Seat Belts Might Have Saved Diana
Washington Post Staff Writer
Wednesday, September 3, 1997;
Seat belts and shoulder harnesses might have saved them.
That is the educated guess of U.S. and European auto safety experts examining available information on the Paris car crash that killed Princess Diana and two others Sunday.
The high-speed slam into a concrete pillar and walls inside a tunnel in central Paris demolished the Mercedes-Benz S280 sedan in which Diana was riding in the back seat with her companion, Dodi Fayed, who died at the scene.
Also killed was the car's driver, Henri Paul, who allegedly was intoxicated. The lone survivor was Diana's bodyguard, Trevor Rees-Jones.
All of the dead reportedly were unbelted. Rees-Jones was belted and was protected by the S280's front-passenger air bag.
Conceding that, for the moment, their comments are based on hunches, several auto safety experts said yesterday that Diana and Fayed might have lived if they had been belted.
"They were sitting in the back seat, farthest from the point of the initial impact," said Brian O'Neill, president of the Insurance Institute for Highway Safety. "Usually the back seat is the safest seat -- if you are wearing seat belts."
French police would not confirm reports that Diana, Fayed and Paul were unbelted. But if the reports are true, that failure probably contributed to their deaths, O'Neill said.
"We know that the impact speed with the post was survivable because the bodyguard survived," British safety expert Richard Cuerden told Reuter. "We expect that people in the rear have as good a chance, if not better, of making it."
It's a simple matter of physics, said William Boehly, an auto safety engineer and former administrator of vehicle safety research and development at the National Highway Traffic Safety Administration.
A body at rest tends to remain at rest. A body in motion tends to remain in motion. Auto crashes are horrific stoppers of motion. And each crash usually involves a three-in-one collision, Boehly said.
There is the initial crash of car into object. There is the secondary crash of occupant into objects within the car, a collision that could be fatal if the occupant is unbelted. And there is the collective third crash of organs banging against one another and against bone structures within the occupant's body.
The inner-body collision, too, is worsened by the severity of the blows to an unbelted occupant striking structures within the car, O'Neill and Boehly said.
"I'm presuming that Princess Di went flying into the back of the front seat so hard it caused massive chest injuries," said O'Neill, whose institute routinely studies such accidents.
It's possible to design a car to withstand the reported crash speed of 100 mph that ended Diana's life, O'Neill said.
"But that kind of crash is exceedingly rare. It would be foolish to design for that kind of crash because of the trade-offs" in costs and safety that would accompany such a design, he said.
New cars sold in the United States must meet a 30-mph, fixed-barrier crash standard set by the National Highway Traffic Safety Administration. That means unbelted occupants in the car should be able to survive a 30-mph crash into a wall.
That kind of crash is roughly equivalent to a car dropping head first from a three-story building, with each story being 10 feet high, Boehly said. By comparison, Diana's crash was "the equivalent of a 30-story head-first drop."
Designing a car to withstand that kind of hit would require a vehicle body so rigid and heavy it could prove fatal to occupants of smaller cars in low-speed crashes. A super-rigid car could even imperil its own occupants in a moderate crash, at about 25 mph, into a wall or pillar, Boehly and other safety experts said.
Car companies dampen crash forces two basic ways -- by creating front and rear "crumple zones" that allow a vehicle's body to bend and absorb crash energy before transmitting it to the passenger cabin, and by installing lap belts, shoulder harnesses and air bags to help limit the crash forces reaching the cabin.
As a rule, the more rigid the car body, the more energy that is transferred to its interior, especially if the crash is into a fixed barrier. That means a super-rigid car designed to take a severe hit could send more energy to the cabin in lower-speed crashes, because the car's exterior is designed to crumple only at higher speeds, Boehly and O'Neill said.
An unbelted body absorbing most of the impact of a 25-mph hit is just as vulnerable to fatal injury as an unbelted body in a 100-mph crash, Boehly and O'Neill said.
And there is another wrinkle: "Deadly design of the tunnel in which the crash occurred," O'Neill said. "If sections of guard rails had been run along those pillars, it's possible that the car would have hit them with only a glancing blow" and significantly reduced the chance of fatalities.
© Copyright 1997 The Washington Post Company