breaking auto glass

Rupestris said:
You'd be surprised just how much effort it takes to break a window without the right tool. Putting an elbow through a window is pure hollywood. Especially from the outside.
Click to expand...

I have to agree. It is possible but it isn't easy. Even with a hammer it can be difficult. Also I would suggest wearing gloves if you are going to do this in a non-emergency. While the glass crumbles the amount of force you have to use swinging an object you can still cut yourself pretty good. Don't do this as a test without good gloves on. Leather is OK, something like Ringers are better.

KR
 
During my career as a firefighter I had to break car glass several times. Our city doesn't have high speed highways running through it so I am no vehicle extrication expert but I do have soem real world experience and training. Breaking tempered glass like car side glass or glass building doors is an eye opener. Early one morning we responded to a vehicle accident on Highway 1. I was the engineer and I had my personal flashlight a Streamlight SL-20X aluminum, about the size a 4 d-cell light. I rapped the side window pretty hard and the light bounced off, next swing harder-light bounced off. I played softball for years so I took a swing-for the-fence, light bounced off-shoulder now beginning to hurt. Back to the engine for a pick head axe, light tap with the pick-glass gone.

We also used a technique of swinging a screwdriver while holding it between the thumb and forefinger. Swing very rapidly and hit the glass with the corner of the blade. Most times the glass would break.

Generally when we removed/broke a windshield it was to insert a chain to pull the steering wheel forward and away from the driver. Most often this was started with a "jaws of life" cutter cutting the A-pillar. The cutter cut right through the windshield then we followed up with a glass saw. Sometimes we made a hole, other times we cut away the windshield, and other times we pulled the windshield out of the frame. Newer cars have windshields set with mastic but older cars where the molding could be pulled out the whole windshield would come out. Cliff's method of using a big knife would work but would take a heck of a long time. An axe would be a better choice. Safer too.

Take a look at a big tempered glass door sometime. These doors are around 3/4' thick. I never had to break one but we always joked the if we couldn't go throught the lock or cut the striker then we would ask the cops to shoot it. Our official method was to throw a sledge hammer at it to break it if we couldn't access the lock. Ha! These doors are usually installed on a building with an all tempered glass window front.
 
2dogs said:
Generally when we removed/broke a windshield it was to insert a chain to pull the steering wheel forward and away from the driver. Most often this was started with a "jaws of life" cutter cutting the A-pillar. The cutter cut right through the windshield then we followed up with a glass saw. Sometimes we made a hole, other times we cut away the windshield, and other times we pulled the windshield out of the frame. Newer cars have windshields set with mastic but older cars where the molding could be pulled out the whole windshield would come out. Cliff's method of using a big knife would work but would take a heck of a long time. An axe would be a better choice. Safer too.

Take a look at a big tempered glass door sometime. These doors are around 3/4' thick. I never had to break one but we always joked the if we couldn't go throught the lock or cut the striker then we would ask the cops to shoot it. Our official method was to throw a sledge hammer at it to break it if we couldn't access the lock. Ha! These doors are usually installed on a building with an all tempered glass window front.
Click to expand...


Like I said. I have also been a member of the local fire department for a number of years also. Fortunetly:confused: :D we have an interstate that goes through our town plus the added joy of many back roads with lots of trees so we get to do vehicle extrication quite frequently. I agree with 2dogs that cliffs knife would probably work once a breech was made but if your in a rush, like you have a fire. Don't screw around with the windshield. You only die really, really tired. The proper tool on a side window will work much faster. If you are not in a rush then, just wait for us. Well be there pretty soon with the right stuff. Tools, I mean. :D :o

KR
 
So, can the more knowledgeable tell me whether I am wrong to rely on my axis locked AFCK to do the number on a side window? It seems it would be up to it, but I don't have a convenient car window to legally smash with one to find out.
 
I keep an automatic center punch duct-taped inside the map pocket on the driver's door. If it's in the glove box, you can help another driver, but may you may not get to it yourself if the car is upside down/sideways/who-knows-what. Ditto what others said on tempered glass-- sharp point pressure is the way to go. From outside with no tools, a sharp rock comes to mind.

I've seen patio doors bounce a hammer back when thrown at it, but if you tap the edge (it would have to be out of the frame), you get an instant bucketfull of glass popcorn.

The only way I know how to deal with a windshield from inside is to push it out-- best done with the feet and you may not be able to get in that position.
 
A whip antenna works really well. Might be a good way to go if you are trying to get someone out of a car and don't have anything better.
 
Dale the windshield push works with glass set in the frame with a rubber moulding/weather strip. If the windshield is mastic set you're SOL. Still some sort of effort is better than none at all. I've been to crashes where the windshield is laying on the ground in front of the car, actually an old Ford van, in one piece.

Remember kr1 that they are "tools" not "toys". :D

Boats if you have to use your AFCK to break a window try to flick your wrist and have the top of the point hit the glass at high speed. Glass will fly about so cover and protect yourself and try to have the victim do the same even though you are breakin a rear window. Also, "try before you pry". In other words check ALL the doors to see if they are unlocked.
 
I've read that a spark plug makes a great auto window glass-breaker. I guess the theory is that it lets you combine just the right amount of force and speed on the right tiny section of the glass. Never tried it, though, nor saw it done.

You know, this is really a terminal ballistics question. One factor in breaking brittle things seems to be the speed with which the force of the striking object is transferred to the target. For example, try cradling an ice cube in the palm of your weak hand, and striking it swiftly with the bowl of a spoon held between the fingers of your dominant hand. You'll likely find that a teaspoon shatters the ice a lot better, most of the time, than a much-larger tablespoon. Try it a few times and see if it isn't true. I'm not sure of the physics behind this (Cliff, maybe you can elaborate), but I suspect it's got to do with all of the kinetic energy of the smaller spoon being transferred to the ice in a shorter timeframe, instead of a slower transfer that you get as the larger tablespoon decelerates over a slightly longer period of time. Maybe a similar phenomenon to how a .223 bullet may make a larger hole in a game animal than a .308.

Maybe the physicists on the forum can shed light on this?

Also, another potentially relevant question: is a glass-breaking technique that works when there's air on both sides of the glass going to work the same if there's water on the other side? I could see the glass behaving differently if the car's sinking in a river, than if you're testing it in a junkyard.
 
2dogs said:
Dale the windshield push works with glass set in the frame with a rubber moulding/weather strip. If the windshield is mastic set you're SOL. Still some sort of effort is better than none at all. I've been to crashes where the windshield is laying on the ground in front of the car, actually an old Ford van, in one piece..
Click to expand...

I've watched installers and wrecking yard workers push out mastic-set windshields a bunch of times. The glass generally broke and kind of peeled out of the body. The problem is that they were sitting upright in a dry car and not in danger of dieing. If I could break a side window, that would be my first choice. My point is really that your legs are a lot stronger and the windshield is hard to break. While were's at it, most rear windows are a real bear to get out. Also, in general, the newer the car, the thinner the windshild is. A lot of research has gone into making them less of a head buster and keep weight down as well.
 
Car and Driver magazine did an article about two years ago about the glass breakers you can buy from Auto stores...They look like little hammers and mount in your car somewhere. The author, Patrick Bedard, said they did multiple tests with those little hammers using women and men from the Car and Driver office. After much sweat and effort they found out that the hammers were basically useless unless you were about 6'4" and weighed about 250 lbs. That was the only person who actually broke a side window when the car was set up as in an accident.
 
Return of the J.D. said:
Maybe a similar phenomenon to how a .223 bullet may make a larger hole in a game animal than a .308.
Click to expand...


The kinetic energy equation is ke = .5*m*v*v. This means for kinetic energy if you double the mass of the bullet then you will double the energy. If you double the speed you quadruple the energy.

As far as the 223 and 308 I don't know if this is true. There are other things such as the instability of the 223 after striking a target. Also the higher velocity of the 223 can cause more cavitation. If the cavitation exceeds a certain point then the wound channel is bigger.

There are other things that can come into play but that is some of the physics of it. They made me take physics when I went to engineering school. Bastards. :D ;) Exterior ballistics has been a hobby of mine since I was using a slide rule in 1969 trying to understand Hatchers ballistic tables. I use to calculate them by hand and slide rule. Until 1980 when I got out of the army and bought a TRS80 computer. The first program I wrote was an implementation of the Hatcher tables and would compare my answers against the Speer and Hornady and Lyman reloading manuals. I know. I was an odd kid. I worked in a gun store for 10 years from age 16 on and off until I graduated College.

KR
 
cgjones said:
A whip antenna works really well. Might be a good way to go if you are trying to get someone out of a car and don't have anything better.
Click to expand...

Have you actually done this? You are not talking about the standard metal FM antenna on most cars correct?


KR
 
kr1 said:
Have you actually done this? You are not talking about the standard metal FM antenna on most cars correct? KR
Click to expand...

Assuming I rolled up on an accident and wanted to get someone else out, I'd go for a tire iron, the whole jack, or a rock. A western style belt and buckle would be a better try than an antenna. I can see the concept, but I'm doubful it would work. Great try at improvising though!
 
T-BAG said:
Car and Driver magazine did an article about two years ago about the glass breakers you can buy from Auto stores...They look like little hammers and mount in your car somewhere. The author, Patrick Bedard, said they did multiple tests with those little hammers using women and men from the Car and Driver office. After much sweat and effort they found out that the hammers were basically useless unless you were about 6'4" and weighed about 250 lbs. That was the only person who actually broke a side window when the car was set up as in an accident.
Click to expand...

Good research, reading this post I was wondering about those little tools.
The seatbelt slicer seems like it would worry.

I like the tire iron idea, as you can get the tip speed you need.

But, as was stated, if you are on the outside, looking in, and the FD is on it's way, you may do some real damage to the victim trying improvised methods.
Of course, if the vehicle is on fire, the Injury Risk vs. Car-B-Que Risk makes your decision for you, try the kitchen sink if you have one.
 
Actually, it'd be faster and safer to use the Glock as a hammer. Makes a bigger hole in less time.

You can't extricate somebody out of a 9mm-wide hole.

Unless Fespo thinks shooting the window makes it explode like sugar glass?
 
You must log in or register to reply here.
Back
Top