Believe it or not, at one time it was considered a safety feature to have the windshield pop out in a car crash. A 1955 Popular Science survey showed that 87% of people would want a pop-out windshield in their vehicle. This circa 1970 BMW threw out its windshield when it hit a tree in a human crash test at around 25 mph.
Most cars never adopted pop-out windshields, and by the late 1970s, the pop-out windshield idea was dead. Federal Motor Vehicle Safety Standard (FMVSS) 212, enacted in 1976, required windshields to maintain 75 percent of their attachment in a 30 mph full-frontal crash test (if a vehicle had "passive restraints", such as airbags, the requirement fell to 50 percent). Pop-out windshields, by their very nature, have 0 percent attachment and as such are a clear failure under FMVSS 212.
Effectively, pop-out windshields were banned beginning in 1976, at least in the USA. One might wonder "if I wear my seatbelt, what does it matter if the windshield flies out?"
The stunt driver of that BMW better be glad that a branch from that tree didn't crash down onto the car. Windshields are typically made of laminated glass (that ancient Bimmer's was made of tempered glass) that provides a degree of protection from outside debris.
The windshield protects the occupants from the hood, which in a sufficiently severe crash, without airbags, even seat belted occupants can strike.
The windshield can protect occupants from hot steam coming from a damaged engine. In the BMW's crash test, it's easy to see the hot steam coming into the occupant compartment.
What if the seat belt breaks? It's much better to crash into a windshield than be ejected.
If the vehicle rolls over, the windshield provides vital support for the roof structure and can help preserve survival space.
It's a bit surprising seeing a company like BMW using pop-out windshields as late as the 1970s. It is not known when BMW ceased to use pop-out windshields, but it is presumed to be 1976 or earlier.
I have seen a van crash test from as late as 1988 where the windshield popped out; although cars, pickup trucks, SUVs, and even buses were covered under FMVSS 212, "forward control" vans (where the driver sits atop the front axle) were not covered.
Most cars never adopted pop-out windshields, and by the late 1970s, the pop-out windshield idea was dead. Federal Motor Vehicle Safety Standard (FMVSS) 212, enacted in 1976, required windshields to maintain 75 percent of their attachment in a 30 mph full-frontal crash test (if a vehicle had "passive restraints", such as airbags, the requirement fell to 50 percent). Pop-out windshields, by their very nature, have 0 percent attachment and as such are a clear failure under FMVSS 212.
Effectively, pop-out windshields were banned beginning in 1976, at least in the USA. One might wonder "if I wear my seatbelt, what does it matter if the windshield flies out?"
The stunt driver of that BMW better be glad that a branch from that tree didn't crash down onto the car. Windshields are typically made of laminated glass (that ancient Bimmer's was made of tempered glass) that provides a degree of protection from outside debris.
The windshield protects the occupants from the hood, which in a sufficiently severe crash, without airbags, even seat belted occupants can strike.
The windshield can protect occupants from hot steam coming from a damaged engine. In the BMW's crash test, it's easy to see the hot steam coming into the occupant compartment.
What if the seat belt breaks? It's much better to crash into a windshield than be ejected.
If the vehicle rolls over, the windshield provides vital support for the roof structure and can help preserve survival space.
It's a bit surprising seeing a company like BMW using pop-out windshields as late as the 1970s. It is not known when BMW ceased to use pop-out windshields, but it is presumed to be 1976 or earlier.
I have seen a van crash test from as late as 1988 where the windshield popped out; although cars, pickup trucks, SUVs, and even buses were covered under FMVSS 212, "forward control" vans (where the driver sits atop the front axle) were not covered.
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