chatGPT Bühlmann ZHL-16C graph

[harvalen]

Sorry, I don't quite understand what you mean with the O2.

The dive profile you provided has a US navy profile embedded in it with both Air and Oxygen (O2) decompression. I assume it's from this incident: Four who died were not trained for Delta P - Trinidad and Tobago

Not sure what that US navy profile is supposed to represent, the "exceptional exposure time" doesn't match the diver that survived or the 4 that died. Maybe there was a theoretical rescue scenario at that point? I don't remember all the details from the incident.

 

[David Carron]

Great, this is effectively quite different than the AI graph.

Would it be possible on your graph to extend the time to see when the N² tension of the different compartments are again at 0.79

There you go. 64 hours of data. Still doesn't correspond to the Carribean delta P incident though.

 

[Papyone]

There you go. 64 hours of data. Still doesn't correspond to the Carribean delta P incident though.

View attachment 912279

Thanks again.
Unfortunately, I don't have much experience with this type of decompression model, but from what I can see on the graph, it seems that the long compartments took quite a while to return to normal tension. And I also assume that the divers' decompression must have been well above the M-Value for such a dry dive.
Yes this profile is indeed the one the five, then 4 divers were submitted during the Paria incident.

 

[David Carron]

Thanks again.
Unfortunately, I don't have much experience with this type of decompression model, but from what I can see on the graph, it seems that the long compartments took quite a while to return to normal tension. And I also assume that the divers' decompression must have been well above the M-Value for such a dry dive.
Yes this profile is indeed the one the five, then 4 divers were submitted during the Paria incident.

The difference between this simulated profile and the real one is that it assumes that the workers were saturated at surface pressure at the moment of the incident whereas in reality they had been working for some time in the habitat pressurised to around 4m.

The highest calculated GF was around 200%, unsurprisingly at the workers' return to surface pressure where ZHL16 predicts around five hours of decompression stops (although you might like to note that there's no real reason think that ZHL16's predictions are applicable here)

A slightly more realistic chart might look like this.

 

[Papyone]

The difference between this simulated profile and the real one is that it assumes that the workers were saturated at surface pressure at the moment of the incident whereas in reality they had been working for some time in the habitat pressurised to around 4m.

The highest calculated GF was around 200%, unsurprisingly at the workers' return to surface pressure where ZHL16 predicts around five hours of decompression stops (although you might like to note that there's no real reason think that ZHL16's predictions are applicable here)

A slightly more realistic chart might look like this.
View attachment 912352

Yes you’re right, four of the divers were already working in the habitat since about 35 minutes when the accident did happen. But I suppose that this doesn’t change the final result of the graph.

 

[Papyone]

The dive profile you provided has a US navy profile embedded in it with both Air and Oxygen (O2) decompression. I assume it's from this incident: Four who died were not trained for Delta P - Trinidad and Tobago

Not sure what that US navy profile is supposed to represent, the "exceptional exposure time" doesn't match the diver that survived or the 4 that died. Maybe there was a theoretical rescue scenario at that point? I don't remember all the details from the incident.

The blue line (and black) is indeed the profile of the 55 feet decompression table the divers had to follow if a rescue had been attempted. This profile shows that at 20h45 they would have come at the end of the table and from then on it would have been very difficult to decompress them safely.