It was discovered that the...
It was discovered that the window net on the left side did not adequately control head movement to prevent impacts with the wall in left-side collisions, so left-side head nets were installed in stock cars. The Sprint Cars use left- and right-side head nets.
One of the main areas of concern is the mounting of the tachometer. This is an accessory that is often attached using hose clamps. Anything added beyond the normal parts of the interior and rollcage should be bolted to a rollbar with bolts that sustain it in case of a wreck. Other cockpit accessories that are commonly mounted incorrectly include the coil, the on-board computer, the radio, the drink bottle, and the fire extinguisher. Once the basics of cockpit safety are reviewed, it is time to look at more advanced levels of safety.
The most basic racing seatbelt system is the five-point system with two shoulder belts, two lap belts, and a submarine belt. To gain additional body control, the five-point system can be changed by replacing the single sub belt with two individual belts to control the motions of each leg. This system is called the six-point harness.
The six-point harness system is a vast improvement in body control compared to the five-point, but there is still another way to increase a driver's body control. In the typical six-point system, the leg belts snake through a loop in the lap belt and hook into the shoulder belts. This belt arrangement puts an odd angle on the direction of force for the tightening of the shoulder belts.
Advanced cockpit designs offer...
Advanced cockpit designs offer very strong support brackets to reduce flex in the head surround support as well as the shoulder support. Photo by Bob Bolles
One way to keep the benefits of the leg control of the six points and keep the belts in an optimum alignment is to add the single sub belt so that the shoulder belts pull against it. This belt system is offered by many manufacturers.
Seat foam molds are used to fill the void between the driver and all parts of the seat. This spreads the impact loads over a larger area of the driver's body to reduce the unit loading. There are two types of foam molds.
The most popular mold has foam that expands inside a plastic bag while the driver is in the seat. The foam expands into the void areas, surrounds the driver, and then hardens. It is normally covered with a protective fabric.
The second type of foam mold is the polystyrene bead mold, which is created by fitting a bag of polystyrene beads into the seat, and having the driver sit in it. All the excess air is sucked from the bag, and a resin is inserted to bind the beads together. When the resin hardens, the driver is removed and the polystyrene beads are fixed in place. This type is most popular in Indy racing. Both methods allow the impact loads to be spread over a larger area of the driver's body.
This Super Late Model cockpit...
This Super Late Model cockpit has all of the adjusters, the MSD box, and the fire bottle securely bolted to the rollcage bars. If a modern seat was installed, the driver would be much safer. This driver was in a serious crash and sustained life-threatening neck injuries. A proper seat and a head-and-neck restraint might have helped.
On the subject of seat foam molds, it is important to understand that foam molds are not substitutes for high-quality seats or correct seat design. Some have suggested that the combination of non-rib seats and foam molds may provide adequate protection for the ribs, lower back, and spine support. However, on-track result do not support this suggestion. There is no substitute for a quality seat, and a seat foam mold is only an addition to a safety system and not a band-aid for lesser designed safety products.
The following statement is from noted racing physician Dr. Terry Trammell: "Safety is not a driver's right; it is a driver's responsibility." It is important to understand that just like your race engine, your safety equipment is a system in itself. Any addition to your safety program must not only consist of high-quality products, but also must fit well into your overall safety system.
By Bob Bolles
We spoke with Randy LaJoie, who manufactures racing seats and systems for stock cars. He agrees with the information presented in this article and adds that it is very important for the seat components to be rigid in order to properly protect the driver in all crash situations. We thought, like many others, that some flexing of the seat and head supports might absorb some of the energy in a crash. But we didn't consider the other consequences, such as secondary impacts and their effects on the driver if the seat components are bent out of place. According to LaJoie, "No driver has ever been hurt by the seat not moving."
If a seat bends upon impact, then it no longer fits the driver snugly. From that moment on, the driver is sitting in a seat that does not securely fit his or her torso, and that translates into a lot of movement and possible injury in a secondary impact.
If the head support bends away in an impact, then the head has farther to go to reach the support in a second or third impact. Contact with the rollcage or track wall is now possible, not to mention possible neck fractures, whereas a rigid support will keep on locating the head where it should be in relation to the body. To prevent serious injury, all of the body (head, chest, and hips) must stay in line upon impact. Modern race seats make that happen. We thought it necessary to clarify this point.