B Simulate an altitude at 16000-18000 feet with water depth

[Rev. Cheeseman]

TL;DR Summary

Is that possible?

Hi.

If we wanna train inside a water pool like just play fighting, how much depth that we need to simulate an altitude at 16000-18000 feet? Thank you.

 

[A.T.]

If we wanna train inside a water pool like just play fighting, how much depth that we need to simulate an altitude at 16000-18000 feet? Thank you.

What do you mean by "simulate an altitude"? What physical aspect are you trying to emulate here?

 

[Rev. Cheeseman]

What do you mean by "simulate an altitude"? What physical aspect are you trying to emulate here?

Like training in a low air pressure to improve endurance and stamina.

 

[A.T.]

Like training in a low air pressure to improve endurance and stamina.

You want simulate lower air pressure under water?

 

[Rev. Cheeseman]

You want simulate lower air pressure under water?

Sorry if I was wrong but is that correct?

 

[A.T.]

Sorry if I was wrong but is that correct?

I don't even understand what your idea here is. It's either genius or not even wrong.

 

[phinds]

I assume you mean you want a water tank that would provide (1) neutral buoyancy and (2) the same resistance to motion as low air pressure at 16,000 to 18,000 feet altitude.

If that is indeed what you are looking for, then the concept is clear and the physics is nonsensical.

 

[Lnewqban]

Like training in a low air pressure to improve endurance and stamina.

Please, see:
https://wildsafe.org/resources/ask-the-experts/altitude-safety-101/oxygen-levels/

The only thing water can do for the training person is to increase the resistance to the movements.
Unless the heads are kept above the surface, you would need to solve the problem of increasing oxygen deprivation due to breath holding during around one minute of training.

That would be very different from training while having a constant level of oxygen, as it happens at high altitudes.

 

[Rev. Cheeseman]

I don't even understand what your idea here is. It's either genius or not even wrong.

I assume you mean you want a water tank that would provide (1) neutral buoyancy and (2) the same resistance to motion as low air pressure at 16,000 to 18,000 feet altitude.

If that is indeed what you are looking for, then the concept is clear and the physics is nonsensical.

Sorry forgot to tell, it is with a hose that extend above the water so one can breathe.

 

[Rev. Cheeseman]

Please, see:
https://wildsafe.org/resources/ask-the-experts/altitude-safety-101/oxygen-levels/

The only thing water can do for the training person is to increase the resistance to the movements.
Unless the heads are kept above the surface, you would need to solve the problem of increasing oxygen deprivation due to breath holding during around one minute of training.

That would be very different from training while having a constant level of oxygen, as it happens at high altitudes.

So, training underwater is more difficult than training from 16000-18000 feet altitude or a simulated 16000-18000 feet altitude inside an altitude chamber. What if we use a hose that extend above the water so he can breathe? Imagine if the water is around 6 feet deep and the person is around 6 feet and 1 inches.

 

[berkeman]

What if we use a hose that extend above the water so he can breathe? Imagine if the water is around 6 feet deep.

Do you have a local pool where you can try this? When I tried it as a kid, I only made it about 1/2 meter under water trying to breathe from a garden hose.

There is a reason that scuba divers use compressed air to breathe underwater...

 

[phinds]

Sorry forgot to tell, it is with a hose that extend above the water so one can breathe.

Which has nothing to do with the fundamental problem of your scenario. You don't seem to understand the difference between moving in water and moving in air.

 

[Rev. Cheeseman]

In a nutshell, the 16000-18000 feet altitude or at least a simulated altitude of similar level in an altitude chamber is much preferred than the other alternative which is training underwater even with a breathing hose. Thank you so much for the responses and sorry for asking the question.

 

[A.T.]

In a nutshell, the 16000-18000 feet altitude or at least a simulated altitude of similar level in an altitude chamber is much preferred than the other alternative which is training underwater even with a breathing hose.

Training underwater is not "the other alternative" which is merely less preferable. Training underwater makes zero sense to simulate high altitude. Unless you want to simulate the oxygen deprivation, and can live with the risk of drowning some people.

 

[berkeman]

Thank you so much for the responses and sorry for asking the question.

It's okay to ask questions; that's how we learn. As long as you have tried to do some reading to answer your questions first, and listen to what we reply with, all is good.

In a nutshell, the 16000-18000 feet altitude or at least a simulated altitude of similar level in an altitude chamber is much preferred than the other alternative which is training underwater even with a breathing hose.

Unless you're training to be an astronaut...

 

[Dale]

So, training underwater is more difficult than training from 16000-18000 feet altitude or a simulated 16000-18000 feet altitude inside an altitude chamber. What if we use a hose that extend above the water so he can breathe? Imagine if the water is around 6 feet deep and the person is around 6 feet and 1 inches.

The muscles that expand your ribcage are not strong enough for that. Typically once the chest is submerged more than about 2 feet deep you can no longer draw in breath. That is why the air from a scuba tank must be pressurized to the ambient pressure.

 

[Baluncore]

Sorry forgot to tell, it is with a hose that extend above the water so one can breathe.

That is a very dangerous experiment, because your lungs will fill with fluid due to the differential pressure.

 

[DaveC426913]

So, training underwater is more difficult than training from 16000-18000 feet altitude or a simulated 16000-18000 feet altitude inside an altitude chamber. What if we use a hose that extend above the water so he can breathe? Imagine if the water is around 6 feet deep and the person is around 6 feet and 1 inches.

You can't breathe through a hose at six feet underwater. Your lungs do not have the strength to draw air down against the pressure on your chest cavity.

There's a very good reason why snorkels are at most 18 inches long.

Try this with a snorkel next time you're at the pool:
Swim horizontally near the surface. Now, reorient yourself vertically, which puts your lungs a foot or two lower in the water. It will be noticeably (though not impossibly) harder to breathe.

Putting your lungs much further, let alone six feet lower, will make it virtually impossible to get a breath. It will feel like trying to suck a golf ball through your hose - to mention the fact that - unless you use a sufficiently rigid hose, it will simply collapse, cutting off your air.

 

[Baluncore]

There is another problem with breathing through a 6-foot-long hose. The volume of air per breath, is less than the volume of the hose, so you would get little air exchange.

Good ventilation would require a two valve system. You could draw in air through the hose and one valve, then vent from a valve at the side of your face mask. It would be difficult to clear water from the induction hose. The water-depth limitation remains.

 

[berkeman]

That is a very dangerous experiment, because your lungs will fill with fluid due to the differential pressure.

I dunno, I survived my experiment. But I ate at least a handful of dirt per day, and drank my water from that same garden hose.

There is another problem with breathing through a 6-foot-long hose. The volume of air per breath, is less than the volume of the hose, so you would get little air exchange.

Yeah, but when you can't draw in a breath at all, that doesn't really matter.

 

[DaveC426913]

There is another problem with breathing through a 6-foot-long hose. The volume of air per breath, is less than the volume of the hose, so you would get little air exchange.

Right! People have died because of this mistake. They don't even know they are breathing their own CO2, and they just fall unconscious.

The volume of an average breath is about 0.5l, which is 30in³.
The volume of a 6 foot long one inch diameter pipe is 56in³ - almost twice as much.

That means you are not breathing fresh air - not by half - you are rebreathing your own exhalations over and over. That's a formula for death.

 

[boneh3ad]

In a nutshell, the 16000-18000 feet altitude or at least a simulated altitude of similar level in an altitude chamber is much preferred than the other alternative which is training underwater even with a breathing hose. Thank you so much for the responses and sorry for asking the question.

Training underwater isn't even an alternative. I don't think any of us understand the logic.

Increasing altitude decreased atmospheric pressure and oxygen availability. Air is also thin and provides less resistance to movement.

Going underwater dramatically increases the pressure around you and increases the resistance to your movement (though that's roughly constant with depth).

Training underwater is literally the opposite of training at altitude.

Roughly every 10 m (33 ft) you go underwater, you add another entire atmosphere worth of pressure on your body (or anything else at that depth).

 

[erobz]

Is there any merit to experiencing similar physiological effects between the pool (high resistance) and altitude training in low oxygen environment? I think that is what is being asked or attempting to be asked.

 

[DaveC426913]

Training underwater isn't even an alternative. I don't think any of us understand the logic.

Presumably, the OP wants the strengthen the chest muscles that operate the lungs, with the hope that his will facilitate better breathing at high altitudes.

I don't know, is breathing at high altitudes anything like breathing under water pressure? Do stronger chest muscles help you at high altitudes?

 

[russ_watters]

Is there any merit to experiencing similar physiological effects between the pool (high resistance) and altitude training in low oxygen environment? I think that is what is being asked or attempting to be asked.

I don't see how they could be considered similar.

Presumably, the OP wants the strengthen the chest muscles that operate the lungs, with the hope that his will facilitate better breathing at high altitudes.

I don't know, is breathing at high altitudes anything like breathing under water pressure? Do stronger chest muscles help you at high altitudes?

Just googling a bit, it looks to me that the benefits are all in how it affects blood biochemistry. I don't see strength as being a factor.

 

[sophiecentaur]

IF you want to simulate an environment at 18000 feet you need an ambient pressure of 0.5 Bar (Half the pressure at sea level). Spending a lot of time at half normal atmospheric pressure causes the body to produce extra red blood cells. This technique has been tried by many athletes who perform better with heightened levels of red cells. An alternative way to achieve this has been tried by having transfusions of 'supercharged' blood.

For this, you need a large chamber, partially evacuated but, of course, the air in the chamber needs to be changed regularly to eliminate a build up of CO2..

Alternatively you can just breathe air with reduced partial pressure of O2. I am not recommending this but I found a website with someone's version of the technique. Possible dangers are also discussed in this link.

 

[snorkack]

One logical idea would be have a pool of "negative depth".
As in, you want an extended volume of air at pressure appreciably below ambient air? Uh, the problem is that you need to protect the evacuated volume against outside air getting in. Which means that the walls of your air volume need to have 1) airtightness to prevent the external air leaking in and 2) overall mechanical strength to prevent the external air from crushing the whole wall.

This is not impractical with reasonable technology but it is hard to do at small scale. For example, the hull of a ship with draught of 5 m will have to endure pressure of 0,5 bar water trying to either leak in or crush the hull.

Then how do you get from external air into the internal air? You might have mechanical airlocks with doors. Or else you might have a water lock - entry and exit by diving beneath the external pressure level. The principle of a diving bell - and as per Archimedes´ laws, diving bell also works when the water level inside is above the water level outside. You just have to 1) keep the edge of the diving bell below the external water level including wave bottoms and 2) keep the pressure inside the bell above water vapour pressure. And of course you also need to keep the pressure inside the bell sufficient for people to breathe in. And provide adequate volume inside to do whatever you want to do...

I suspect purely mechanic vacuum chamber with mechanical air locks would be easier. Or just travelling to high altitude.

 

[sophiecentaur]

I suspect purely mechanic vacuum chamber with mechanical air locks would be easier.

Why not take a strong* container and put your subject inside it. Then pump out enough air to equate to 0.5Bar. The air lock would only be for convenience. -0.5Bar can be easily handled by a healthy person. (As in other diving exercises, they would need to breathe in and out steadily to avoid stressing the alveoli whilst the pressure changes. Also, be prepared for bleeding noses and ears if you change the pressure too fast.

* Much stronger than an ordinary oil tanker tank.

 

[snorkack]

Why not take a strong* container and put your subject inside it. Then pump out enough air to equate to 0.5Bar.

* Much stronger than an ordinary oil tanker tank.

As demonstrated, the strength for resisting 5 m water pressure is the design requirement for a hull to draw 5 m.
In case of a wet bell operating at rarefaction, you would have obvious alternatives:
pump out air from the inside;
equalize air pressures, then lift the bell relative to outside water level;
equalize air pressures, then hold the bell in place while water level falls outside.

 

[sophiecentaur]

As demonstrated, the strength for resisting 5 m water pressure is the design requirement for a hull to draw 5 m

You are right. But a regular oil drum will collapse with a moderate reduced pressure. It's one of those demos 'everyone' does.

Googled "thickness of a ship's hull" and I got several opinions - starting with 15mm. And ships need to have many extra forces acting on them. Many oil drums are not many mm thick. But I was just erring on the safe side!