2 Finnish divers dead, 3 injured in Plurdalen / Norway

[rjk75]

Good grief! Considering the depths and time underwater, I'm surprised to read that three out of the five divers survived this.

 

[Redshift]

Oh yes, they were more than 1km in... and 11h dive time in very cold water, after having to deal with the loss of friends and other problems is just amazing.

 

[gianaameri]

Good grief! Considering the depths and time underwater, I'm surprised to read that three out of the five divers survived this.

Me too.

129 meters depth in 4C water on rebreather in a cave is a suicide plan, if I understood correctly those were the dive condition on the day and the max. planned depth.

 

[lv2dive]

So you would have done it on OC? Really, can we at least be constructive here? The fact that there were as many failures as there were, and three people made it back, points to something being done well.

129 meters depth in 4C water on rebreather in a cave is a suicide plan, if I understood correctly those were the dive condition on the day and the max. planned depth.

I believe it was on this forum that someone asked the question and I believe it bears repeating - what was the surface/in water support (if any)? Although surface/in-water support certainly would not have made a difference for the two that died.

 

[gianaameri]

So you would have done it on OC? Really, can we at least be constructive here? The fact that there were as many failures as there were, and three people made it back, points to something being done well.



I believe it was on this forum that someone asked the question and I believe it bears repeating - what was the surface/in water support (if any)? Although surface/in-water support certainly would not have made a difference for the two that died.

No rebreather scrubber that I know of can reliably and predictably operate at that planned max. depth of 129 meters at a temperature of 4C for the planned dive duration of the dive which I understand was 5 hours.

For this reason alone the dive is absolute madness (add to that all the other complexities of deep cave diving and cold water...).

I stand to be corrected if I got the rebreather scrubber durations wrong (please someone provide test data).

OC would have been safer by a large factor margin, but logistically obviously very difficult. Not a dive I would even remotely contemplate doing including OC.

 

[Vegan Shark]

This story is chilling. So much went wrong, and so tragically, that it almost seems like the plot of a horror movie.

 

[rambaldi]

No rebreather scrubber that I know of can reliably and predictably operate at that planned max. depth of 129 meters at a temperature of 4C for the planned dive duration of the dive which I understand was 5 hours.

For this reason alone the dive is absolute madness (add to that all the other complexities of deep cave diving and cold water...).

I stand to be corrected if I got the rebreather scrubber durations wrong (please someone provide test data).

OC would have been safer by a large factor margin, but logistically obviously very difficult. Not a dive I would even remotely contemplate doing including OC.

Earlier quotes seem to indicate multiple re-breathers, meaning scrubber life for the dive as planned wouldn't necessarily be an issue. As the dive happened that might not have been the case at all though.

I know guys doing caves a lot shallower than this and I believe not as far back, who each required 7 stages for a push dive last year (wasn't on the team so I may have misunderstood the exact gas logistics). You need a hell of a lot of gas when going that deep for that long, and if the restrictions were such that they got stuck then managing that many bottles would have been a mission in and of itself and would require a significant number of staging dives.

 

[vincent54]

No rebreather scrubber that I know of can reliably and predictably operate at that planned max. depth of 129 meters at a temperature of 4C for the planned dive duration of the dive which I understand was 5 hours.

For this reason alone the dive is absolute madness (add to that all the other complexities of deep cave diving and cold water...).

I stand to be corrected if I got the rebreather scrubber durations wrong (please someone provide test data).

OC would have been safer by a large factor margin, but logistically obviously very difficult. Not a dive I would even


remotely contemplate doing including OC.

There is a rebreather from years past, The Cis-lunar mk5p that can go deep and has a scrubber duration of up to 12 hours. They were used in an exploration of some south pole underwater fissures with near freezing water conditions, so the dive plan could be done on rebreather. I will look for info. but I don't think they make the unit anymore.
http://www.nwdesigns.com/rebreathers/CisLunar.htm

 

[gianaameri]

There is a rebreather from years past, The Cis-lunar mk5p that can go deep and has a scrubber duration of up to 12 hours. They were used in an exploration of some south pole underwater fissures with near freezing water conditions, so the dive plan could be done on rebreather. I will look for info. but I don't think they make the unit anymore.
Cis-Lunar Page

I am familiar with the Cis-Lunar scrubber because for all intensive purposes I use a copy.

In 20C water at shallow depths it can last and has been used to 11 hours (my copy scrubber).

6 hours in recreational dives (i.e. max depth 30 meter) 20C water, done and no problem.

4C for a little shorter than 3.5 hours at 40 meters, no problem.

In 4C waters at 129 meters for 5 hours total planned dive my personal opinion is that absent some tests actually done to verify and confirm the dependability of the scrubber under those conditions, then based on what we know about the best scrubber out there, the dive was a suicide mission.

It would be interesting to know what rebreather they were using and which scrubber exactly, and indeed if the dive was planned to be carried out on more than 1 rebreather and which.

However, let us say that they chose to use 2 rebreathers in sequence/series to obviate the limitation of the scrubber of using a single rebreather, then a single rebreather failure, that is a one failure of either one of the two rebreathers, would have compromised the safety of the divers.

Given the depth and complexity, it is unlikely the team would have had each enough gas to bail-out from a rebreather failure.

This means they would have used "Team Gas Sharing" bail-out strategy, which means if two rebreathers failed (not a low probability event in a cave at 129 meters in 4C water), then there would not have been enough gas for all to survive (as was the case).

Based on the information available, this was a suicide mission and the fact that 3 of the 5 survived is no reason to excuse and aggrandise or justify this type of diving.

 

[Storker]

I believe it was on this forum that someone asked the question and I believe it bears repeating - what was the surface/in water support (if any)?

AFAI can see, none. According to the preliminary incident report, divers 1 & 3 had to contact locals to alert the rescue service, and diver 5 was airlifted to the hospital with them:

Preparations:

The first team begins to make a hole in the ice at the Plura start site. The second team transports the exchange clothes and gears to Steinuflåget end.

The second team returns to Plura dive starting site and helps the first team to start their dive. After this, the second team starts with their own preparations and begins their dive approximately two hours after the first team.

Aftercare:

Divers 1 and 3 use a local resident to alarm the police and rescue forces.

After diver-5 surfaced, divers 1, 3 and 5 were transferred by medical helicopter and medical plane to Tromsø hospital.

https://docs.google.com/file/d/0B-iDm0Pmt3MYU3hxb0tZS3llTGpWVnZ0RWlPeDY5NTJybFVF/view?pli=1&sle=true