They’ve become such a familiar modern icon, lending themselves to rock band names and Far Side cartoons, that it’s easy to take them for granted. I’m talking, of course, about crash-test dummies. These robot-like, mannequins with their distinctive black-and-yellow biometric markers are instantly recognisable – but they had to be invented some time. As it turns out, the history of the humble crash test dummy is a pretty weird saga.
The first recorded automobile death was in 1869, when Mary Ward was thrown from a steam-powered car (the internal combustion engine was 17 years away). As cars became more ubiquitous, deaths steadily climbed. Even by the 1950s, some car manufacturers were simply shrugging and saying that nothing could be done to make vehicle accidents survivable, because the forces involved were just too great.
There was no hard data to gainsay that defeatism, so scientists got to work. But how to study the impact of rapid deceleration and crushing impacts on human bodies? The first answer was: with human bodies.
Early experiments were accordingly pretty gruesome stuff. Dead bodies had ball bearings fired at their skulls or were dropped down elevator shafts. Cadavers strapped with accelerometers were put in cars and smashed into walls. Even more horrible, live (and mercifully – sometimes – drugged) animals were used.
But cadavers and animals presented their own problems. Not just ethics and the ‘ick’ factor: a cadaver can only be used once, after all, which made replicating results difficult. Plus most cadavers tended to be elderly males. Using child cadavers was enough to put even the maddest scientist off their lunch.
Some researchers even volunteered themselves. To their credit, they definitely went above and beyond for science. Lawrence Patrick of Wayne State University strapped himself into a rocket sled some 400 times (it made him “a little sore”, he admitted). That was just the start: he and his students volunteered to be hit in the chest with heavy metal pendulums, catch rotary hammer blows to the face and get sprayed with shattered glass.
No doubt they were all relieved when someone finally thought to invent the crash test dummy in the 1960s.
The first dummies were based on ones used by the US Air Force to test ejector seats. An automotive-specific model was designed in 1963 and the first ones were a one-size-fits-all design.
Their first design challenge was to determine the best (that is, median) size for dummy that would be used to test the effects of automotive impacts. Beyond that, they had to determine the ideal shape. The Air Force models had no pelvic structure or spinal articulation. These deficiencies compromised their usefulness in the evaluation of automotive restraint systems where kinematic realism is so essential, particularly with respect to jackknifing and submarining of the body.
In addition to replicating the size and anatomy of a human more accurately, the task force also had to determine the lengths and ratios of various body parts – torso to abdomen to pelvis – as well as the range of motion of limbs and joints.
“Since human beings come in assorted sizes, with a side range of dimensional tolerances for limb lengths,” the engineers reported, “the dimensional specifications of a single anthropomorphic device as representative of a wide population of human beings becomes an abstraction.”
Engineers consulted ‘anthropometrists’ (measuring the human body) and military doctors to come up with a “median” dummy. They added articulation to better replicate the movement of bodies in a crash and built recording instruments in the body cavities.
In 1974, Robert P. Hubbard and Donald G. McLeod described the further development of a crash test dummy head. Cadaver heads were weighed and measured to provide average dimensions (based on an adult male) […]
The resultant dummy heads consisted of an aluminum shell with a vinyl covering that was developed to replicate the friction of human skin. The heads were then tested by dropping them onto a flat surface, an impact test designed to evaluate damage.
However, as feminist philosophers of science began pointing out in the ’70s and ’80s, developing models based on adult males can disastrously skew results for over half the population. That is, women and children.
“Most automobile safety features were designed with the average adult male in mind,” writes [Peter Andrey Smith], which has left children in particular not as well-protected. From an engineering standpoint, the prepubescent body has different mechanical properties, so one goal of the consortium is to make anthropomorphic details in the model account for kid-sized bodies, as well as other variations in sex and age.
Over the next 50 years, though, body models became more sophisticated. Dozens of automakers and research institutes collaborated to build a digital 3-D computer model. The elaborate computer models depict bone, tissue and internal organs from head to toe. Models also branched out to represent humans other than adult males.
And dummies, digital or mechanical, are still shaping auto-safety design.
For instance, in a recent paper funded by Ford Motor Company, [research scientist Jingwen Hu] found that the braking of vehicles with driver-assist technology just before a potential collision tends to alter a front-seat rider’s posture. As a result, the skull tilts forward – which could increase the risk of head injuries. The models could also soon help engineers reevaluate the operation of seat belts and air bags in this new context.
Today, annual motor vehicle fatalities per mile travelled have dropped to a sixth of what they were in the middle 1960s.
For which we owe no small thanks to the humble crash-test dummy.
