What would happen if ? ? ? Car horn under water.

shortbus

Joined Sep 30, 2009
7,766
They make emergency tools for cutting the seatbelt and for smashing the window. That, too, has been recommended to be in your arsenal of emergency tools, should you ever find yourself in the drink.
And a roll of toilet paper, in the 'arsenal', to wipe yourself after going off the bridge.
 

narkeleptk

Joined Mar 11, 2019
465
That should have done it. The older diesels used a mechanical injection system run off of the cam shaft or crankshaft, newer stuff uses EFI, except Dodge, think it's still mechanical.
It was about 10 minutes after he cut "a" fuel line that we blocked the intake. It was in the engine bay and only one line he cut.

The car was a 87 or 89 Mercedes 190D turbo.
 

SamR

Joined Mar 19, 2019
2,259
I can't put numbers on the physics but my recollection from diving years ago tells me water dampens low Freq. Our way of getting someone's attention was to tap on the tank with a metal object and it would generate a noticeable Ping for quite a distance before being damped out. Even high pitch outboards came through at a much lower Freq.
 

Reloadron

Joined Jan 15, 2015
5,509
Electric motors you mean probably?. I have only been considering if a car is submerged. As far as auto's go maybe diesels could run briefly while submerged under water but no way a gas engine will. They need 3 things, Spark, Fuel and AIR. Good luck getting any of those when submerged with out heavy modification. I imagine they stall pretty much immediately when they go under from air being cut off..
Gasoline engines designed to run under water do just fine. My father drove a jeep off a landing craft on Guadacanal and trucks I drove in the Marine Corps had a fording lever which made sure the crankcase was pressurized and crankcase pressure routed making things water tight or preventing water from coming in. All of the ignition wires were sealed and there was an air pipe extending up beside the cab. So the matter of gas, ignition spark and air isn't a problem. Granted the engine is designed for it but such engines are not unusual especially on military trucks. The new Humvee (well after my time) can have a deep water fording kit installed allowing operation in 6 feet of water. So while not common there are plenty of gasoline powered vehicles which run fine submerged. They were around during the 1940s and are still around.

Ron
 

narkeleptk

Joined Mar 11, 2019
465
@Reloadron
yes, there are many wranglers with modifications done as well to go snorkeling, its why I said with out heavy modification. I was just referring to your everyday sedans and pickup trucks.
 

shortbus

Joined Sep 30, 2009
7,766
It was about 10 minutes after he cut "a" fuel line that we blocked the intake.
Probably the return line to the tank, not the supply.

we blocked the intake.
Some old diesels used that idea, blocking the intake, to get an engine up to speed when starting. No air in means no real compression. Then when the engine is turning over good, they open the intake, and the engine fires.
 

Reloadron

Joined Jan 15, 2015
5,509
I was just referring to your everyday sedans and pickup trucks.
I give it a few short seconds, not long seconds but the short ones. :)

Ron

On a side note totally unrelated to much of anything during my career I worked with the MK46 and MK48 torpedo programs. Both used a rotary engine which burned Otto fuel II which was pretty cool stuff. Well not so cool as when engine testing the exhaust when the stuff burns is Hydrogen Cyanide. But there was no requirement for any oxidant.
 

SamR

Joined Mar 19, 2019
2,259
Junkyard car horn cheap. some scrap wire. plastic bucket full of water. unplug the wires from your car horn. extend wire to the scrap horn. drop it in bucket of water and honk away. report back with the results. enquiring minds wanna know...
 

SamR

Joined Mar 19, 2019
2,259
Back during WWII along the SE US coast the German U-Boats were sinking ships and an active coast-watch by civilians was organized. At night the subs would surface to run their diesel generators and recharge the batteries. I've been told that by putting your head underwater the engines could be detected to alert the Navy that a boat was active in that area. FWIW if true.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
4,726
At night the subs would surface to run their diesel generators and recharge the batteries. I've been told that by putting your head underwater the engines could be detected to alert the Navy that a boat was active in that area.
Passive sonar. Yes, if close enough you can hear the motor. However, the ocean is a very noisy place. It's doubtful you could hear a sub a few miles off the beach. Sensitive sonar equipment can discriminate and detect such diesel engines, and even determine the class of ocean going vessels. But the human ear would be lucky to hear a boat out five miles or more. And I would think that even a mile away is a dubious chance of hearing it.
We're amusing ourselves until you can get home a(nd) do the test.
Well you'd better amuse yourself for a while. It could be a few months before this assignment is over.
 

Berzerker

Joined Jul 29, 2018
621
Isn't this the same as "If a tree fell in the forest" thing :confused:
(one) there would have to be someone outside the water to hear it "if you could"
(two) why are you blowing a horn instead of saving your ass
(three) Now you've ruined two cars
(four) now your pool is full of fuel and unusable
(five) repairs to both cars
(six) pool repair and cleaning
Do I need to keep going?
Dreams don't always make since
Brzrkr
 

djsfantasi

Joined Apr 11, 2010
6,521
@narkeleptk the pressure agains the door makes it nearly impossible to open. However, rolling the window down may take a little effort but an electric window "should" be able to be rolled down after being submerged. From things I've seen on TV about being in a sinking car, some say to roll the window down as soon as possible, others say to wait till the car is nearly completely flooded and you are able to take one last gasp of air before rolling it down. IMO if you roll the window down while sinking the rushing water could make it difficult to gasp at that last breath of air. Plus, the inrushing water would make it impossible to get out. You'd have to sit there and wait for the cabin to fill with water. Of course, opening the window after the car is nearly completely full will make opening the window much easier and getting out much quicker due to less water rushing in.

They make emergency tools for cutting the seatbelt and for smashing the window. That, too, has been recommended to be in your arsenal of emergency tools, should you ever find yourself in the drink.
As a matter of fact, if your car has headrests, did you know their supports are pointed so that they can be used to smash a window in the event the car is submerged?

Windows my necessity are difficult to break (for safety), but if they are struck with a focused force, such as a pointed steel rod (a screwdriver can work, too), then they will shatter.

This is a useful piece of information and please help spread it.
 

shortbus

Joined Sep 30, 2009
7,766
As a matter of fact, if your car has headrests, did you know their supports are pointed so that they can be used to smash a window in the event the car is submerged?
They could be used for that but.. That isn't the reason they are pointed, it is so they go into the seat back easily on the assembly line. And many GM cars you can't remove the head rest after they are assembled. Had, 04 Grand Prix, 03 Impala, and many S-10s that you couldn't take them off.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
4,726
As a matter of fact, if your car has headrests, did you know their supports are pointed so that they can be used to smash a window in the event the car is submerged?
Never thought of that. I'll have to examine just how pointed they are. If you had asked me why they were tapered at the end I would have said it was to facilitate inserting the head rest into the seat back.
 
Top