This is essentially a small diving bell that fits over the user's head and allows him to descend to moderate depths. It does not protect the user from pressure, but could be easily modified to do so. It should be noted that I am not responsible for any injuries sustained while using this device; If, however, you take the proper precautions, the possibility of this is small, even in the event of a pressure failure. This helmet can be made from simple, inexpensive materials. It can be operated by two people, and with some design modifications, could be made self - contained. I have made sustained dives of over two minutes without a problem, at depths of approximately ten feet.
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This apparatus consists of a watertight helmet which partially encloses the diver's head, and is connected to a topside air supply by a hose. It is chained or otherwise affixed to a ballast weight to counter the positive buoyancy of the air trapped inside the helmet. It is very similar to diving apparatus used in the early days of ocean exploration.
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dangerous and result to lung over-expansion (that's death) even in a
deep pool or poisoning from contaminated air, depending on how it is
constructed.
If you like to explore the depths, try freediving or scuba diving and do
not try this, please.
I apologize for posting this to somebody's instructable, I know that they
probably spent a lot of time and effort on making it, but this can be fatal
in the wrong hands.
At 10 ft depth, the air is 5psi. When you return to the surface, that air wants to expand.
I don't think you need to worry about the bends at 10 ft. I'm not sure what depth the bends can occur.
It is like snorkeling but the snorkel is attached to a hose which goes to the air supply, which floats on the water's surface.
I think if one only goes the depth of a swimming pool, just an air hose to the surface would be just fine. No?
Beyond that, however, your diaphragm can't draw air against water pressure, deeper than four or five feet; further down, you'll find yourself exhaling and unable to inhale (which, by the way, greatly reduces your buoyancy; you may have to actively swim to return to the surface, which rapidly gets more difficult when you're already out of breath).
The floating air pump systems work fairly well -- but some important safety features shouldn't be neglected. First, if you use a gasoline engine, you need to insure that your breathing air intake doesn't draw your engine exhaust (gasoline fumes will make you feel ill, but carbon monoxide can kill you). Second, you'll need a regulator of some sort at your mouthpiece, else the airflow and pressure from the air pump can rupture your lungs and potentially kill you. Third, the hose must be less than thirty feet long, to ensure you can't go deep enough to need to decompress. Finally, you need to have enough training in SCUBA diving to know things like the reason you need to exhale continuously as you ascend, else you can *still* kill yourself with one of these...
Hypercapnia - excess breathing of carbon dioxide that commonly gets caught in "dead space" of helmet. Note the difference in the Mark V dive helmet and KM-37. Over time, engineers reduce the dead space to reduce this danger. I suggest designing a lower profile helmet.
Asphyxia - simply put, lack of air to breath (in case compressor shuts off or leak in hose or what not)
Carbon monoxide poisoning - By using a regular compressor and not a diver's are compressor, which specifically uses lubricants and has an intake far far from the exhaust, you increase your probability of death. Consider it like breathing air from the exhaust of a car...not good. I suggest researching proper lubricants and different diver air compressors. Also, learn more about High pressure vs Low pressure compressors.
Decompression sickness - using the compressor will allow you to have more "bottom time." depending on depth and bottom time you may need to decompress, this allows nitrogen gases to be removed from your body. If you surface without decompression you may find yourself immobile. This is because a nitrogen bubble is trapped in the nerves that allow you to operate your legs, arms, or whatever it is that can't move. You then need to find a recompression chamber to shrink the bubble immediately. When treated hopefully the immobile body part will be able to move (expect loss of sensation). Aside from that, you can also die from Decompression sickness, depending if the bubble is trapped in your head or heart.
Pulmonary Over Inflation Syndrome - Air can get trapped between the lungs and chest cavity. This is more painful than anything else, see a doctor. If you do not regulate the air from the compressor with respect to minimum manifold pressure you may also over inflate your lungs. Think of the cartoon breathing in a balloon and over inflating. This also happens when you go from a deeper depth to a shallower depth with too much air already in your lungs.
Arterial Gas Embolism - Those going up and down 20 ft of water may find themselves within the cold grasp of AGE. Though different from Decompression Sickness it is treated the same as has many of the same dangers.
I made this list as short as possible. If you research each danger you will find greater detail. I encourage everyone to take a class in diving to learn how ti mitigate the dangers. I wish you all safe diving and good luck.
I google'd home made diving bell and found this.
I signed up just to confirm xTOGx and warn people that this is dangerous and not smart.
You CANNOT simply use a regular air compressor to pump breathable air. You will get sick and possibly die. If you survive you will most likely never dive again. You will become too sick with respiratory issues, or you will become too scared to dive from a scary experience.
If you want to experience this the RIGHT way, the way that is WORTH IT, then look up Kirby Morgan Helmets. Kirby Morgan makes industrial grade SSAir Diving Helmets. An even cheaper more recreational way are Bandmask surface supplied air masks.
Developing surface supplied diving helmets for military and industry use took decade of research and many many lives of divers. Even if you dont kill yourself, you can mess yourself up for life and prevent yourself from ever being able to dive again!
Sincerely,
A guy who is certified to 1,000 foot depths.
-Bear
His mistake was that he held his breathe while surfacing. 3-5 feet and one breathe may be enought to seriously damage your lungs and die.
ballast (lbs)=(capacity in gallons of inner helmet * 8) + (-weight of helmet+5lbs)
WHEN RETURNING TO THE SURFACE YOU MUST EXHALE!!!
and im making more upgrades: my mask is about to get an auto pump made of an airco fan (the inflator of airthingis blew up) and the lights work underwater and our newest idear is an vacumcleaner for underwater to suck up stuff thats buried under sediment :) like my watch :(
With ALL of these devices it is imperitive to adhere to these safety rules:
Never use alone but under ACTIVE supervision.
Never use any kind of compressor that uses oil AT ALL. This leads to suffication by coating the lungs preventing respiration. You cannot be saved once the lungs are coated.
Stop immeadiately if your vision becomes cloudy. I have played with this type of activity during my preteens and luckily survived.