MythBusters Episode 72: Underwater Car
Air Date: January 24, 2007
If a car falls into the water and becomes submerged, you cannot open the door until the interior is flooded.
confirmed
The pressure differential between outside and inside when the car is submerged is too great for a man to force the door, and the pressure must first be equalized, which means the interior must be flooded first. But it should be noted that Adam was forced to resort to emergency air in his first test. A second test later showed it to be possible to escape the car simply by opening the door, but only by remaining calm and not attempting to open the door until the interior is well and truly flooded, so as to conserve oxygen while holding your breath.
You can escape a car that has fallen into the water immediately after hitting the water.
confirmed
There is not enough water pressing on the door to keep it shut. Adam escapes easily.
You can escape a car that has fallen into the water as soon as the water inside the car is up to your waist.
confirmed
Adam barely manages to force the door open and is even briefly submerged before he emerges from the car.
You can escape a car that has fallen into the water as soon as water covers the car window from the outside.
busted
At this point, the pressure differential has become too great. Adam is unable to escape.
You can open a window in a submerged car by using a manual window crank.
busted
Using a test weight of 350 lbs (equivalent to pressure differential from just two feet of immersion), the pressure of the window glass against the frame is so great that no amount of effort can move the gear. You are more likely to break the window handle.
You can open a window in a submerged car by opening power windows.
busted
Though more powerful, power windows still cannot overcome the pressure differential. Contrary to popular belief, though, power windows can withstand immersion in fresh water for prolonged periods and still function.
You can open a window in a submerged car by attempting to break the window using a set of keys.
busted
Window glass is tempered and resistant to impact from blunt objects. Keys are ineffective.
You can open a window in a submerged car by attempting to break the window using a cell phone.
busted
A cell phone is ineffective.
You can open a window in a submerged car by attempting to break the window using steel-toed boots.
busted
Boots are ineffective.
You can open a window in a submerged car by attempting to break the window using a window-breaking hammer.
confirmed
The device is designed with a pointed tip designed to shatter tempered glass. The hammer breaks the window on the first try.
You can open a window in a submerged car by attempting to break the window using a spring-loaded center punch.
confirmed
The point of the punch can work like the tip of the hammer, and punches are sold for the purpose of breaking window glass. The punch breaks the window on the first try.
A piece of paper cannot be folded in perpendicular halves more than seven times, regardless of its size.
busted
It was impossible to fold a piece of letter-sized (8.5" x 11", 216 mm x 279 mm) 20 lb (37 g/m2) copy paper with perpendicular folds more than seven times. The thickness of the paper exponentially grew with each successive fold, and after the seventh fold the paper was just too thick to fold without breaking. The MythBusters then laid out a football field-sized sheet of interconnected paper (170 ft x 220 ft, 51.8 m x 67.1 m), and due to the reduction of its thickness-to-area ratio, were able to perpendicularly fold the paper 11 times.
Newer: Episode 73: Speed Cameras
Older: Episode 71: Pirate Special
“A piece of paper can be folded in perpendicular halves more than seven times, regardless of its size.” – Busted.
That shoudl read, “A piece of paper can *NOT* be folded (etc.)”.
June 23, 2007 at 5:48 AMTrue, thanks. The wording on that myth has been clarified.
June 23, 2007 at 2:31 PMHi there going back to submerged car, the pressure differencial in water is not preventing the window from moving because the window is smooth. when you tested the theory you put weights and sand bags onto a car window in a door on its side therefore the weights and sandbags will not move pass the window frame. You really need to test it on the car in a pool. sorry not being picky but gotto get it right i suppose.
July 22, 2007 at 1:39 PMhe also didn’t use the point of the keys, which would mean less force would be required in order to break the glass, just like the hammer and such.
July 22, 2007 at 2:15 PMalso on a safety note, adam didn’t blow bubbles on his way up from the car, which could have killed him due to the expansion of air in his lungs. jamie being a “dive master” should have known this, to me that was the most disturbing thing i saw in this episode, after all if the diferential pressure wasn’t as great (as in if the myth was busted) then the air in the car would have been compressed enough to pop his lungs from about 6 feet (i beleive 4 feet is the record).
I thought the same thing about using the point of your keys. It seems like if you use anything to concentrate the force like the hammer or pick does, the tempered glass will shatter. Kicking or punching the window won’t work because underwater there is too much resistance to move your arms or legs fast enough, and a boot will disperse the force a lot more.
July 24, 2007 at 1:29 PMAfter the Bridge collapse in Minneapolis yesterday this episode seemed to be a bit more relevant. Is there any particular type of window breaking device that works better than the rest (Hammer vs. Spring loaded center punch)? For some reason the spring loaded center punch doesn’t seem as dependable. How about Seat Belt cutting devices in the event it jams or your weight is preventing it from releasing?
August 2, 2007 at 9:58 AMSee lifehammer.com and resqme.com
August 2, 2007 at 4:17 PMAlso found spring loaded center punch recommended for first responders on web site. But the lifehammer and resqme products have seatbelt cutters included. Spring-loaded center punch does not.
August 2, 2007 at 4:19 PMI found this site through a google after the bridge collapse. If I have a life hammer, I can get out but how would you do it if you had kids in the back? Esp. one in car seat?? I imagine that if you bust the glass, the car would flood with water very quickly. I’ll have to find this episode on iTunes.
August 3, 2007 at 11:44 AMJames,
Get the kids out first.
August 6, 2007 at 9:34 AMHi all, being an Australian and living on the driest inhabited continent in the world makes me wonder why you people like to drive into water so much. It would seem perfectly logical to stay the hell out of it if you where in a car.
August 11, 2007 at 12:35 AMPretty worrying about the standards of your seat belts to. Ours always work even in 30 year old cars.
Being a EMT I know that seatbelt buckles when your in a panic can be hard to work. It’s best to have a seat belt cutter included. Please note, not wearing a seatbelt the impact of your nogging into the windshield would leave you useless. I agree to have kids in hand, cut the seat belt a second time so you have enough to tie your child to you before you attempt to break out. Try not to panic, you will have time to get out and get to the surface for your next breath.
August 14, 2007 at 3:42 PMAdam, and J man, you guys did not test the windshield. If you it the windshield during a (superhuman) panic with the heal of your foot, you can break the windshield. (Foot or boot, or shoe)
August 14, 2007 at 10:31 PMSide door windows can be broken with your elbow, at least from the outside, on dry land. I saw a thief do it right in front of me. The window broke on his third strike. Then he stole the purse from the front seat and ran.
August 20, 2007 at 11:43 AMWith reference to submerging a car in water and being able to opent he car door submerged.
I Have seen this experiment undertaken by TopGear; a vehicle program on the BBC.
They found that while the car was sinking the pressure did not equalise until it had reached the bottom and rested for a few moments.
They indicated that as some lake/lochs can be quite deep in Britain and holding your breath until this process had completed would make survival unlikely. The best cause of action was to get out asap, before the doors became submerged.
August 21, 2007 at 6:49 AMI was an autoglass installer for 11 years and can tell you that a door glass can be broken with a set of keys by rubbing them firmly in one place. deepen a small scratch and the temper will do the rest. I have done it in the dumpster at work just for fun with used windows.
August 24, 2007 at 7:51 PMHello from Australia! We were wondering about the effects of salt water on the electrical system of the car. Would the salt water short out the system more quickly than fresh water? We also have to agree with kevin from the u.k regarding the weights on the window. Lets repeat the experiment with a car with electric windows in both fresh and salt/sea water. please. We love your show, keep up the great work guys!
September 10, 2007 at 6:04 AMHello from Sweden! I think that the mythbusters have missed a possible tool for escaping a sinking car, namely the seatbelt latch plate (the metal plate that you push in to the seatbelt mechanism)! It’s always where you can find it and if you close your hand around the plastic covered back part and let the metal part stick out through your fingers, you can use it as a glass breaking device! I wish I could get the busters to try that!
September 30, 2007 at 11:20 PMYou busted the paper myth on a technicality. The football sized sheets you used were taped together changing the properties of the paper. Increasing the size without increasing the thickness is also unfair. The original myth refers to a standard sheet of paper. With the way you tested it you might as well have used tissue paper.
October 10, 2007 at 1:44 AMI just lost a friend who was unable to get out of a submerged rollover in water. I am researching this subject and have a post on the Halfbakery regarding this subject. Lots of good advice here, thanks.
I’ve heard that they’re beefing up windowglass to make theft harder. If this is so then a lot of this advice will not work.
November 15, 2007 at 8:19 PMin your show “underwater car” you busted the mytin wich you can open a window in a submerged car by attempting to break the window using a set of keys, but you’ve made the attempt to break the window, with a submerged door thou, in a real car when it’s underwater and the interior it’s not filled with water the presure on the window can cause it to break more easyli when hitting it with a key, so I think that you should try it again.
November 22, 2007 at 4:56 PMOkay Adam, I’m late to b**ch (saw a repeat)! However, when you tested rolling down a window (powerd OR NOT), you forgot about friction! TEST IN WATER!
November 26, 2007 at 12:15 AMIloved this episode
January 10, 2008 at 10:48 AM“Taylor L.:
Adam, and J man, you guys did not test the windshield. If you it the windshield during a (superhuman) panic with the heal of your foot, you can break the windshield. (Foot or boot, or shoe)
August 14, 2007 at 10:31 PM”
I agree. Although I doubt it would have a difference, in a panic I’d be smashing at my windshield as though my life depended on it. Lol.
January 15, 2008 at 3:28 AMBlew it on the window thing, folks. EITHER you have differential pressure, OR you have water in the car slowing your hits. Not both. So, if there’s water in the car, roll down the window because there’s no diff pressure. Otherwise, hit the window.
January 30, 2008 at 11:55 PMReally should have caught this, guys.
On the power windows problem, Kevin is right. You could see in your video that the weights against the frame were preventing it from moving, not merely the pressure. Both were probably at work, but I think the power window might have opened without the frame interference.
Brian (Jan. 30) makes a good point about water pressure. But we already know if you wait until pressure equalizes, it’s too late. The question is, can you open the window before you can open the door?
And, as some suggested, you can probably more easily break the window win the pressure is not yet equalized. But do you really want bits of glass pushed into your face by 300 pounds of water pressure?
tom
January 31, 2008 at 1:03 AMI accidentally discharged one of those pointed window punches while holding the thing in my hand, with my thumb over the pointed end. It didnt hurt. I doubt its ability to break glass if it couldnt even puncture the soft skin on my thumb! I’d just get the metal seatbelt buckle (since its always readily available) and punch the window with it.
February 3, 2008 at 7:58 PMFor those of us who have had someone we know suffer this tragedy it is good that all avenues of this myth be tested and the public informed. An episode like this took place right near our home and on a road that we travel often. We still shudder when we pass the spot.
February 4, 2008 at 4:39 PMI watched an episode on “Daily Planet” where they interviewed a scientist studying this topic and his instructions were to exit the vehicle as soon as possible. He estimated that if it was not done in the first 90 minutes, that the outcome would almost always be tragic.
Car industries should get involved in this as well. Maybe making those little bottles, Adam had as backup air, affordable and accessible to the public would be a good idea.
Keep Busting!
Namarie an si
Lance
for jamoecw, its true about blowing bubbles on the way up, but thats if you are breathing compressed air from a scuba tank. if you take a breath of air at the surface and dive down, your lungs compress as the pressure increases. since you are holding the same air as on the surface, your lungs expand back to normal size on the way back up. hence freediving. IF you breathe from a scuba tank at depth, your lungs return to the size they would be at surface. this is where it can get dangerous. as you ascend, air expands. after breathing compressed air ,if you ascend and hold your breath your lungs will over expand and potentially pop (bad). also after breathing compressed air and ascending too rapidly, you could cause an air embolism or DCS.
for lance, pony bottles (the little bottles of back up air) are available to the public, but because of the aforementioned potential dangers, as well as other things to keep in mind, you really should get scuba certified first. scuba diving is a lot of fun, and easy to learn.
November 30, 2008 at 2:28 AMGo for the side windows, which are tempered glass (shatters into not-very-sharp fragments) – NOT the windshield (which has tough flexible plastic sandwiched between glass). The windshield deforms but still traps you in the car.
March 17, 2009 at 7:04 PMI am with Fred E. It was quite obvious that the weights on the car glass window were hitting on the bottom of the window and the friction was stopping it from moviing. If this were done with water there would be no hitting from this.
May 15, 2009 at 7:31 PMCheers.
I too, am thinking about getting the children out. Being a mother with 4 kids I usually have 3 belted in the back and one in the front. If I got out but couldn’t save my kids I would rather be dead too. So, how do you get everyone out safe?
August 23, 2009 at 11:25 AMJust a comment on the power windows myth.
If I remember correctly, they used weights to simulate the pressure of the water pushing down on the power window. The power window was not able to open because it would need a great deal of force to slide the weights sideways due to friction.
I hope Mythbusters revisits this myth.
November 15, 2009 at 5:08 AM1) As water pressure increases and water infilitrates the vehicle, if there isn’t a good escape route, the air will be compressing. So, if you are breathing this air and then exit the vehicle, one would imagine there is a chance of a problem.
On the other hand, you’ll have no real chance to tell if the air is escaping or compressing. Also, since it takes 33′ (10m) to generate 1 ATM of pressure differential (in freshwater), if you’re only down 3-4 m, you’ll probably be okay in any event. And even if you did suffer some damage because you held your breath after breathing some compressed air and came up from a notable depth, you’d still be better off than drowning as long as someone could adminster oxygen and they could get you off to a hyperbaric chamber soonish.
Still, it won’t *hurt* you to slowly exhale a small stream of bubbles as you ascend. Small bubbles, slow stream to give you time to get to the surface.
2) The lifehammer and other similar things work on the idea of force applied over surface area of application. They apply very large forces/unit area because of the sharp point of their delivery. Keys might work, but try punching a board with your keys point out. It’ll probably do your hand some damage. Better to have a reliable rescue tool. At $15, you can’t really argue against the value if you ever need it.
3) To be safest, get some training from your local FD or paramedics on vehicle extrication. Hard to practice if the use of the tool cuts belts and smashes windows, but you should practice unbelting, acquiring the tool, and the rough motions with the eyes closed. Extricating yourself through a window could be challenging for some if they are short like me and fit tightly into place – I’d want to tilt the steering away and move the seat back if possible.
Getting out through a shattered window is a bit like a wet exit in a flipped kayak and that’s a bit exciting if you’ve never done it for real before.
4) Seatbelts, if you are hanging upside down or they’ve taken some damage, may jam. You might not be able to unbuckle, thus trapping you and/or preventing you using the seat belt as a hammer. Something like the lifehammer or resQme should be within *arms reach while belted*. Then you can cut away (probably that would be exciting if you’re upside down also… fall on head on car roof in confined space won’t be fun, but it will be necessary).
5) Pressure outside from water is both good and bad. More of it means likely more water pushing into the vehicle from any point it can intrude (eventually any seals will fail). But it also means that the pressure on a window to fail is greater, so a smaller crack in the glass should yield window disintegration. Of course, the more water pressure, probably the more cold (from depth) and force (in your face) you’ll face when the window goes. Nothing like being kicked in the head by a wall of water… so get out sooner rather than later. But if you have no option and are submerged, probably face away from the window, put your chin on your shoulder to stabilize your head, and shatter the window. That’s the best chance of not getting knocked out or stunned by an inrush of water at significant depth I’d imagine.
6) If all else fails, try keys, try seat belt edge, if you’ve got a brass-barrel or steel-barrel fountain pen, use that to strike the window – anything that can help generate signifcant force on a small area (hatchet, knife point for hunting or pocket knife, etc).
Failing having any tools, if you can get a forearm lined up, try to strike hard with the tip of the elbow, moving from the shoulder with your body weight. Or fold your fingers at the second knuckle (tiger’s paw) and drive with that – likely to break some knuckles, but it might crack the glass. These are VERY desperate measures – far better to have the $15 lifehammer.
No, I don’t work for these guys, I just recognize a key safety tool for a good price.
And remember, the best lifesaver in a crisis is not panicking – immediately focus on the critical next step to saving yourself, don’t think about anything else, and act swiftly but deliberately. Deliberate action, a cool head, and a focus on ‘what do I do next?’ is the best odds of coming out in one piece.
November 30, 2009 at 9:31 AM