There are still horrific crashes...
There are still horrific crashes happening in stock-car racing. The good news is we have a survival rate much higher now than at any time in history. That being said, we can't rest on our successes. We all need to be diligent where safety is concerned and work to design the safest environment possible in which to race. JOE ALEXANDER
Race car safety includes a number of areas of concern. We have the actual chassis design, the various add-ons to that chassis that are available, the seat and restraint equipment, our fire systems, the driver's apparel, and the design of the racetrack that influences our safety. Those, along with the team's level of safety awareness all add up to what should be a high level of survivability.
At some point in our preparation for the new season, we need to address, review, analyze, plan, and enact safety measures that will help prevent serious injury or death in the event of a crash. Staying safe from harm is of utmost importance and we need to be thinking about all of the factors that go into that well before anything happens. Here are the major areas of interest concerning race car safety.
Basic Chassis Design One of the most critical areas of concern for chassis design is stiffness. Over the years, racers have been seriously injured and killed by the force of impact with the wall or other objects. The injury that results in the leading cause of death in these types of crashes is basil skull fracture. It's the very same injury suffered by someone who is hung by a rope.
In short, death is caused by the body stopping in a very short distance for a very short duration of time, and the head continuing forward at a high rate of speed. The neck is not designed to hold back this extreme force and the tendons that hold the skull and vertebrae together break with extreme damage to the brainstem, spinal cord, and blood vessels.
It's the framerail that needs...
It's the framerail that needs to bend in order to absorb the energy created by contact with the wall. If these rails are straight and/or too stiff, then the g-forces--up to 70 g's in some cases--have no where to go but into the driver. A head that weighs 15 pounds becomes 1,050 pounds instantaneously in a 70 g hit. BOB BOLLES
The impact with a wall or light pole or other fixed object while traveling at a high speed generates a lot of energy. The more time it takes for the speed to be reduced to zero, the less g-forces that are transmitted to the driver's body. Something must give and move in order to extend this time sequence. Either the wall (or whatever is struck) must move or give way, or the car must crush. It's the crush factor, be it the object struck or the vehicle, that helps us survive.
In past years we've seen some horrific crashes that were survived or not due to the level of crush factor. In the truly stock race cars of the 1960s and 1970s, speeds were reached that equal or exceed today's stock car speeds. Drivers hit the wall at very high speeds with much less adequate protection than we had in the 1990s, but survived. Why?
Cars of yesteryear were built on the original chassis. These frames were stamped into a shape that was convenient for attaching the body and suspension parts and there were lots of curves and hardly any straight pieces. Curves in steel parts easily bend. So, as these cars struck the concrete walls, the chassis bent and absorbed much of the energy of the crash. Injuries and deaths started occurring when we started fabricating special chassis for racing that had more straight lines and less curves.
This is an example of a stiffly...
This is an example of a stiffly designed chassis. There's very little angle formed when the main rail extends forward from the firewall. This causes the front chassis to be very stiff and not absorb much energy in a crash. Cars built similar to this were a cause of injuries and fatalities in the late 1980s in the Northeast Modified series. BOB BOLLES
Today there are a majority of race tracks that have naked concrete walls without energy absorbing coverings. All of the crush factors must be designed into the race car chassis if we expect to dissipate the energy of a crash. Race car builders must be aware of this need as they design a new chassis. If not, the driver of that car is at risk.
Intrusion Protection One of the more rare injuries we see with race cars is when outside objects protrude into the car and injure the driver. The object can be a driveshaft separated from another car, a lost bumper, the end of a guardrail, a tire and wheel that has come off another car, and more. We need to provide protection from intrusion with our chassis design.
Plating the side bars help prevent side intrusion and this plating should extend forward to protect the front of the foot box. Netting beside the driver's head helps keep the head and arms inside the car, but can also keep objects out of the cockpit too.