Well, like I said, I was actually there in a school that does this, and the windows open fine. And it was with a manual crank. I witnessed it over and over with my own eyes. So I have no idea how Mythbusters came to a different conclusion. ETA: Although this was with a partially submerged car. This wasn’t with a fully submerged car, if that makes a difference. This is opening the window as the car is on its way down.
What about batteries, board games, an umbrella, or a dutch oven? I’m just wondering if I need to buy one of those fancy hammers or if I’ll be good with what I’ve already got in my car.
Yes, on Mythbusters the car was fully submerged, but there was still air in the car. Until the inside of the car filled with water the windows or doors couldn’t be opened because of the pressure differential. If your car goes in the water you probably won’t be able to open the doors, but if you can get the window open BEFORE water gets up to the windows that’s possible. It’s only once water gets up to the windows that you can’t open the window.
Mythbusters assumed that the window was completely submerged. If the car hasn’t yet gone down, you might even get the door open.
You keep a dutch oven in the car?
They didn’t test every possible item that a person might carry.
Kicking with heavy boots, or hitting with keys or cellphone didn’t work. I’m going to guess that board games, batteries, and umbrellas aren’t going to fare much better.
The little emergency hammer did work though.
Ah. I see. The school was actually teaching the method of opening the car door once the car was fully submerged. (From the story: “at Ricas they want you to experience the worst: the submerged, door-opening escape.”) Most of the students did not have the patience to explore that option and just went with their instinct to go out the window. The water needs to get nearly fully in the car before the doors will budge. I think the day we went, of the six students, 2 made it to the door stage, and four went out the window. The author of the story seems to imply that he was the only one that panicked and went out the window, with everyone else doing the proper door escape, but that is not my memory at all. Maybe 3 made it to the door stage, but he wasn’t the only one to scoot out the window.
Here’s a pretty decent video of a windows-rolled up, door-opening escape. (He escapes when the water is about 7/8ths up the car though. At the Ricas Driving school, they did it fully submerged.)
I infrequently go camping during the summer and I don’t use a dutch oven when I’m home and I’m horribly lazy so it often ends up in the back seat for months on end.
I think what’s required to get the tempered glass to shatter is a sharp impact from a very hard object, on a very small area, which is why the hammers come to a point. They also sell this kind of thing, which is basically a spring loaded punch. So shoes, board games would be useless, a battery probably would be as well, a full size umbrella that comes to a hard point might work, and a dutch oven would probably work fine as long as you used the edge, not the side or bottom.
An episode of Top Gear (UK) also covered this with a VW Golf submerged in a pool—
gist: try to get out as soon as possible via the door or windows before your electrical system shorts out.
I imagine a clip of this episode is available on youtube.
I found the Top Gear episode online. Here’s the relevant part. The way they did it, it took time for the pressure to equalize enough to get the door open once the car was fully submerged. I assume that must be why at that driving school, they tell you to open the window straight away, as it must equalize the pressure more quickly (as I observed.) The people who did the door escape were pretty much able to do it within 5-10 seconds of the car hitting the bottom of the pool.
Adam tested this in the shop—not underwater—by placing sandbags and metal weights on a car window that was positioned horizontally. It seems to me that friction from the weights was contributing to the inability to open the window. During the test with the power window, there’s a close shot where you can see the window moving slightly, then stopping when the weight touches the door frame.
All this “proved” is that you can’t open a car window that has sandbags and barbell weights piled on it. Water on glass is obviously going to have a lower coefficient of friction. I was astounded that the Mythbusters tested it this way.
I just checked the episode on Netflix to verify that I was remembering this correctly. The test starts around the 28-minute mark.
Mythbusters has never been known for ‘rigorous’ testing.
The problem isn’t hardness or weight of the striking material. Underwater, you can speed you can kick or punch at is greatly reduced, and windows are pretty tough to begin with.
The striking hammer is small (and, therefore, rather light) but it’s striking surface has a very sharp tip so all the force is focused on a single point. On plate glass, it would only poke a small hole. But on tempered glass that small hole causes the entire pane to shatter into many small (and relatively blunt) pieces.
You might be able to get a similar result using a screwdriver like a chisel (with your other hand as the hammer), but I doubt it. Drag from water will still seriously slow your punch (and, thus, the force imparted to the screwdriver). The striking hammer is narrow along the axis it swings, plus, and the handle adds a bit of leverage beyond a slow-moving fist.
Metal on the glass will help the glass to crack then the pressure causes it to break.
Small pressures create forces over large areas. Assume a window 2 ft by 1.5 ft. that is 432 sq inches. If the window is down 10 feet the pressure is in the 5psi range. the total force on the outside of the window is over 2000 pounds.
A person can not kick hard enough to over come that force. But if you crack the glass it will implode.
I bought mine here:
Other places sell them too. I haven’t tried to break glass with it, but it does a fine job dinking steel to keep drill bits from walking about. One point about them: if your car is moving anyhow but smooth and level, things won’t be where you put them, not even in a glovebox (many are open to the underside of the “dashboard”), and if the car flips, things scatter, you won’t find them in murky water. Keep things secured where you can reach them, especially the seatbelt cutter and flashlight. Altho i once swam face-first right into the mud even with a huge superbright flashlight in one hand, but it did point to the surface when i let it, and it was useful once i got to the surface. Don’t discount a grocery bag full of air while you are waiting for the waterflow to stop.
After the episode I saw today where they took the powder charge from a shotgun shell and referred it it as “black powder” I hope everyone will excuse me if I don’t believe anything that myth busters say they have “tested”.
Getting back to the actual test, water on the window run channel will act as a lubricant making it easier to slide. Also the water pressure will be evenly distributed all across the window surface not so with sand bags.
If you have a head on collision your dutch oven may well kill you or your passenger.
Why does nobody use the sunroof? Is it less breakable? My goal if ever in this situation would be to try to open the sunroof before the electrical shorts out and get out that way (or at least get more air).
If you can get the sunroof open, go for it. But if it’s broken, the way the glass is sealed around the edges tends to keep a lot of jagged edges in place that will slice you head to toe. Here’s a typical example. It’s better than drowning, but doesn’t make a good plan A.
That’s tempered glass. Hit what remains and it will crumble into small pieces.
Here is my going into water plan
- Hit open on Sunroof if it opens fine. If not
1a. Hit auto down on both front windows - Move steering wheel as far forward and up as possible
- Move seat to the rearmost position if sun roof is open release seat belt and climb out if not
- recline seat fully
- Seat belt off
- Climb into rear seat and wait for pressures to equalize open rear door and leave.