
A bracket that supports the entire width of the seat is best. Spreading the load provides a more secure mounting. A minimum of four Grade 8 5/16-inch bolts, heavy-duty flat washers, and lock nuts spaced as wide as the width of the seat should be used. Again, a manufacturer-supplied bracket should be used whenever possible to connect the seat, the rear bar, and the mounting flange.
The seat system must protect...
The seat system must protect and support the areas shown in the boxes in order to ensure a safer impact that spreads the g loads in a crash.
In an accident, one of the first areas of the car that your body hits is the door bar. This large area is very close to the seat and well within reach of your swinging arms. Roll bar padding on these bars help, but you can still slide between the bars. Most teams use full-sheet door pads. This is a piece of fire-retardant material that has an impact-dissipating foam laminated to the back of it.
A driver's safety in the cockpit has a lot to do with the quality, mounting, and care of the seatbelts. We have discussed these topics in previous articles, but they can never be mentioned enough. There are a few concepts to think about when buying, installing, and using seatbelts.
1. Better belt materials: In the early days of racing, seatbelts were made from the same thing that military belts were made from, which was cotton webbing. As technology advanced, it was found that nylon was a better choice for longer life and higher strength. In the last 5-10 years, polyester and combinations of materials have made their way into the market of competition seatbelts.
The seat must be mounted firmly...
The seat must be mounted firmly to the rollcage structure. Here is a mock-up of a Sprint Car seat and the actual installation in a Sprint Car. The strong supports for the head and shoulders prevent lateral movement. Photo by Bob Bolles
These materials have been preferred because of the small amount of stretch compared to the average nylon stretch numbers, but this should not rule out all nylon belts. There are quality nylon belts on the market, and the price difference between nylon and polyester does not always gain the stretch advantage for the price a racer is paying.
2. Keeping the belts as short as possible: As we just mentioned, all belt webbing stretches. The amount the belt stretches is a function of the tension load placed on it and the length of the belt this tension is applied to. The more the belt stretches, the farther the driver moves in the seat and the greater the likelihood of injury. Shorter belts lessen the stretch.
3. No sternum straps: When they were first developed, sternum straps were used to keep the shoulder belts closer to the middle of the chest and keep them from sliding off the shoulders. What has been found since then is that these straps are neck injuries waiting to happen.
As the driver's torso moves forward in a frontal impact, the shoulders slide on the belts and the sternum strap moves toward the neck. There is no fix for this. Proper mounting and the use of short belt lengths will accomplish the goal of keeping the belts on the driver's chest.
This car has two head nets...
This car has two head nets that further prevent movement of the head during violent crashes and rolls. Photo by Bob Bolles
4. Proper mounting angles and hardware: The SFI Foundation has an article on its Web site (www.sfifoundation.com) detailing proper belt mounting methods, angles, and procedures. There are other articles and diagrams on the Web, but SFI's site has such a wealth of safety knowledge that it is worth the look.
5. Certifications and age: Any quality belt system has a certification tag. This is the manufacturer stating that the belt meets the minimum standards set forth by a certifying foundation under a certain specification. Most belts in America, and quality belts from overseas, have an SFI tag. The belt should also have a tag that states its date of manufacture. It is commonly held that a set of belts should not be used more than two years after its date of manufacture.
The legs make up the largest mass of the body that is unrestrained. During an accident, the driver's legs are free to hit anything from the transmission tunnel and shifter handle on the right side of the cockpit to the door bars on the left. To control the driver's leg motions, it is important to utilize leg braces and a steering column mounted knee knocker.
The leg braces are run from the front of the seat on the sides of the legs to the front firewall, or as far forward as reasonable. The braces should be made from a substantial aluminum. The edges of the braces should be bent over, not only for strength, but also to eliminate another opportunity for the driver to be cut.