The maker of a new seat-belt system, which may reduce fatalities in car collisions by as much as 50 per cent, is seeking car manufacturing partners to test the system.
Swedish automotive safety firm Autoliv expects to hold the first in-car tests of the Combo-Belt - first reported in Motors on June 4th last - by the beginning of next year, Matts Odemann, corporate communications manager, told me last week. The system could be ready for mass production by January 2005.
Test data from laboratory trials indicate that the system, which consists of standard three-point belt and supplementary two-point belt, will be 30 per cent more efficient in frontal crashes than the traditional three-point belt.
Odemann estimates that, when combined with the newly designed Side-Support Airbag (SSA), the number of fatalities and severe injuries in "far-side" impacts and "roll-overs" could be cut by as much as 50 per cent.
Currently, the risk of death or serious injury in a collision is about 50 per cent when a vehicle is struck on the far side by another passenger car travelling at 65 km/h (40 mph).
In the tests of the new system, however, conditions were set to simulate a 100 per cent risk of life-threatening head injuries. They show that the risk of such injuries was eliminated completely - the test dummies remained firmly in the seat with adequate distance to the vehicle's side despite a significant side intrusion.
"As yet the new system hasn't been tested in driving conditions," said Odemann, "but results show that the number of fatalities on European roads - about 10,000 annually at the moment - could be reduced by up to 5,000 once the system becomes an industry standard."
Although none of the elements in the Combo-Belt are new, he says, the concept of combining three or four different safety aspects in the one system is. "We had originally played with the idea of using the four-point seat belt currently used in racing cars. But European regulations don't allow for it. So we came up with the idea of the Combo-Belt."
The new system creates a cocoon around the driver, the front-seat passenger - and, if applied in the back seat as Autoliv anticipates, the back-seat passengers. In the event of a collision, the cocoon will prevent passengers knocking against each other, one of the major contributing factors to fatalities.
Although traditional three-point belts reduce the overall risk for life-threatening injuries by as much as 60-70 per cent, they are less efficient in roll-overs and in side-impact collisions to the far side (when the occupant is sitting on the opposite side on which the vehicle is struck). In such crashes, the occupant's torso often slips out of a three-point belt, and the head violently hits the inside of the car.
To address this problems, Autoliv added a two-point seat belt as a supplement to the existing three-point belt. The new seat-belt is attached to the top of the seat and crosses the regular three-point belt. It can be buckled only after the regular belt is buckled.
As an additional improvement, a new airbag at the inside edge of the seat back will also be installed. This Side-Support Airbag (SSA) inflates to three litres at the height of the occupant's upper arm in far-side impacts and in rollovers.
The new airbag keeps the occupant in the seat even if the he or she is using only the three-point belt. If both belt systems are used, it reduces the load onto the occupant's neck in violent far-side crashes and roll-overs.Side-impacts cause about 50 per cent of all life-threatening head injuries to drivers in car-to-car collisions, according to American accident data.
The new system was also tested in the most frequent type of roll-over. They represent 60 per cent of all roll-over accidents in the US, where they cause 130,000 serious head injuries every year to belted occupants alone, disregarding the unbelted occupants who will not be helped by better seat-belts.
In these tests, the force by which the head hits the inside of the roof was reduced by more than 50 per cent, when the pre-crash head-to-roof distance was 100 mm (about 4 inches), and the risk was eliminated completely when the distance was 120 mm (about 5 inches). The typical head-to-roof distance is 100-120 mm for a mid-size male.