2 Finnish divers dead, 3 injured in Plurdalen / Norway

[alewar]

Team 2 tried to go through the restriction probably because that was the shortest way out. Perhaps they also wanted to see if the other diver from team 1 was also dead on the other side...

 

[Nirvana]

The 3 survivors have given a detailed report of the incident to the diving authorities (In Finnish). Main points in brief:

- 2 teams. First team had two divers (numbered 1 and 2), Second team had three divers (3,4,5).
- Second team went in 2 hours after the first team
- The divers had gone through the bailout plan
- They used rebreathers
- They carried along extra rebreathers as well as extra open circuit gas
- The plan was to dive through the cave and meet at the other side
- Deepest point 129 meters

Early dive for team one goes ok, until diver number 2 from the first team gets stuck in a tight spot after the deepest point (at 110 meters this point). Diver 1 (who already went through said spot) tries to help, but he cannot get out. Simultaneously his rebreather starts malfunctioning. Despite trying to help in any way he can, diver 1 has to witness diver 2 perish.

Diver 1 goes up and out the other side. Intended dive length of 5 hours turns to 8, and he has to skip 45 mins of the 6 meter deco, but gets no dcs symptoms.
(during deco at 12 meters he meets diver 3 from second team)

Second team early dive goes well also until they come to the tight spot where they find diver 2 from the first team dead, still stuck and blocking further passage.

After a failed attempt to move the body out of the spot, diver 3 from second team removes gear, pushes them through the spot and manages to move through it. Simultaneously, without diver 3's knowledge, diver 4 has run into problems with his rebreather on the other side of the tight spot. Diver 4 has switched to open gas, but despite help from diver 5, he dies. Diver 3, on the other side of the tight spot, assumes that divers 4 and 5 turned back, and moves on, and eventually meets diver 1 at deco. Diver 3 has to skip 80 minutes of deco at 6 meters (also an 8 hour dive), and gets mild dcs symptoms (joint pain).

Diver 5 turns around after diver 4 dies, has more problems with his equipment and dive time becomes over 11 hours. He has to skip 90 minutes of the 6 meter deco, but has no sympotms.

---

So from the report it seems that the deaths were not strictly related. Both had rebreather malfunctions.

---------- Post added February 10th, 2014 at 06:24 PM ----------

Link to the report (In Finnish):
Sukeltajaliitto ry - Näytä uutinen

Google translated to english:
Google-kääntäjä

The second team entered the water 2 hours after the first team.

So, they would not have known about the dead diver.

What is not clear is why the second team did not immediately turn the dive upon finding a dead body instead of continuing on the traverse.

These are tough decisions to make on the spot bearing in mind that at 4C deep on rebreather in a cave meeting face to face a dead body one does not necessarily think too clearly.

However, (speculation) I suspect that Team 2 having already passed the deep section and being at 110 meters felt it was "safer" to stick to the plan.

I would have not tried to negotiate the restriction at 110 meters, but meeting a dead body at (or stuck in) the restriction I would have turned the dive immediately.

Maybe (hypothesis, not fact) for Team 2 to proceed through the restriction (and attempt an unplanned body recovery at 110 meters...) is another lesson to be learned (i.e. don't do it and turn the dive immediately) from this diving incident.

Thanks, Gian.

In an effort to be clearer, though, I've quoted the post that contains the report I was referencing. From reading it, it is not certain whether a) diver 1 met diver 3 while the former was at his deco stop and the latter was going in; b) both divers were in deco, perhaps at different depths; c) they did not in fact meet before they were both out of the water and the report is wrong.

I do not know if the exit point used by each diver was the same as the entry point, which would help ruling out one ore more of the scenarios described.

 

[gianaameri]

Thanks, Gian.

In an effort to be clearer, though, I've quoted the post that contains the report I was referencing. From reading it, it is not certain whether a) diver 1 met diver 3 while the former was at his deco stop and the latter was going in; b) both divers were in deco, perhaps at different depths; c) they did not in fact meet before they were both out of the water and the report is wrong.

I do not know if the exit point used by each diver was the same as the entry point, which would help ruling out one ore more of the scenarios described.

My understanding is that the dive was a traverse meaning you are diving a "Cave System" composed of two caves with two different entrances and the two caves being joined.

So, you enter one cave and exit a different cave - you "traverse" a "Cave System."

I think the surviving divers all met at some point having completed the traverse (so they went through the deep section at 129 meters, and the major restriction at 110 meters thereafter, and then exited from a different point where they entered).

I may be wrong, but this is what I understand.

 

[Mike.D]

The term "lunacy" was in respect of the suggestion by a poster to replace a scrubber underwater as part of planned dive to 129 meters, 4C, 5 hrs. (in a cave, under ice...).

The deep section of this cave traverse runs for "only" 400 meters.

My suggestion to future planners (and there is a body recovery or two to do) is to avoid the prior mistakes by:

1. Using a Meg ISC with 8 lbs. Radial
2. At 100 meters switch to OC, negotiate the restriction, 400 meter run on OC for the deep section
3. End of the deep section, switch back to Meg ISC with 8 lbs. Radial

A little bit of constructive criticism so that we can learn from the mistakes made on this dive ought to be appreciated by the families of the survivors.

I don't to change the subject but can someone please quickly explain why it would be safer to switch to OC during the deeper part of the dive?
I don't dive Rebreather so I'm a little stumped.
Cheers
Mike


Sent from my iPhone using Tapatalk

 

[Storker]

I do not know if the exit point used by each diver was the same as the entry point, which would help ruling out one ore more of the scenarios described.

That's in the links already posted in this thread.

The dive was a traverse from Plura to Steinuglflåget. Divers 1 and 3 were able to negotiate the restriction where diver 2 died, and surfaced at Steinuglflåget. Diver 5 turned the dive at the restriction and surfaced at the entry point at Plura.


--
Sent from my Android phone
Typos are a feature, not a bug

 

[gianaameri]

I don't to change the subject but can someone please quickly explain why it would be safer to switch to OC during the deeper part of the dive?
I don't dive Rebreather so I'm a little stumped.
Cheers
Mike
Sent from my iPhone using Tapatalk

Longish story, but with a rebreather you use your lungs as a pump to re-circulate your gas in a system made of usually two bags and a filter and two one-way valves (hoses, DSV, mouthpiece...).

This is hard work and the deeper you go the harder it gets due to increased gas density. Furthermore, due to depth, gas density, and cold water the filter removing the CO2 becomes less efficient.

The WOB ("Work-of-Breathing") of a good rebreather is multiples that of an OC regulator.

So, by switching to OC at 100 meters for the deep section you reduce WOB and reduce the risk of CO2 intoxication.

 

[Nirvana]

I don't to change the subject but can someone please quickly explain why it would be safer to switch to OC during the deeper part of the dive?
I don't dive Rebreather so I'm a little stumped.
Cheers
Mike


Sent from my iPhone using Tapatalk

I don't dive rebreathers either, but my understanding is that they present a significantly greater WOB. In addition, the scrubber itself may not be very efficient at that depth, considering the density of gas being moved through it. Therefore, OC would be safer from a CO2 retention standpoint at maximum depth.


Edit: it seems gianaameri beat me to it.

 

[KellyAsh]

This thread is moving fast.

Thank you for re-posting the text. What is confusing is that if the extra CCRs were for bailout, why did the one diver bailout to OC instead of a bailout CCR unit? I'm not a CCR diver so I don't have the full understanding of all of their options so maybe it's my ignorance of CCR diving that's confusing me.

Can someone clarify this for me or is this the result of a lack of, or confusion of, available information?

 

[gianaameri]

This thread is moving fast.

Thank you for re-posting the text. What is confusing is that if the extra CCRs were for bailout, why did the one diver bailout to OC instead of a bailout CCR unit? I'm not a CCR diver so I don't have the full understanding of all of their options so maybe it's my ignorance of CCR diving that's confusing me.

Can someone clarify this for me or is this the result of a lack of, or confusion of, available information?

OC has lower WOB and is a more reliable system.

So, it is the preferred bail-out choice.

It may be the only choice because if you are intoxicated by CO2, the only way (and this is a slim chance) to maybe exit the intoxication is by moving to a system with clean gas and lower WOB than the system you are currently using.

If you are intoxicated by CO2 especially at those depths, moving from one rebreather to another with the same WOB, won't save you.

Switching to OC which has a much lower WOB gives you a better chance to recover (slim, but much much better and the only viable alternative to recover from a rebreather CO2 hit deep).

 

[KellyAsh]

OC has lower WOB and is a more reliable system.

So, it is the preferred bail-out choice.

It may be the only choice because if you are intoxicated by CO2, the only way (and this is a slim chance) to maybe exit the intoxication is by moving to a system with clean gas and lower WOB than the system you are currently using.

If you are intoxicated by CO2 especially at those depths, moving from one rebreather to another with the same WOB, won't save you.

Switching to OC which has a much lower WOB gives you a better chance to recover (slim, but much much better and the only viable alternative to recover from a rebreather CO2 hit deep).

I see. This is a pretty surprising revelation for me considering anytime in my life dealing with life or death situations and mechanical gear, both in the military and in the civilian world, the main consideration when choosing a piece of kit for a particular mission is reliability. All other factors come in second place and below, ie extended range, portability, comfort, etc.

It seems that in the CCR world, reliability takes a back seat to the advantages of convenience of CCR while downplaying the importance of reliability. This ideology would never survive in any other life threatening activities that I've ever known, including firearms, personal defense, parachuting, rappelling, tree climbing and felling, riding bulls, and others.

Am I missing something on this or is this just the risk CCR divers accept?