Side Impact Protection

Press, Volume CVIII, Issue 31783, 13 September 1968, Page 19

Side Impact Protection

AN important step towards the production of safer cars has been taken by General Motors, the industry’s biggest manufacturer. After two years research, it is to incorporate built-in crash bars into the doors of most of its 1969 model American made cars, to protect passengers against side impacts, writes John Langley in the “Daily Telegraph.” Penetration of the passenger compartment in a side collision is one of the most lethal types of accident. It is also one of the most difficult to guard against, because there is so little energyabsorbing space between the outside sheet metal of the doors and the unprotected passengers inside.

INTEREST Engineers in the British car factories are awaiting further news of the General Motors developments with keen interest. They, and other manufacturers, have been asked to let the United States Federal safety authorities have their suggestions, by July, for reducing the effect of side impacts.

Investigations by the Road Research Laboratory indicate that in crashes on British roads, 12 per cent of cars are rammed in the sides, compared with 60 per cent invol-

ving frontal impacts and 7 per cent hit from behind.

DIFFICULT When I visited the Mer-cedes-Benz • research centre two years ago, one of their leading safety engineers confided that the question of absorbing side impacts was one of the most difficult problems they had to face. Fore and aft impacts were much simpler to cope with, by designing shock-absorbing front and rear ends. Mercedes at that time was considering building a honeycomb of steel mesh inside the doors for extra strength. General Motors, one of the main targets of the American car safety crusader, Ralph Nader, believes it will be the first manufacturer to go into production with an effective form of side protection. Its solution is to build a “chain” of steel running the length of each side of the car. Light, but strong, box-sec-tion steel girders will be built into each door, stretching horizontally about 10 inches above the step. The idea is to disperse the impact of the oncoming vehicle: in a violent collision, the car which is struck will be pushed out of the way, instead of having its occupants crushed by 1J tons of car penetrating the passenger compartment.

Door pillars, latches and hinges are also being reinforced to strengthen the side structure. These changes are expected to add about 491 b extra weight to a four-door saloon.

One of the problems is finding room for the lowered window glass in the reinforced door. General Motors has solved this by locating the crash bars between the lowered glass and the steel skin of the door. Nearly 70 cars were destroyed in broadside test crashes during the development of the new system by the Fisher Body division of General Motors. U.K. RESEARCH

In Britain, manufacturers are working on the problem through the Motor Industry Research Association. The public demand for wide seats and full-width interiors has increased the hazard and in most modern cars the occupants sit perilously close to the danger area from a side impact. Some manufacturers, such as Rover with the 2000 and NSU with the RoBo, have set their seats well inside the car to reduce this danger. But it seems probable that all makers will eventually have to introduce further safeguards along the lines now pioneered by General Motors.