omitted decompression after a VERY long exposure time at 2,57 bars

[lowwall]

Hi, I’ve a question for the hyperbaric doctors of this forum which concerns omitted decompression after a VERY long exposure time under pressure.

I suppose that a person that was submitted during 14 hours to an absolute pressure of 2,57 bars and is then decompressed within less of an hour to the atmospheric pressure has very little chance to survive. But what I would like to know is how long it would take to that person to pass away. Is it a question of hours or minutes?

Thanks in advance for your reply.

With nearly an hour of deco time, this could absolutely be survivable. This is not that far from the old Haldane critical ratio of 2:1. Assuming someone could control the deco speed, take a minute up to 4-5 meters and leave it there until you have 3 minutes left and then slowly surface.

The slowest tissues would still be supersaturated, but not fatally. There should be time to get the victim to a chamber for treatment.

 

[Imla]

For more information on the Byford Dolphin accident in 1983, the report from the government can be found here: Petroleumstilsynet : NOU 1984:11 Dykkerulykken på Byford Dolphin 5 november 1983 [Rapport]
Written by the expert commision that did the inquiry of the accident.

Or link to LIbrary here: Nasjonalbiblioteket

(These work in Norway. Not sure if they work for non-citizens) And they are of course written in Norwegian.

 

[lowwall]

For more information on the Byford Dolphin accident in 1983, the report from the government can be found here: Petroleumstilsynet : NOU 1984:11 Dykkerulykken på Byford Dolphin 5 november 1983 [Rapport]
Written by the expert commision that did the inquiry of the accident.

Or link to LIbrary here: Nasjonalbiblioteket

(These work in Norway. Not sure if they work for non-citizens) And they are of course written in Norwegian.

Short version here: Byford Dolphin - Wikipedia

But this isn't about the OP's incident. Are there any details on that?

 

[OTF]

This thread needs @Akimbo insight

 

[Cthippo]

Short version here: Byford Dolphin - Wikipedia

But this isn't about the OP's incident. Are there any details on that?

This is exactly about OPs incident. Explosive decompression of a diving bell / habitat aboard a drill rig.

I think he is asking if, had the expolsive decompression not killed them, would DCS have done so?

 

[lowwall]

This is exactly about OPs incident. Explosive decompression of a diving bell / habitat aboard a drill rig.

No it's not. The original post (reflected in the thread title) asked about a "person that was submitted during 14 hours to an absolute pressure of 2,57 bars [15.7 meters of water equivalent] and is then decompressed within less of an hour".

The Buford Dolphin incident involved saturarion divers who suffered instant decompression from 9atm absolute or 80 meters of water equivalent.

 

[Papyone]

With nearly an hour of deco time, this could absolutely be survivable. This is not that far from the old Haldane critical ratio of 2:1. Assuming someone could control the deco speed, take a minute up to 4-5 meters and leave it there until you have 3 minutes left and then slowly surface.

The slowest tissues would still be supersaturated, but not fatally. There should be time to get the victim to a chamber for treatment.

The place was decompressed from 15,7 m to 0 m in less than an hour. The exact time is unknown and can as well be in less than half an hour. No stops were made during this decompression.

 

[Papyone]

This is exactly about OPs incident. Explosive decompression of a diving bell / habitat aboard a drill rig.

I think he is asking if, had the expolsive decompression not killed them, would DCS have done so?

No that's not what I'm asking.

 

[lowwall]

The place was decompressed from 15,7 m to 0 m in less than an hour. The exact time is unknown and can as well be in less than half an hour. No stops were made during this decompression.

Nothing definitive can be stated given that starting depth. It's been outside of acceptable parameters for over a century. However, prior research and reports on those working under pressure such as caisson workers and salvage divers suggests that such an ascent would normally be both survivable and not immediately incapacitating, however injurious it would be too long term health. Much depends on the details of the ascent.

https://en.m.wikipedia.org/wiki/Decompression_sickness#Timeline

 

[scubaozy]

No that's not what I'm asking.

I will repeat what I said earlier, closest data you can find about this is around caisson workers, they probably did work 4-12 hrs shifts and returned to 1ata within minutes. There are tons of articles about this in the net but you will have to do tedious work of going through them your self and try to verify sources, exact bottom times, rate of bends and rate of fatality. Certainly not everyone worked in caisson died or had serious bends, but many did.