Ron_Jeremy

how high a fall could one survive into water?

22 posts in this topic

So I just watched the trailer for The Bridge. Pretty haunting stuff. Anyway, Wikipedia tells me the drop is 67m or 220ft. Now, I dunno that seems kinda low for death into water, don't you think? High school physics was 20+ years ago, so maybe I'm wrong...

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It's been a long time since physics class, but gravity accelerates everything at 9.8 m/s downward. So with a height of 67 meters, it will take 3.7sec to hit the water. (dist = .5 x g x t^2)

Velocity at impact would be V = g x t, so V = 9.8 x 3.7 = 36 m/s = 80 mph.

Water is pretty dense (duh, it's a liquid), so imagine hitting a concrete wall at 80mph.

Even if you didn't die on impact, you would be in cold water, with multiple broken bones (and other injuries), unconsious from the impact, and you then would drown.

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This kind of height (ie Golden Gate) falling into water is sure death. I have heard about it from other discussions about same take.

Cheers, Wizard

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I think the biggest problem isn't the impact killing you, so much as it knocking you unconscious after which one tends to drown. Getting hit in the head with your own knee is probably the big killer most of the time. Good form would go a long way.

There are cliffs near my cottage that I regularly jump off. The highest ledge is about 20 metres. At that point you start to get full-body soreness from the impact. I don't doubt that you could survive about twice that though. Anything higher and I think the odds are pretty unfavourable, so I would say that death at 220 feet is pretty reasonable and pretty likely.

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Actually, Mythbusters did an episode on high falls into water, whether there was anything you could "throw" ahead of you to break the water's surface just prior to your body hitting. I think they also did some research into GG Bridge jumpers and very few of those have ever survived the fall. I suspect Gilbo is right about people drowning after impact rather than the impact itself killing people.

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I used to do a lot of Quarry in VT. I would regularly do 65 feet (roughly 20 meters) into water. There were a number of 20-40 foot walls that you could practice flips on. The highest jump I ever did (diving) was about 85 feet. It was a pretty dumb thing to do. I'd say the line between getting hurt and dying on impact is somewhere between 90-110 feet.

Couple things to remember when doing high dives.

1: Make fists

2: Close eyes

3: Tighten abs and exhale slowly through nose

4: If you know you've screwed up mid-dive.... Do the melon (upside down cannon ball)

5: When quarry diving, first inspect the quarry to make sure there is a way out (like a rope or something). There's nothing worse than having to tread for 40 minutes while your friends drive back to town for a ladder.

Thanx Much,

Frank Russo

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I only dive off the lower ledges. I'm a little too scared to do it up higher, so I always go feet first, arms in front and tight to the body like a little knife (usually over the more tender parts in case the impact rips your legs out wide ;)).

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I used to do a lot of Quarry in VT. I would regularly do 65 feet (roughly 20 meters) into water. There were a number of 20-40 foot walls that you could practice flips on. The highest jump I ever did (diving) was about 85 feet. It was a pretty dumb thing to do. I'd say the line between getting hurt and dying on impact is somewhere between 90-110 feet.

Couple things to remember when doing high dives.

1: Make fists

2: Close eyes

3: Tighten abs and exhale slowly through nose

4: If you know you've screwed up mid-dive.... Do the melon (upside down cannon ball)

5: When quarry diving, first inspect the quarry to make sure there is a way out (like a rope or something). There's nothing worse than having to tread for 40 minutes while your friends drive back to town for a ladder.

Thanx Much,

Frank Russo

Excellent set of rules.

But I must ask... Is #5 from personal experience? :P

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5: When quarry diving, first inspect the quarry to make sure there is a way out (like a rope or something). There's nothing worse than having to tread for 40 minutes while your friends drive back to town for a ladder.

Thanx Much,

Frank Russo

Excellent set of rules.

But I must ask... Is #5 from personal experience? :P

It was one of the worst "personal experiences" of my entire life. There were only two times in my life that I thought I was going to abso-friggin-lutely drowned. That was one of them. The other was when someone "fell" into a quarry (a dog knocked her in) and skimmed the edge on the way down. Marble quarry walls have a 4 inch lip every 8 - 16 feet where the blocks were cut out, so getting away from the wall is important. Anyhoo, I dove in, and had to swim this mouth-breather to the other side for EMTs to pick her up. I get her to the other side, EMTs put her on the lift and into the wagon. At this point, I'm 5 feet from the wall (to get out of the water) and absolutely exhausted. It is at that exact moment that my body tells me that it's out of gass. I'm 5 feet away, and totally unable to swim it. I had no idea that something like that could happen. I went down, no yelling, flailing, or anything. Friends had to yank me out.

The lesson? While exhaustion sneaks up on you, human bodies have a little reserve left over to get you out of sticky bits. This reserve is definately a finite resource. There's no telling when it runs out. Your body will simply quit without warning, like a light that gets turned off.

If you're swimming, and exhausted, get the F out of the water immediately.

Last quary story... You may think it's cool to play "Al Capones Vaults" with the trunk of a submerged Buick Skyhawk. It's definately not cool. Think before you crow-bar the trunk open under 20' of water. Unfastened spare tires are not merciful at that depth.

Frank

Edited by Big Buck Hunter

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I think the biggest problem isn't the impact killing you, so much as it knocking you unconscious after which one tends to drown. Getting hit in the head with your own knee is probably the big killer most of the time. Good form would go a long way.

That, and even if you were still conscious, the broken bones, dislocated limbs, and other injuries would probably make it really difficult to swim to shore or even stay above water. Hopefully, the person would be unconscious before drowning, instead of awake while drowning.

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Some pretty interesting stuff, fellas. I guess if the water was aerated (think: screen at the end of your kitchen faucet) the chances of survival would be greatly increased.

Hopefully, the person would be unconscious before drowning, instead of awake while drowning.
I've heard that drowning is one of the most peaceful ways to go.

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Hopefully, the person would be unconscious before drowning, instead of awake while drowning.
I've heard that drowning is one of the most peaceful ways to go.

Correct, as the brain will resort back to the pre-natal experience and let the lungs fill with fluid. (Because it's one of the very first experiences that a child knows, it doesn't see anything wrong with it - eg lungs full of fluid). The lack of oxygen in the blood stream results in basically the person falling into a sleep like state, at which the brain will starve of oxygen and viola!

Anyone that's seen the movie - The Abyss, will remember late in the movie that the divers use an oxygenated liquid to breath to help cope with the pressures at extreme depth. Same principle, except normal sea or fresh water lacks the oxygen needed to sustain a human.

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Chances of survival are increased if the water is really cold (reduces oxygen requirements to allow rescuers more time).

mouse.gif

This original article from 1966 first documented the use of perfluorocarbon for breathing. It wasn't until ~25 years later that additives were developed that could successfully prevent lung damage from the perfluorocarbon and also allow it to be used as an expensive blood substitute (for Jehovah's Witnesses and others that refuse blood products, or for long-term storage in bomb shelters, etc).

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I saw Mexican divers jump off the famous cliff at Acapulco from various heights up to 60 ft high, all afternoon until it was too dark to take good photos. Each diver would be seen minutes later walking up to our platform looking for "appreciation" ( well hey it is Mexico). It was so routine for these guys, apparently any good dive below 80ft is quite survivable given training. Not that I did anything of the sort to prove this, the most I've ever braved was diving off 6ft platforms at swimming pools.

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Yeah, that was pretty interesting. I like the part 'bouts the ants :lol:

Interesting facts

Some living creatures have a terminal velocity that is not fatal. For example, ants can survive falls from heights that would be easily fatal for humans. But cliff diving ants would not be nearly as popular with tourists in Acapulco.

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There are documented jumps from as high as 250m (that one was from a zeppelin over the sea, IIRC)

People who do those are the same crop that climbs 8000m mountains without oxygen supply or do 100 pushups on one fingertip (the record for this one is 134 or so).

Meaning it has absolutly no meaning for the survivability of even a well trained normal person trying to do it.

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Sorry to wander off topic, but Chewy and bfg's comments brought it to mind: In the scene in The Abyss where they show the rat being placed into the perfluorocarbon, it's real. That was real perfluorocarbon, with a real rat. The entire sequence was real. They would have used a longer single-camera show of it, but the rat, uh, 'spoiled' the fluid, so they had to use different cuts that didn't make that obvious.

Right before the movie opened, the rat died of natural old age. The actor that was the 'keeper of the rat' said in an interview that reporters were very dubious of the rat's actual demise. "Yeah, sure he just died last week...."

The actual fluid isn't pink (like in the movie, where it was dyed pink so that it would be more visually obvious that it was 'different',) and the human actor didn't subject himself to it. (Because the fluid washes the protective mucus away from your lungs, which makes someone VERY prone to infection after having used it. For a rat, a couple days of antibiotics works, but a human takes months to fully recover.)

All of this info comes from the DVD release's 'behind the scenes' special.

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It's been a long time since physics class, but gravity accelerates everything at 9.8 m/s downward. So with a height of 67 meters, it will take 3.7sec to hit the water. (dist = .5 x g x t^2)

Velocity at impact would be V = g x t, so V = 9.8 x 3.7 = 36 m/s = 80 mph.

Water is pretty dense (duh, it's a liquid), so imagine hitting a concrete wall at 80mph.

Even if you didn't die on impact, you would be in cold water, with multiple broken bones (and other injuries), unconsious from the impact, and you then would drown.

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It was one of the worst "personal experiences" of my entire life. There were only two times in my life that I thought I was going to abso-friggin-lutely drowned. That was one of them. The other was when someone "fell" into a quarry (a dog knocked her in) and skimmed the edge on the way down. Marble quarry walls have a 4 inch lip every 8 - 16 feet where the blocks were cut out, so getting away from the wall is important. Anyhoo, I dove in, and had to swim this mouth-breather to the other side for EMTs to pick her up. I get her to the other side, EMTs put her on the lift and into the wagon. At this point, I'm 5 feet from the wall (to get out of the water) and absolutely exhausted. It is at that exact moment that my body tells me that it's out of gass. I'm 5 feet away, and totally unable to swim it. I had no idea that something like that could happen. I went down, no yelling, flailing, or anything. Friends had to yank me out.

The lesson? While exhaustion sneaks up on you, human bodies have a little reserve left over to get you out of sticky bits. This reserve is definately a finite resource. There's no telling when it runs out. Your body will simply quit without warning, like a light that gets turned off.

If you're swimming, and exhausted, get the F out of the water immediately.

Last quary story... You may think it's cool to play "Al Capones Vaults" with the trunk of a submerged Buick Skyhawk. It's definately not cool. Think before you crow-bar the trunk open under 20' of water. Unfastened spare tires are not merciful at that depth.

Frank

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OMG, I got into a debate about how high you could quarry jump before instant death and your posts had us hysterically laughing. Good info too. I wish I was your friend! Sounds exciting.

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