Deco time needed for diving the Titanic?
- Thread starter mangoconchile
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
A redesign of the tanks, regulator, and hoses would be needed to allow sufficient flow rates even breathing 98.5% helium which is 7x less dense than N2. At a minimum the orifices would need to be larger than standard OC equipment. Keeping %N2 to an equivalent depth of 132 ft and O2 to 1.4 atm I came up with a trimix of 0.4/98.5 for 12,000 ft. Here are the calcs:
N2: 132 ft = 4 atm. (4 + 1)atm x 0.79 ~ 4 atm. 12,000 ft = 364 atm. 4 = %N2(364+1)/100. %N2 = 1.1
O2: limit = 1.4 atm. 1.4 = %O2(365)/100. %O2 = 0.4.
Breathing heliox below 500 ft introduces HPNS or High pressure Nervous Syndrome. It manifests itself as tremors. Introducing N2 suppresses the symptoms. If 1.3% is below the minimum N2 needed to suppress symptoms then all bets are off; the dive cannot be done on OC despite overcoming the myriad of obstacles already discussed.
N2: 132 ft = 4 atm. (4 + 1)atm x 0.79 ~ 4 atm. 12,000 ft = 364 atm. 4 = %N2(364+1)/100. %N2 = 1.1
O2: limit = 1.4 atm. 1.4 = %O2(365)/100. %O2 = 0.4.
Breathing heliox below 500 ft introduces HPNS or High pressure Nervous Syndrome. It manifests itself as tremors. Introducing N2 suppresses the symptoms. If 1.3% is below the minimum N2 needed to suppress symptoms then all bets are off; the dive cannot be done on OC despite overcoming the myriad of obstacles already discussed.
EastEndDiver
Contributor
Why is this is the basic section shouldn't it be in the Advanced section?
My calculations show that no decompression time is required at all, since a gas-breathing human would be dead long before getting to the bottom. 
12,500' is an interesting problem to contemplate. Physiological limitations aside, with a bottom pressure of 5,563 PSI a full HP Scuba tank would crush before reaching the bottom. A RMV of ½ Ft³/minute would consume over 189 CFM surface equivalent. Decompression from a sat that deep would be around 120 days based on current USN tables (which bottom out at 1,600'). Gas density of HeO2 would be about 54 times greater than air at the surface.
As improbable as it currently looks, it might be possible for a diver to reach that depth IF liquid breathing were perfected.
12,500' is an interesting problem to contemplate. Physiological limitations aside, with a bottom pressure of 5,563 PSI a full HP Scuba tank would crush before reaching the bottom. A RMV of ½ Ft³/minute would consume over 189 CFM surface equivalent. Decompression from a sat that deep would be around 120 days based on current USN tables (which bottom out at 1,600'). Gas density of HeO2 would be about 54 times greater than air at the surface.
As improbable as it currently looks, it might be possible for a diver to reach that depth IF liquid breathing were perfected.
Someone wrote an article "I'm going to dive the Titanic" (or something quite close to that title) as the back cover humor article in a UK dive magazine several years ago. It was really, really funny. He was breezing thru the plans about back-mounted multisets of 18L tanks and how he would only need to switch tank sets every 8 seconds or so...
The article has a lot of neat information but was well written to be quite funny.
I'll see if I can find it.
---------- Post added November 7th, 2014 at 07:21 PM ----------
No one in the advanced section would ask this question. Not to be mean! It's just the kind of question a beginner most easily finds interesting.
The article has a lot of neat information but was well written to be quite funny.
I'll see if I can find it.
---------- Post added November 7th, 2014 at 07:21 PM ----------
No one in the advanced section would ask this question. Not to be mean! It's just the kind of question a beginner most easily finds interesting.
We explored TLV (Total Liquid Ventilation) in another thread. We still need a dilutent gas such as N2 or argon to inflate a dry suit, to pressurize a clear vision globe helmut, and to inflate a BC. There would be some small air spaces in the TLV equipment so the tanks and TLV unit would need to be made larger to withstand the pressure. The main reason for sending a "free" diver down there would be to explore inside the wreck. The equipment might be so large as to eliminate the advantage of a free TLV diver -- mobility. This suggests a maximum depth for liquid breathing in regards to exploring overhead environments.
On a run of the mill deco model becoming fully saturated takes about 3 days. The converse is also true. Your computer will continue to clock surface time for about 3 days.
R..
---------- Post added November 7th, 2014 at 07:08 PM ----------
Since this thread started it's gotten me to wondering how much pressure it would take to crush bone cells.
R..
EastEndDiver
Contributor
Similar threads
