Report from Fatality at Devil’s Ear

Drmike

I pressume its ok to reprint this nsscds post here - in the interest of safety.



Posted: Mon May 12, 2008 3:37 pm Post subject: Fatality at Devils Ear UWS Vol 35 #3




Reprinted by permission from Lamar Hires
Fatality at Devil’s Ear
March 11, 2008
The recovery team compared notes and finalized our conclusions concerning the recent incident at Ginnie Springs. Our conclusions are based on the facts available and assumptions based on evidence retrieved from the victim and the equipment. While there are a number of scenarios that could be plausible only a few are consistent with the evidence we evaluated. The recovery team had both the expertise and experience with the equipment and diving style of the deceased to draw these conclusions.
Normally a recovery report is not followed by a summary such as this but we feel the nature of the incident and the impact to the local cave diving community warrants it.
The victim’s dive plan was extreme by any standards, go to the end of the line on a rebreather, remove it and proceed on with side mount thru some very tight restrictions to lay line and survey passage beyond the end of the line. Something every explorer wants to do. We feel he accomplished this because we found survey data and an empty reel on the victim.
The evidence supports the fact that he used more gas than he should have on the excursion after dropping the rebreather. The victim may have located and lined passage and surveyed it on a set of HP 100 steel cylinders at an average depth of 105’. Looking at the download off the computer and knowing the average time to get to the restriction we suspect he spent an hour beyond this point.
He returned to the rebreather chased by a cloud of silt which engulfed him and deteriorated the visibility for other teams in the cave system at the time. We aren’t sure of the sequence of events once he returned to the rebreather because of the state of the rebreather.
When leaving a rebreather unattended in a cave it should be handled like a stage bottle that is left behind, gas shut down and hoses secured. We believe this is not the case here, we think he left the oxygen bottle feeding the solenoid on and the set point left at .7 rather than being switched to manual so the solenoid would not fire. We believe he took little care in positioning the unit to keep moisture away from the sensors. The combination of the items above started a cascade of events to flood the loop in the hour he was away from the unit. The sensors got moisture on them and started reading low, the solenoid started firing to compensate, and the counterlungs filled and started burping air out the overpressure valve and taking in some water with every belch.
He returns to a flooded unit but may not realize it until he had it on, we assume this because he had connected the off board diluent back to the loop. At this point he uses the little gas he has left to flush the flooded loop and realized it was useless. Both bailout regulators were deployed and the wrist controller was dangling.
The visibility must have been zero and he was totally disoriented because the location where he dropped the rebreather and the 80 cuft safety bottle at the end of the gold line were only 50’ apart. There are some questions that can’t be answered.
Why did he take the time to retrieve the rebreather when a safety bottle was only 50’ away and he had three aluminum 80 staged in the system, plenty of gas to get back to the entrance. He would have still had to deal with a decompression hit since his bailout oxygen bottle was open and empty.
This was not a rebreather fatality but one of very bad choices. There is no training for removal and leaving a rebreather during a cave dive. The deceased had no formal training or experience to make the decisions that were made. He was CCR cave certified in November of 2007. This would indicate he did not have the experience needed to experiment with this type of dive. We suspect gas management on the side mount bottles was also violated, he had no formal side mount training. It’s the only way to explain not making it back to the 80 cuft safety bottle. Talking to other divers about the victim and the dive he was more interested in exploration than following the safety rules learned from the death of others. I write this only to let everyone know safety comes first.
After telling Dan Lins about the ordeal he summed it up for today’s cave diving fatalities.
“In the past we lost cave divers because we didn’t have the technology, today we have the technology but lose cave divers to lack of experience. “
Ginnie Springs is very concerned about cave divers visiting the park. Ginnie Springs Outdoors is a Recreational diving location. This type of site attracts divers with a variety of skill levels. It is extremely important we maintain Ethical cave diving to protect access to this site. Divers need to stay within the training standards set forth in the limits of Recreational Cave Diving.

When diving the Devil’s System be respectful of other divers, no digging, or any other activities that give concern to other divers such as a drop in visibility due to silting. Get back to basic conservation. Be respectful of the cave, no damaging the cave in attempts to create passage or make it larger. We must conserve what we have. If these recommendations are not adhered to there will be diving privileges lost. Privileges such as the ability to ride a DPV or cave dive all together.

We need to cave diving community’s help to maintain a safe diving environment for divers at all levels.

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you

DeepBlueInnovation

Thanks for posting. The analysis seems to validate the pattern of previous cave diving fatalities where divers exceed their training. Very tragic.

gottrimix

Thanks Mike

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Steve

www.lakemeadtechnicaldivers.com

USSMEG

Yes Thanks for the post. Eveyone always is interested in what was found and they did a good job with the details they found.

Paul

se2schul

Thanks for the report. There are clearly lessons that some of us might learn from. I find it's very rare that a thorough analysis is presented after an accident. Hopefully this will set a new precedent.

4ster

The Cave Diving section is part of the National Speleological Society. The NSS has a long tradition of publishing a nearly annual report "American Caving Accidents". It is a great resource for cavers seeking to improve the safety of their sport. The tone is factual and in many cases analysis is built on accident reports by participants. It would be a great model for building a report system called "American SCUBA Accidents".

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Steve
"My problem is that I have trouble reconciling my gross habits with my net income." Errol Flynn

Sutty

Thanks for the post Mike. Useful that a report has been made, useful in its principles for even non-cave divers. Not being an eccr diver I don't know whether I would have realised the need for the type of shut-down of an eccr if leaving it for a while (I'd realise a constant flow system like the Kiss needs shutting down). It does sound partly like a "you don't know what you don't know" problem - with tragic results.

Neil

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Never forget that life is a finite resource.

deedee

Which version of dump valve ingests water as it burps excess air ? What orientation does the valve need to be for this particular event to happen ?
I always thought positive preasure and correct orientation would prevent above scenario.
Is there a dump-valve that prevents this ?

Darek

doug allen

Can you imagine the horror this guy must have experienced?

It was said best earlier..."Dive within your training and experience."

Thanks for the information.

I'm very sorry for the pain the family must feel.

Drmike

Good question.

I would have thought that the only way water can enter a venting CL is if the pressure in the CL is equal to or below the ambient water pressure Wp.

As Wp acts on both sides of the OPV (CL isnt rigid) the effects of Wp across the OPV must cancel out. So we only need to concern ourselves with CL pressure falling to equal or below Wp - in other words we need to have a vacumm in the CL or CLp = Wp and a damaged leaking OPV is facing upwards.

I would have thought with a normally functioning OPV, on a venting system such as being described, water ingress can never happen as the CL internal pressure is governed by the opening forces of the expanding gas against the OPV (CLf) and the closing force of the spring. (Sf) The spring closing force limits the min CL pressure (in a continuous venting system) to something way above ambient. (how much above depends on spring force, but by definition it will always be above. Think how much it takes you to almost open an opv by blowing into your loop - thats how much +ve pressure you will have as a min in a venting CL)


Min pressure in CL (when OPV closes) is when CLf=Sf


So regardless of orientation I cant see how a properly functioning opv on a venting loop can ever let water in, and I cant see how a venting loop can ever flood (as by definition it is +ve pressure)

One way I can see it happening is ;

-OPV is damaged/leaking
-Venting uses up all O2 supply
-OPV slowly leaks out gas until CL pressure is same as water pressure
-The orientation of the Rebreather was such that leaking opv was facing upwards and allowed gas to bubble out and exchange with water.



Perhaps someone has some other ideas?

Either way I think its good practice to shut off feed and sit Rebreather down with opv at lowest point of loop.

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you