electric door locks and water 3

[amorrison]

Sad, tragic story

http://edition.cnn.com/2004/US/10/25/nj.suv.drownings.ap/index.html

What are the facts about the operation of electric door locks in river water?
A friend says electric locks will not work when submerged.

 

[ivymike]

I'm guessing that the problem wasn't with the power locks not working, but with the force of the water holding the doors shut. From what I've heard, you should take a breath, lower the windows, wait for water to fill the rapidly sinking car, then open the door and swim out (or exit through the window, if you fit).

 

[MintJulep]

I've never seen a car door that didn't also have a manual unlock.

 

[TheTick]

From what I've heard, you should take a breath, lower the windows, wait for water to fill the rapidly sinking car, then open the door and swim out (or exit through the window, if you fit).

Of course, try getting the electric windows to work. Still, open vents should let water in and eventually equalize pressure. The real trick is holding your breath in 10°C (40°F) water. The gasp reflex usually makes short work of people trapped in such situations.

 

[GregLocock]

I can think of cars that have no manual lock on the rear doors, so if the child locks are locked you are in trouble.

I don't know how the lives saved in rollovers vs lives lost by drowning pans out, but keeping people inside rolling cars is essential.

Cheers

Greg Locock

 

[patprimmer]

Also, if you are conscious when the car goes into the water, you have a much better chance, and I would think in most circumstances, as least a bit of time to think about what to do.

I also imagine, that quite often, the pressure difference will be reduced to the point that a door can open, while there is still an air pocket inside, however whether that pocket is accessible to the occupants while waiting to open a door or window is another question.

I have never really experienced near freezing water, so I can't comment on it's effects.

Disorientation I am sure can be a real issue, especially at night. I know from some falls from water skis, I have found myself disoriented enough to be swimming toward the bottom until I realised the bubbles were going the other way, and I was going nowhere because of the buoyancy in the wet suit or jacket.

Re child proof locks, I am sure they are necessary in some cases, as enough discipline to avoid problems cannot be universally relied on.

The real question of more concern is do electric windows work, at least in fresh water.

Salt water I would presume would quickly dead short the battery as the car would sink engine end first, quickly flooding the engine compartment

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[MikeHalloran]

A similar incident happened here in Florida last year- ish; woman went into a canal, _did_ call 911, but no one could find her until it was too late. She couldn't describe her location to the operator. It might have had something to do with her being drunk.

My own limited experience is with small boats going down in fresh water. The electrical accessories will work for quite a while. Lights for hours; motors until the commutators get fouled by grease. The water eventually becomes conductive as the battery acid diffuses, but that takes a while. Makes a mess of switches and exposed terminations, but not right away.

Some idiot conducting a 'safe driver' course suggested not even _trying_ electric door locks or electric windows on submergence, because they'd be instantly 'shorted out' by the water. Which is just ridiculous on its face, but I didn't want to spend another hour arguing.

I can make a case for trying to get out through the windows before the car goes down or as it descends. A while ago, PBS aired an experiment conducted in Minnesota about what happens when a car goes through the ice. The experimenters had not predicted that the car would tumble, and end up on its roof in several feet of bottom mud. The diver who went down in the car nearly ran out of air before they got a cable on the car and pulled it out.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[TheBlacksmith]

As I recall, a similar argument occured among several racers in the '60's, which was solved by Phil Hill driving his rental car into the motel swimming pool. The headlights stayed on for quite a while, validating Mike's experience above. In the Navy, I have seen motors stay running in flooded compartments, so I think this is an urban myth, kept alive by "experts". If you ever saw piolts being trained in water escape, going into the water is very disorienting and most people, including me, would panic.

Blacksmith

 

[ivymike]

I have never really experienced near freezing water, so I can't comment on it's effects.

As a teen I broke through the ice on a frozen pond near my house once. I actually don't recall much discomfort. A friend went in with me, and he panicked briefly, but I was able to get his attention quickly enough and we worked together to get ourselves close to shore by breaking through the ice repeatedly. Eventually someone threw us a garden hose and pulled us out. I do remember that there was quite a bit of blood coming from my forearms after we got out, due to scratches sustained while breaking through the ice to get to shore (I guess). My arms certainly didn't hurt until we started warming up, and then it was just the "pinching" feeling of heating up when you're really cold.

 

[TheTick]

For most people, the first thing one does when immersed in freezing water is an involuntarily gasp. This often results in a lung full of freezing water, resulting in panic and more gasping.

 

[evelrod]

I noticed an article on the "Back Page" of the "Californian" (North County Times, San Diego) about a Jeep Cherokee going into a river in New Jersy yesterday. One woman had the presence to call a friend on her cell phone but not the ability to open a door or window. Witness ran along side (?) banging on the roof and windows with a flashlight---all died.

There is no explanation for panic, IMO---To those of us who have never had a personal situation resulting in total panic it is difficult to understand. I helped pull a race car driver from a burning race car and I can attest to the pure panic and total immobility of that 50+ year old driver! I had to reach in and undo his safety harness because he was "frozen". I still see his eyes looking at me.

Rod

 

[onyx01]

I both SCUBA dive and am on-call for underwater emergencies with the county rescue. In the last three years we have had two similar incidents, both were negligent drivers. Working in the automotive industry we try to protect circuitry like electric door locks, and window motors from shorting in most "wet" environments.

Now, having said this, yes the electronic devices can fail, but it is more the fact that the driver and/or passengers in the vehicle exhaust all energy trying to unsuccessfully open the doors or break the window glass. The water pressure must be equalized for this to easily happen, at which time the occupants panic and fail in their attempts.

Sad as it may be, more people are killed by someone eating fast food than talking on a cell phone and submerged under water. Yet we all hear about what the government is going to do about cell phone use and driving.

O.K off my high horse, but you get the point.

BJ


Brandon Jacobsen
Product Design Engineer - Catia

 

[JDana]

I drove a somewhat rusty Baja Bug at a good speed right off a beach into 7ft deep water once. (There was an island about 15 feet from shore, how could it possibly be that deep?)Anyway, as we initially drove in, the water came over the hood and up the windsheild. Then we popped up to where most of the vehicle was above water. Then as the rust holes allowed water to enter we slowly sank until the rear bumper hit bottom. This took a good 5 minutes in a rusty car. When we attempted to open the door, we succeeded but quickly reconsidered as it greatly increased the speed of sinking.

Gasping from cold water is less likely to occur if the water level raises somewhat slowly compared to diving in head first. I think most deaths by sinking in a car are a result of unconciousness or panic.

 

[TheTick]

One of my pet peeves is people who don't wear seat belts because they want to be able to get out of a burning or sinking wreck that much quicker. Just try getting out with your brain pasted to the windshield.

 

[Tmoose]

I'm not sure I understand how locked doors stay shut any better than unlocked doors. I would think it might initially have more to do with the strength and design of the door latch.
For sure my faithful-but-terribly-rusted Peugot's doors popped open on big bumps, locked or not.

In the 80s Volvo was advocating driving their cars with un-locked doors to help emergency extication efforts. Made sense when I read it. So when riding in a car with the auto lock feature I UNLOCK mine them after exceeding 7 mph.

 

[Timelord]

Tmoose,

Mercedes Benz must also advocate leaving the doors unlocked. My wife's 400E locks and unlocks the doors when the key is used in the drivers door. While there are manual buttons at the rear of each door, there is no button in convenient reach of the driver or passenger to lock the doors. This forces you to drive with the doors unlocked unless you reach over your shoulder to lock the doors and of course to unlock them when you want to get out. I always figured this was done to force you to leave the doors unlocked while driving.

Timelord

 

[evelrod]

All I have to say about "leaving the doors unlocked"---

I now live in a rural area but I still lock the doors when driving---you must try driving through South Central Los Angeles, Willowbrook , Compton or Gardena California at 2 AM to understand how we arrived at the habit!
We lived in Hawthorn for a while in the 60's and most of the people there were hard working, friendly people but, it only takes a couple of rotton apples...!

Rod

 

[IRstuff]

In fact, I was, and still am, annoyed at Honda for making the CRV without automatic door locks. They did it for the Pilot, but not the CRV.

TTFN

 

[Higgler]

60 minutes had an excellent segment on driving your car into water. They didn't talk about automatic windows opening. Here's the salient points that I can remember:

1) Panic is so great, most people drown cuz they forget their seatbelts are on and can't get out when they try. I realize this may sound ridiculous, but if you're panicking, who knows.
2) The best advice by far; carry a new and sharp spring loaded hole punch/hole starter. Pressing this against a side window shatters it fully and you can escape. Maybe wait till the car is almost full of water though. I keep one in our van in the ash tray (so I know where it is). You only need to use it once to make it all worth it.
3) Then there's the obvious about waiting till the waters fills up in the car, then opening the door and swimming out, etc. etc.

 

[zeusfaber]

This thread kindles a few memories

Not all the things we were taught in helicopter ditching training are relevant to this - but some of them probably are.

So far as I can remember (and it was a while back now), the key elements were:

Try to jettison the escape hatches before you go into the water - It's easier than doing it later (probably less relevant in this scenario)

Before impact, point one hand towards the exit, and cling on with it to the nearest bit of structure (Rolling around in the blind and dark, it's hard to believe that the cabin is rolling with you, and easy to believe that "out" is now the other way). Cling onto the harness release with the other hand.

Wait until all the major motion has stopped - stay strapped in and clinging on.

When the water has almost reached your face, take a breath, then put your face into the water on purpose - this overcomes the gasp reflex.

Once the water has stopped coming in, undo the harness, pull all the straps clear of you, then follow your other hand to the exit.

I've done it a few times in practice - never (thank you!) for real. Oddly, it always seemed easier in the dark.

A.