Bulletproof glasses are widely used to protect important personalities around the world. While most of us may not have seen a bulletproof glass till now, but they are made up of multiple layers of glass and are really thick. But are they really strong enough to stop objects other than bullets? Well, here is a video that shows a Mahindra Bolero, a Massey Ferguson tractor and a Toyota Fortuner taking turns to go over the glass. Here is the result.
The glass used here is a 50mm bulletproof glass, which means it has a thickness of 50mm. The glass seems to be taken from the windshield of a discarded vehicle. It has the rubber sealant boundary all around.
To test the strength of the glass, the Mahindra Bolero goes over it first. Well, the Bolero weighs somewhere around 1,600 kg. The ride-side wheels of Bolero goes over the glass and leaves it scratchless. There is no sign of any damage in the glass.
After the Bolero, the tractor goes over the glass. The front-wheel does not make any impact but for unknown reasons, the driver of the tractor was driving it by applying the brakes. When the rear tyre got on the glass, it developed a few cracks in the middle layers. The tractor weighs about 200 kg more than the Bolero. In the end, the Toyota Fortuner goes over the glass and shatters it completely. It should be noted that the Fortuner weighs more than both the vehicles that passed over the glass earlier. It weighs around 2,200 kg.
It should be noted that the weight mentioned of the respective vehicles above did not put all the weight on the glass. The weight of most vehicles are equally distributed on all the four tyres and only tyre was on the glass at one time.
Bulletproof glass strength
Bulletproof glass is made using multiple layers of laminated glass. More the layers, better the protection. There is a thermoplastic layer between the glass that absorbs the pressure and ensures that the glass remains safe. There are many other things that go in the construction of the bulletproof glass but this is the basic idea. This is why when a bullet hits such a glass, it creates an impact that is absorbed by the layers of thermoplastic and the glass itself. Even if the outer layer and middle layers of the glass crack, the bullets do not damage the base layer, which keeps the occupants safe.
Bulletproof glasses are also classified according to their strength. If a bulletproof glass is rated to stop a bullet of .22 calibre, it will have less number of layers compared to the glass that is rated to stop a bigger .357 calibre bullet. Also, if two bullets hit at exactly the same spot on the glass, there is a chance that the bullets can breach the layers and enter the opposite side. However, since most of the time the vehicles with bulletproof glasses are secured by other cars, it is quite a rare occasion to see such things. Bulletproof glasses are also extremely heavy compared to the regular laminated glasses.