Wiu-Bimmer

That would be the trick isn't it, between your car manual, iPod, sunglasses, CDs, etc. stored in your glovebox, It would be hard to find this hammer under pressure.

Rudy

Keep in mind the obvious fact that if the car is submerged, there is a strong likelyhood that electrical systems would short out very quickly so even if the car would allow the operation of the windows, they may not work after a few seconds...

robg

I saw a story about just this subject on television one or two nights ago (cannot remember which show). The windows did continue to work for a short while the front end was submerged. The trick is to get out quickly, while the car is on or near the surface, before the pressure prevents the windows from operating properly. Myth Busters also covered this topic, focusing more on the pressure issue than on the electrical system. They tested the tools designed to break windows and they worked remarkably well. The trick to breaking a car window is to scratch or nick the surface. After that, very little force is needed.

slimb

This topic has been on my mind also...I live in Minneapolis and the recent freeway bridge collapse has again illustrated the need to be prepared in an emergency. The press coverage has included a lot of stories about what to do if you find yourself in a submerged car. The general consensus is that power windows will work even with the car submerged as long as the key remains in the ignition and not turned off (eventually the car will lose power, but the point was made that power windows not working is not the primary concern).

This does beg the question - what about BMW's and other makes that have a battery disconnection mechanism? I would assume that in most cases a scenario that involves the car ending up submerged will likely include the air-bags deploying and based on the info in the above posts, the battery would be disconnected.

It was also noted that many safety-hammer type devices designed to break car windows may not work if the car fills quickly with water (hard to swing a hammer in water), and that spring-loaded devices are better.

www.resqme.com has a device that is widely recommended.

info@trinityautosport

if this event should happen, id agree to try to open the windows asap before/as the car begins to submerge, even if that means breaking it. in addition, the sunroof. i remember my mother telling me a story of her and her cousins before in florida since they used to live there. she had her 1982 corolla and somehow went into the swamp because by the turnpike before jacksonville i think she said because of some wreckless driver. the car was submerged except for the top/roof so the sunroof was their only escape.

IrishEyes

I think I recall seeing someone using a Centre Punch to break a car window. The device barely touched the glass when it shattered.

It appears to be possible to open a door on a submerging car as long as the water level hasn't risen beyond say, 35% ot 40% or so of the total height of the car door. If it has reached the window line I reckon you'd never get the door open until the car filled and the pressure equalised.

I've also seen cars fully submerged under water and the lights were still on. I'd surmise that electric windows would still work as well. However, unless the pressure has equalised on both sides of the glass (the car has to fill with water), I don't reckon that neither the manual winding or the electric motor has the power to lower the window glass because the outside pressure is pressing the glass against the frame with too much force.

When using hammers under water (as in a submerged car), the water seemed to disspiated the potential energy in the striking movement so the required breaking force was never transferred to the glass.

Just some thoughts.

boukehj

My wife has been pressuring me to buy one of those, especially in light of all the electronics in the car (although, as all E60 drivers can confirm, they never ever fail ). In order to make sure you can reach the hammer (or indeed spring device as someone suggested), it should be mounted somewhere within arm's reach. I will get me one.

MattAu

Here is what Mythbuster concluded:

http://mythbustersresults.com/episode71