2 Finnish divers dead, 3 injured in Plurdalen / Norway

[vincent54]

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.

Actually it isn't constructive criticism, it's criticism to make you look like you are the world's expert on diving. The facts and details are far from complete, including cause of death. I merely commented that there is rebreather equipment capable of a dive like this.

A diver familiar with his gear could change a Cis-lunar scrubber underwater. The point he would change would be in his decompression . No more complicated for a trained diver then switching to OC at max depth. Cis-lunar type rebreather or one of similar scrubber design could do the dive. Or, you could even use a Prism Topaz unit. They claim a 5 hour/40 F scrubber duration
depth/high stress. They are the units the Navy is looking at to replace their existing rebreathers. Take it up with PRISM if you don't agree with their claim. If you feel it can't be done on rebreather, so be it. Here's what it says

"The Topaz comes in at just under 45 pounds / 20 kilos fully loaded. This makes the Topaz the lightest available rebreather with its capabilities. The unit carries six pounds / 2.7 kilos of absorbent. Tested and true duration ranges from five hours with appropriate reserves in 40 degree F / 5 degrees C at high workload and all depths to twelve hours at moderate workload in 60 degree F / 16 degree C at or shallower than 70 feet / 21 meters."

 

[gianaameri]

Actually it isn't constructive criticism, it's criticism to make you look like you are the world's expert on diving. The facts and details are far from complete, including cause of death. I merely commented that there is rebreather equipment capable of a dive like this.

A diver familiar with his gear could change a Cis-lunar scrubber underwater. The point he would change would be in his decompression . No more complicated for a trained diver then switching to OC at max depth. Cis-lunar type rebreather or one of similar scrubber design could do the dive. Or, you could even use a Prism Topaz unit. They claim a 5 hour/40 F scrubber duration
depth/high stress. They are the units the Navy is looking at to replace their existing rebreathers. Take it up with PRISM if you don't agree with their claim. If you feel it can't be done on rebreather, so be it. Here's what it says

"The Topaz comes in at just under 45 pounds / 20 kilos fully loaded. This makes the Topaz the lightest available rebreather with its capabilities. The unit carries six pounds / 2.7 kilos of absorbent. Tested and true duration ranges from five hours with appropriate reserves in 40 degree F / 5 degrees C at high workload and all depths to twelve hours at moderate workload in 60 degree F / 16 degree C at or shallower than 70 feet / 21 meters."

Yep, reminds me of another "flying pigs" thread.

At any rate, let us wait for more information like exactly what make, model, year of production, and mods. rebreather these divers were actually using on this dive and then we have something further and more concrete to discuss.

---------- Post added February 12th, 2014 at 01:54 PM ----------

I am with you pertaining to rebreathers. Where I am missing your point is where do you get the info. / idea that they did not plan to go on OC at the deep protion of the dive?

https://docs.google.com/file/d/0B-iDm0Pmt3MYU3hxb0tZS3llTGpWVnZ0RWlPeDY5NTJybFVF/edit?pli=1

 

[alewar]

Or, you could even use a Prism Topaz unit.

I searched google images for "prism topaz rebreather" and kind of don't like its mouthpiece.

Anyways, is there a protocol in cave diving where the biggest guy go first in case he gets trapped in a restriction? Fortunately this cave has to exits otherwise D1 may have also died...

 

[sea_ledford]

Prism Topaz is also mostly defunct, although the new Hollis Prism 2 has the same scrubber.

Just as an FYI, when running a VERY simplified dive plan (ie openwater deco, with no cave involved) to 130 M, for a 40 minute bottom time, I get a 363min runtime (about 6 hours, so their plan was apparently a little shorter), and 149 minutes (about 3 hours) of that is at the 6m stop and shallower, so in the habitat where they may be able to come off the CCRs. And that is with a fairly conservative setting. So even with an Inspirations 3 hour scrubber, they aren't pushing scrubber times by THAT much. I agree that they are diving them well beyond the ratings though. With a fully redundant CCR, if I were in the position to do that dive (and the long list of things that entails), I would consider that aspect of it an acceptable risk.

Now if you double the bottom time to 40 minutes, you end up with the 11 hour run time, 3.5 hours of which is at 6m or less. 20 minutes dealing with a dead dive buddy in a restriction isn't that long.

It also sounds like the restriction was past the deep section, so the diver with the 11 hour run time had traverse the deep section, wait at the restriction, and then go back across the deep section. That could have been just a few minutes dealing with the restriction and another dying buddy. So over running your planned dive time by 6 hours sounds like a huge mistake, it may have been only a few minutes at depth that was unavoidable.

 

[gianaameri]

Prism Topaz is also mostly defunct, although the new Hollis Prism 2 has the same scrubber.

Just as an FYI, when running a VERY simplified dive plan (ie openwater deco, with no cave involved) to 130 M, for a 40 minute bottom time, I get a 363min runtime (about 6 hours, so their plan was apparently a little shorter), and 149 minutes (about 3 hours) of that is at the 6m stop and shallower, so in the habitat where they may be able to come off the CCRs. And that is with a fairly conservative setting. So even with an Inspirations 3 hour scrubber, they aren't pushing scrubber times by THAT much. I agree that they are diving them well beyond the ratings though. With a fully redundant CCR, if I were in the position to do that dive (and the long list of things that entails), I would consider that aspect of it an acceptable risk.

Now if you double the bottom time to 40 minutes, you end up with the 11 hour run time, 3.5 hours of which is at 6m or less. 20 minutes dealing with a dead dive buddy in a restriction isn't that long.

It also sounds like the restriction was past the deep section, so the diver with the 11 hour run time had traverse the deep section, wait at the restriction, and then go back across the deep section. That could have been just a few minutes dealing with the restriction and another dying buddy. So over running your planned dive time by 6 hours sounds like a huge mistake, it may have been only a few minutes at depth that was unavoidable.

The 3 hours quoted for that rebreather is based on the QinetiQ testing system which is NOT 40 meters at constant depth (average depth 40 meters).

The QinetiQ test is generally based on the following parameters:

Canister endurance evaluation was carried out with a CO2 injection rate of 1.6 l·min-1 whilst ventilating at a rate of 40.0 l·min-1, under the following conditions of use:
FMC apparatus
Oxygen-in-nitrogen (air) diluent gas
40 m dive profile:
• Descent rate, 20 m·min-1
• 40 minutes bottom time
• Ascent rate, 15 m·min-1
• Decompression stop at 15 m for 5 minutes
• Remain at 9 m (until carbon dioxide breakthrough of 1.0 kPa was reached)
During the canister endurance evaluation, the exhaled gas from the breathing simulator was humidified and heated to 32 ± 4 °C); breath-by-breath temperature was monitored at the mouthpiece of the apparatus.

So, basically, other than for the first 40 minutes, most of the dive is carried out at 9 meters.

Definitely not suitable as a parameter (3 hours) for a 129 meter planned dive, 4C, 5 hours.

I'd say it is an incredibly high risk to take the QinetiQ quoted 3 hours under those test conditions and go and do instead a 129 meter, 4C, 5 hours cave dive (and I am not saying what I am really thinking).

I make the average depth of the QinetiQ methodology 16 meters (if someone cares to check my math).

---------- Post added February 13th, 2014 at 02:42 AM ----------

 

[Storker]

The police are hoping to start recovering the bodies next week. They have to a large degree based their planning of the current operation on the recovery of Ståle Tveitane's body in 2006. Google Translate


The local authorities are considering a ban on diving the Plura cave. However, there's currently no law allowing for such a ban, as it will conflict with our law on right of public access (right to roam). A new law, or a modification of the one allowing for banning of base jumping in Trollveggen will be necessary. Google Translate

 

[gianaameri]

The police are hoping to start recovering the bodies next week. They have to a large degree based their planning of the current operation on the recovery of Ståle Tveitane's body in 2006. Google Translate


The local authorities are considering a ban on diving the Plura cave. However, there's currently no law allowing for such a ban, as it will conflict with our law on right of public access (right to roam). A new law, or a modification of the one allowing for banning of base jumping in Trollveggen will be necessary. Google Translate

Since you are from Norway and there may be some laws for which the authorities must release documents, any chance you can ask for a copy of the safety plan for the recovery of Ståle Tveitane body in 2006?

We could glean some interesting information from the point of view of safety as to how the authorities back then felt it was acceptable under the circumstances to carry out a body recovery dive in Plura (which is far more complex than simply traversing the system as done in this incident).

Curious as well how Rick Stanton actually did it (I must admit), what rebreather he used, and the planned dive profile.

 

[gobfish1]

"The estimated dive time was five hours, with maximum planned depth of 129 meters. A bail-out plan was communicated with the both teams, and adequate bail-out gas and bailout rebreathers were carried along."

Fact is, the plan was not as "adequate" as originally thought and 2 divers one from each time died (same place, same circumstances).

yes it says 5hr but its a two sump dive ie the 34m swim out given whats been posted ie cave lenth end to end , lenth of the deep bit , lenth of the 34m swim out lenth of sump 2 , id say if it all had gone to plan they would be back in the habitat around 180mins with 100mins o2 deco plus 45min rest them 15min swim out ,,

also the c02 thing , the divers that got jammed in at the low fisher , if hes on OTS lungs its not hard to crush the said lungs stopping him breather well , ie it would fook up the wob no end add that to some workload and well i dont need to say more ,

ps im no cave diver , but given the lenth depth and dpv id say its in the ball park , other breather diver may have just over breathed the unit having just seen his dead buddy , puts the chits up me just thinking about it .

also read other teanms have done the full run in 4hr ,

 

[gianaameri]

yes it says 5hr but its a two sump dive ie the 34m swim out given whats been posted ie cave lenth end to end , lenth of the deep bit , lenth of the 34m swim out lenth of sump 2 , id say if it all had gone to plan they would be back in the habitat around 180mins with 100mins o2 deco plus 45min rest them 15min swim out ,,

also the c02 thing , the divers that got jammed in at the low fisher , if hes on OTS lungs its not hard to crush the said lungs stopping him breather well , ie would fook up the wob no end and that to some work and well i dont need to say more ,

ps im no cave diver , but given the lenth depth and dpv id say its a good bet , other breather diver may have just over breathed the unit having just seen his dead buddy , puts the chits up me just thinking about it .

also says other teans have done the full run in 4hr ,

I do not think they used a habitat in this dive as there is no mention in their report here:

https://docs.google.com/file/d/0B-iDm0Pmt3MYU3hxb0tZS3llTGpWVnZ0RWlPeDY5NTJybFVF/edit?pli=1

I do not know the cave, but to me it seems there is no "sump" to pass for this specific dive and it is a continuous tube from water level entry point of this dive to water level exit point of this dive.

Did they instead have to walk through the Luft-Kammeret?

Notable problems to overcome are the longish deep section and one major restriction requiring kit removal at 110 meters after the deep section (...and the cold water and long deco...).

I'd understand better if someone could mark exact entry and exit points for this dive here:

 

[finnrocker]

Shouldn't that be obvious and much easier to make the rescue dive from steinugleflåget? Both bodies are in that side of the deep part and dive is mostly one steep down and up? Kind of easier than the 2006 one?