Intersection Collision (1964)

[Music] intersection collisions are double impact events the first impact is between two colliding structures the second impact occurs when the motorist strikes the car's interior or are thrown outside the car for the first impact fractures such as speed weight and point of impact determine the structural deformation of the vehicles structural design also affects collision performance for example these wider and lower 1960 vintage automobiles show markedly increased stability against rollover compared with cars of 1950 vintage also with the modern cars lower profile the strut cars tendency to roll over by the weight car bearing however the passenger compartment is more vulnerable to intrusion by the striking car the center door post structure is one way of reduce intersection collision injury during motorists experience deceleration forces like those in a severe fall at quite moderate speeds the forces of collision are of such magnitude that even motorists restrained by lap belts suffer involuntary killeen with car's interior Strutter virgin earring has majored these forces during a series of experimental collisions by post Christ data analysis the injuries to motorists for various speeds and points of impact can be estimated in the striking car 20 mile per hour front side impact the driver's head sustains a 20 G impact a blow of some 500 pounds from the unrestrained three-year-old 20 mile per hour centre side impact the child strikes the passengers head with a 22 G 30 mile-per-hour frontside impact in spite of the lap belt the drivers chest hits the steering wheel with a force of 3,000 foot-pounds 30 mile per hour centre side impacts the drivers lap belts load to 1600 pounds the unrestrained children in the striking car survived all these moderate speed collisions but sustained head injuries contusions and multiple abrasions over the entire body the driver who wore a lap belt also survived each collision but sustained head and chest abrasions puncture wounds and probable fractures to the skull and rib cage the front seat passenger wearing a lap belt and shoulder strap the so called three-point belt sustained only minor abrasions and lacerations in the struct car during an intersection collision motorists receive direct collision forces from the striking car drivers are pinned against the side until the car has reached full lateral acceleration then thrown in the opposite direction front seat passengers move forward as they move toward the struck side these motorists are restrained by the same devices as those in the striking car drivers lap belts passenger three-point belts children unrestrained twenty mile per hour front side impact after receiving a 47 g shock the belted driver's head is forced through tempered glass injuries face lacerations and abrasions survive 20 mile per hour centre side impact the driver's head registers a 50 g blow against the tempered glass 20 mile per hour rear side impact the unrestrained three-year-old is battered against the interior bilateral collision forces multiple abrasions over entire body and face survived 30 mile per hour frontside impact although the drivers lap belt low to only 150-pound his head receives a 1,000 pound blow multiple abrasions and lacerations survived 30 mile per hour center side impact the front seat passenger with the three-point belt as in the previous impact sustained only minor abrasions and lacerations in this 40 mile-per-hour frontside impact no seat belt for you the driver striking the steering wheel and columns sustains a 60 g peak chest load crushing his rib cage and producing multiple abrasions to his face left shoulder and left and right legs the passenger strikes the drivers chest a 15 g blow pushing him against the left side door with his head outside the shattered window the driver now sustains lacerations abrasions punctures and a fractured ankle driver unrestrained probable fatality pinned by the accelerating forces from the striking car and the unrestrained passenger a drivers chances of survival at speeds of 30 miles per hour and above are slim in the striking car the abrupt change in direction of collision forces RAM the unrestrained passenger against the door the moving weight of the front seat torn loose from his Anchorage combined with out of the unrestrained motorist / stresses the door latch mechanism the latch failure permits the ejection of the passenger he sustains a 24 g chest blow on striking the pavement and a deep laceration laying open the right side of the skull he comes to rest 33 feet from the point of impact passenger unrestrained fatality seatbelts have definitely reduced the hazard of motorists ejection when an overstressed door latch mechanism fails however though the motorists would lap belts are kept from being thrown out of the car their heads and shoulders still strike the car's interior even in the moderate 20 to 40 mile-per-hour collisions under investigation combination shoulder strap and lap belt the three-point belt will reduce the head and chest injuries from intersection collision also under study at the University of California is the often overlooked problem of how best to restrain children against the effective collision forces the preliminary investigation has established that spatial restraints must be provided for infants and child protection in this 30 mile-per-hour rear side impact the unrestrained bassinet nearly ejects the infant to provide suitable protection during intersection collision bassinet must be aligned with the car's long axis and securely tied down the seated three-year-old is thrown violently forward in this 40 mile-per-hour collision while in this 40 mile-per-hour collision the child is held in a safe position by her harness aside from evaluating passenger restraining devices these collisions provided a basis for safer structural design the increased capacity for doors to remain lat even when overstressed and partially sprung is an improvement common to newer automobiles but when seats tear loose and combine their inertial load with that of unrestrained motorists against the door latch failure is still common seats must be designed to withstand much greater loads moderately severe collisions will develop seat inertial loads in excess of 20 G's seats should also be structured to function as a passenger protective restraint during impact further research is underway to evaluate the relative merits of different types of safety glass we now know that most motorist injuries are avoidable through information gained from these controlled collisions engineers are improving the christ' safety of automobiles by revising the structural design and when motorists wear the seat belts now standard in most cars they have the most effective step now possible in the reduction of accidental injuries [Music]