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John,
Thanks for the update. Certainly my condolences go out to the family and
friends of Nic Gotto and the other innocent victims of the Inspiration.
K Irvine Wrote:
>We will see a lot more of this, John, until Rule Numbers One and Two
>get adhered to by more people out there. You guys all have to learn to
>call a liar a liar, and I will do it for all of you until you develop
>the balls to do it yourselves. I have good air cover as many of you have
>already discovered.
>Electronic RB's (CCRs) are death traps - do not belong in caves or wrecks,
>and do not belong in tech or rec diving, and should not be pushed and
>peddled to the masses, or used by the unsuspecting, or allowed in the
>hands of liars and scumbags who will let you get killed and call it your
>fault, or blame it on your diabetes.
John, we need to get the message out, not just on the Inspiration, which
is probably a good copy of the Cis Lunar, but on the use of closed
circuit electronic rebreathers in general. The people who push these
things either believe in their own lies or have such a huge financial
commitment to a failed concept that they cannot divulge the truth. If
you build an electronic rebreather you eventually learn about all of the
nuances and peculiarities inherent in such devices and eventually you
realize that to make one really safe is like the Heisenberg uncertainty
principle . The closer you get to a solution the more uncertain some
other aspect of the design becomes.
To summarize a few of the problems:
Protection of the o2 sensors from wetting or internal condensation.
Placement of the o2 sensors within the breathing loop for proper ppo2
assessment.
Addition of oxygen system and uniform mixing (pulsed or metered).
Scrubber design and placement of sensors with respect to the scrubber.
Diluent addition system.
Decision system (software/hardware) of when and how much o2 to add given
depth and sensor reading changes.
Sensor aging and non-linearity above ppo2 of 1 ata and compensation
(hardware/software) for this problem..
Integrity of Interconnection system of control, power supply (batteries)
and electro-mechanical addition of o2 and diluent and the ability to
resist aqueous invasion at interconnect points.
Many of these problems have been solved as best they can on the Navy's
MK 16, which probably costs the tax payers upwards of $40,000 a unit,
not to mention the very costly maintenance and r&d support program. The
MK-16 is a military device, not available to civilians, and it is used
within a high risk context to begin with. The electronic rebreather
gurus and socalled experts always throw out the example of the MK 16 and
other Navy rebreathers of why these things are safe. Don't be deceived
by this smug line of reasoning.
At first glance the description of the ensuing events leading up to Nic
Gottos death suggest that he may have succumbed to Hyperoxic o2
poisoning, following the very rapid excursion to depth. Bear in mind
that the Inspiration probably had a setpoint somewhere in the area of
1.0 +/- . Effectively the device was operating as an oxygen rebreather
at the surface. Descending suddenly to nearly 100fsw spiked his ppo2 to
nearly 4.0 ata. This extreme level, especially coupled with a high
cardiac output, will expose your cns quite rapidly to lethal dissolved
o2 levels. In a CCR the only way the o2 decreases within the loop is
through venting or physiological consumption of the o2. The ensuing
struggle in the face of a dangerously high ppo2 may have been the fatal
combination.
Maybe the Inspiration was flashing all of its alarms and displays. So
What? The problem as Irvine so correctly states is:
>Electronic RB's (ccrs) are death traps - do not belong in caves or wrecks,
>and do not belong in tech or rec diving, and should not be pushed and
>peddled to the masses, or used by the unsuspecting,
Our homegrown techno geeks perceive electronic CCRs as the ultimate
magic carpet ride. All the gas you can breath, even if you are a dough
boy or a chain smoking ectomorph, the playing field is leveled. If it
has no electronics and is not closed circuit these guys have no
interest. They do not want to hear about semi-closed rebreathers, which
at least overcome the risk of hyperoxic exposure and electronic control
uncertainty. If you think I am exaggerating just subscribe to the
rebreather list and hold onto your sanity. A real Alice in Wonderland
scenario populated with the Mad Hatter and lot's of white rabbits.
Best regards,
Bill Mee
Subject:
Inspiraion death - the facts
Date:
Tue, 28 Jul 1998 10:04:13 +0100
From:
"John Grogan" <john@ro*.co*.uk*>
To:
"rebreather" <rebreather@nw*.co*>
CC:
"cavers" <cavers@ca*.co*>, "techdiver"
<techdiver@aquanaut.com>
The following are the events that led to the death of Nic Gotto whilst
using the Buddy Inspiration
rebreather unit.
Nic ran Sundancer II Charters out of Union Hall in Cork (South coast of
Ireland). He was a very
experienced diver and skipper. A number of weeks back, Nic purchased
the Inspiration and attended a
TDI weekend rebreather course. I've been informed that the practical
aspects of this course consisted of
a 1 hour pool session, a 45 minute dive and 1 change of scrubber
sofnolime - this is on top of the usual
lectures and theory.
On Saturday, Nic and 3 other divers went to the wreck of the Kowloon
Bridge (second largest wreck in
the world). Nic was with a buddy and the other 2 dived together. I do
not know if Nic's buddy was using
an Inspiration or OC. Whilst diving at a depth of 10m (ppO2 1.3 bar),
Nic encountered a down-draught
that almost immediately swept him to 25m (assuming same fraction of
oxygen ppO2 2.3 bar). An oxygen
toxicity hit occured. (I can only assume that the unit did not respond
to the increased ppO2 in time and
that Nic expended a lot of effort getting out of the down-draught). His
buddy tried to assist and in the
struggle lost his weight belt and mask. Buddy came to the surface,
alerted the dive boat and was given
another mask. He pulled his way down the shotline and found the other 2
divers. The situation was
indicated to them and they commenced a search.
Nic's body was found and a rescue commenced. At about 20m, Nic inverted
in his drysuit and at about
14m contact was lost with him but he went to the surface. At the
surface, these divers cut him out of the
harness. As they knew nothing about rebreathers, they didn't close the
loop. Subsequently, the loop
flooded and the unit sank back down to the seabed. Nic was pulled onto
the boat and blood was found
foaming in this mouth. Boat crew immediately commenced AV and CPR for
45 minutes at which point the
lifeboat arrived. Nic was declared DOA.
Army and civilian divers and currently searching for the unit that Nic
was diving. I sincerely hope that
no-one tries to pin the blame on any of the 3 divers in the water at the
time. They made a vallient attempt
to save Nic, but unfortunately it was stacked against them.
To date there have been 3 fatalities and 2 resuscitations with
Inspiration divers. There have been about
120 units sent out and about 250 people trained on the unit. That's 5
serious/fatal incidents for 120 units
(4%). There has been in the UK what I can only describe as a conspiracy
of silence regarding the
Inspiration and more particularly the indicents encountered. I spoke to
one diver yesterday who owns 2
units - he is fuming at the lack of information forthcoming and refuses
to use either unit until there is more
openness on it's failures and proper training.
David Shimell posted earlier on this and pointed out 3 main causes for
the incidents:
>1. Equipment design or failure.
>2. Poor training.
>3. Poor vetting of candidates for training.
I think 1 & 2 apply. Certainly 2 of the deaths and 1 of the
resuscitations were very experienced divers.
Why do some agencies seem to think that a 2 day course can impart all
the information required to safely
dive a rebreather? The Navy spends months training their divers on a
unit!
I am sure there will be a full police investigation into this matter and
as I receive more information, I will
post it to the list.
Regards,
John Grogan.
John Grogan wrote:
>
> The following are the events that led to the death of Nic Gotto whilst
> using the Buddy Inspiration rebreather unit.
>
> Nic ran Sundancer II Charters out of Union Hall in Cork (South coast
> of Ireland). He was a very experienced diver and skipper. A number
> of weeks back, Nic purchased the Inspiration and attended a TDI
> weekend rebreather course. I've been informed that the practical
> aspects of this course consisted of a 1 hour pool session, a 45 minute
> dive and 1 change of scrubber sofnolime - this is on top of the usual
> lectures and theory.
>
> On Saturday, Nic and 3 other divers went to the wreck of the Kowloon
> Bridge (second largest wreck in the world). Nic was with a buddy and
> the other 2 dived together. I do not know if Nic's buddy was using an
> Inspiration or OC. Whilst diving at a depth of 10m (ppO2 1.3 bar),
> Nic encountered a down-draught that almost immediately swept him to
> 25m (assuming same fraction of oxygen ppO2 2.3 bar). An oxygen
> toxicity hit occured. (I can only assume that the unit did not
> respond to the increased ppO2 in time and that Nic expended a lot of
> effort getting out of the down-draught). His buddy tried to assist
> and in the struggle lost his weight belt and mask. Buddy came to the
> surface, alerted the dive boat and was given another mask. He pulled
> his way down the shotline and found the other 2 divers. The situation
> was indicated to them and they commenced a search.
>
> Nic's body was found and a rescue commenced. At about 20m, Nic
> inverted in his drysuit and at about 14m contact was lost with him but
> he went to the surface. At the surface, these divers cut him out of
> the harness. As they knew nothing about rebreathers, they didn't
> close the loop. Subsequently, the loop flooded and the unit sank back
> down to the seabed. Nic was pulled onto the boat and blood was found
> foaming in this mouth. Boat crew immediately commenced AV and CPR for
> 45 minutes at which point the lifeboat arrived. Nic was declared DOA.
>
> Army and civilian divers and currently searching for the unit that Nic
> was diving. I sincerely hope that no-one tries to pin the blame on
> any of the 3 divers in the water at the time. They made a vallient
> attempt to save Nic, but unfortunately it was stacked against them.
>
> To date there have been 3 fatalities and 2 resuscitations with
> Inspiration divers. There have been about 120 units sent out and
> about 250 people trained on the unit. That's 5 serious/fatal
> incidents for 120 units (4%). There has been in the UK what I can
> only describe as a conspiracy of silence regarding the Inspiration and
> more particularly the indicents encountered. I spoke to one diver
> yesterday who owns 2 units - he is fuming at the lack of information
> forthcoming and refuses to use either unit until there is more
> openness on it's failures and proper training.
>
> David Shimell posted earlier on this and pointed out 3 main causes for
> the incidents:
>
> >1. Equipment design or failure.
> >2. Poor training.
> >3. Poor vetting of candidates for training.
>
> I think 1 & 2 apply. Certainly 2 of the deaths and 1 of the
> resuscitations were very experienced divers. Why do some agencies
> seem to think that a 2 day course can impart all the information
> required to safely dive a rebreather? The Navy spends months training
> their divers on a unit!
>
> I am sure there will be a full police investigation into this matter
> and as I receive more information, I will post it to the list.
>
> Regards,
> John Grogan.
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