Hybrid III, his cousin Euro SID-1, and offspring P1½ and 3 are dedicated to discovering what happens to victims of serious crashes. Here's what they do:
Hybrid III (top right) and EuroSID-1 (bottom right) have experienced dozens of crashes first-hand. Their role is vital: many of the accident simulations reported on the following pages rely on having a driver and passenger aboard to provide a picture of likely injuries in a crash, although the pedestrian safety tests use simulated limbs to chart what happens in a collision.
Hybrid and EuroSID-1 are no ordinary driver and passenger, mind: these are steel-skeletoned, rubber-skinned dummies packed with sensing equipment. For the front impact, a dummy called Hybrid III sits belted at the steering wheel. In size and weight, he is Mr Average, but adjustments to the information provided are made to take account of different driver sizes.
The version of Hybrid III used by the Transport Research Laboratory is of the type that is becoming the standard crash test dummy worldwide. He was developed in the U.S. for airbag research, but has evolved to provide a greater variety of crash information.
Hybrid III's cousin, EuroSID-1, was purpose-developed in Europe for side-impact testing. Except for the head, his instrumentation is different. There are also child-size dummies, P (for Pinocchio) 1½ and 3, which are involved in frontal- and side-impact testing. They are of the size and weight of a typical 18-month-old and three-year-old. In each test, they sit in seats recommended by the manufacturer for each car tested, and they are installed on the car's rear seat. In frontal impacts, P3 sits behind the driver, his younger brother behind the passenger but the two swap places for side-impact testing because only the younger carries full instrumentation.
Inside each dummy is a rigid skeleton that mimics parts of human bone structure. For testing, the dummy's rubber flesh is clothed to reduce friction. The sensing devices they contain are wired to recording equipment carried in the rear of the cars during testing.
Occasionally a dummy will emerge from a crash with cuts, but extensive damage is rare - which is just as well, since each can cost up to £100,000. But while the dummies are tough, much of the equipment they contain is extremely sensitive, so much so that the dummies' temperature must be monitored. If they get too cold or too hot they could give inaccurate data so, if necessary, they are kept warm. After every few tests, every dummy is examined and re-certified. Below, we explain how they "learn" more about a crash than any human test-driver ever could...
Dummy Anatomy (limb by limb)
The head is made of aluminum and covered in rubber flesh. Inside, three accelerometers are set at right angles, each providing data on the forces and accelerations to which the brain would be subjected in a crash.
Features measuring devices to detect the bending, shearing and tension forces on the neck as the head is thrown forwards and backwards during the impact.
Neither arm carries instrumentation. In a crash, arms flail and, although serious injuries are uncommon, it is difficult to provide worthwhile protection against them.
Chest (front impact)
Hybrid III's steel ribs are fitted with sensing equipment that records the deflection of the rib cage in the frontal impact. Injuries result if forces exerted on the chest area, such as from the seat belt, are too great.
Chest (side impact)
The side-impact dummy, EuroSID-1, has a completely different chest, with three ribs instrumented to record compression of the chest and velocity of this compression.
EuroSID-1 is equipped with sensors to record forces likely to cause abdominal injury.
EuroSID-1 has instruments fitted in its pelvic girdle. They record lateral forces that may result in fractures or hip-joint dislocation.
In Hybrid III, this area is made up of the pelvis, femur (thigh) and knee. Load cells in the femur provide information in frontal impact tests on likely injury to all sections, including the hip joint which can suffer from fractures and dislocations. Instrumentation called a "knee slider" is used to measure forces transmitted through the dummy's knees, particularly if they hit the lower facia.
Instruments fitted inside the leg measure bending, shear, compression and tension, allowing injury risks to the tibia (shin-bone) and fibula (bone connecting knee to ankle) to be assessed.
Feet and ankles
Assessment of feet and ankle injuries is based on how badly the car is damaged, by measuring distortion and rearward movement of the driver footwell area.
Engineers check that Hybrid III is sitting in the right position and at the correct angle.
Engineers fit dummies into child seats recommended by car manufacturers.
Dummies' recording gear sits in boot. Fuel tank contents drained, then replaced with water.
Renault Laguna hits barrier at 64kph (40mph). Crash recorded by still and video cameras.
The airbag has gone off, but how bad was the crash? Hybrid III dummy provides many answers.
Rescued from the wreckage. Paint on face and knees pinpoints any contact with wheel and facia.