Mailing List Archive Mailing List Archive
Yes, there is truth to it. Here are a bunch of e-mails that were posted
to a local list. The list is an open list, so I feel it's OK to repost
them here, however I'm deleting the authors' names because I don't think
it's fair to drag them into the techdiver flamewar that is likely to
ensue.
I'm going to do this in two parts.
-Dave
Hello,
My name is <deleted>, a San Diego area technical diver
(Seadeucers will remember me as the guy with long black hair and the
double
OMS tanks, taking forever to surface!) The person that was injured is a
personal friend of mine, and not just a scuba diver, but an elite
technical
diving instructor. I will keep his name confidential, for that might be
his
wish, since his name was not mentioned in the Sunday paper or on the
news. I
have personally spoken to him over the last two days, and he is
currently in
the hospital undergoing a slow and painful recovery from 3rd degree
burns.
The cause of the flash fire that has injured him, is due to the
explosion of
the first stage regulator attached to his decompression bottle which he
was
about to use while giving instruction to one of his advanced students. I
repeat, the tank itself did not shatter, for this process would probably
have had even more adverse consequences... This explosion might have
been
caused by a contaminated first stage which once in contact with the high
O2
content (hot mix), has caused a rapid combustion during the oxidation
process which takes place when O2 comes in contact with O2 reactanting
contaminants. It was also confirmed, that the O2 has ignited his
drysuit,
from which he eventually managed to put off the flames by rolling
himself on
the ground!
This incident should not be taken lightly, and a very important
lesson is to be learned from this terrible tragedy! Anybody who is
qualified
to use high concentrations of Oxygen in their decompression mixtures,
generally 50% or higher, should use Oxygen Cleaned Tanks and valves,
with
Oxygen Compatible Components and O-rings. The regulators need to be
dedicated and O2 cleaned as well, and the parts need to be O2
compatible.
Should any of this rules be broken or slightly bent, and we are dealing
with
a ticking time bomb, just waiting for Murphy's Law to take it's course.
I
also recommend sealing off the first stages of regulators such as the
Atomics model, to minimize intrusion of contaminants by having them
injected
with Crystal Lube which is an Oxygen compatible sealant (It is best to
have
dive shops perform this operation). Please do not ever take a chance
with
high O2 mixes, for Oxygen is a very unforgiving, highly reactant gas,
which
will react with the slightest traces of contaminants, and in its close
to
pure state it is a fire/explosion hazard waiting to happen if not
following
oxygen handling standards. As technical divers we get educated by our
training agencies, about the proper handling of high O2, and pure O2
mixes.
However, accidents do occur and can unexpectedly happen even to the most
experienced and highly trained, without any exact explanation as to why
they
happen. It is our responsibility as divers/instructors to make sure that
all
the necessary steps are taken to minimize the risks that might otherwise
result into an unexpected fatality or accident. I will continue and I
hope
that we will all continue to pray for my friend's quick recovery from
this
ordeal. He is a genuine and dedicated, technical diving instructor,
educating divers on the many aspects of technical diving, increasing
their
awareness and confidence level in the open water environment. He has
plenty
of personal experience and a great desire to educate the technical
diving
comunity about safety, risk management, gear configuration and
expecially
for making good divers, better, safer divers. It is my understanding
that
this sort of accidents do seldomly and randomly occur, and it is not
always
an indication of neglect on the part of the individual, or lack of
qualification thereof. However, we must minimize the risks by educating
divers, and sharing the 'black box' knowledge, that has become Technical
Diving! Remember, the things that you do not know might kill you in
Technical Diving! Always seek higher education, if you have a desire to
get
involved in Technical Diving, and do not let others push you, or mislead
you
with false information that could be taken out of context. Qualified
agencies and instructors are available, and should be sought by
interested
parties for higher diving education.
I hope that this e-mail has answered any pending questions that
some
of you might have, however, if you would like to inquire about how my
friend
is doing over the next few days, please e-mail me privately at:
<deleted>. I am planning a hospital visit sometimes on Monday
afternoon whith another friend/fellow technical diver. Have many great,
safe
and enjoyable dives!
Thank You and God Bless!
<deleted>--
------------------------------
Hello <deleted>,
I am sorry, but my e-mail server has been down for part of the day.
To
answer your question, after doing a bit of investigation and after
talking
to John (the injured instructor) the mix would have been somewhere in
the
neighborhood of 75%-80%. This is a common mixture which 'technical
divers'
use for decompression, to offgass inert gases such as Nitrogen(N2) and
Helium (He). I have been informed that any O2 mixture above 40% will
cause
sparking to occur in contaminated/uncleaned regulators. This 1st stage
explosion must have been fueled by multiple factors, including the
possibility that titanium although durable, has a much lower ignition
point
in O2, than other alloys commonly used by regulator manufacturers. I
have
managed to call Scuba Pro to verify if my "Hot Mix" regulator once
serviced
with their Nitrox kit is 100% O2 compatible, and they told me that it
is.
Although I use Atomic regulators myself, I only utilize them on low O2
content mixes such as Trimix bottom mixes (normoxic-hypoxic), and travel
mixes containing 35% or less. I use three sealed Atomic regulators -
brass
models with titanium second stages on most technical dives. I know that
out
of the box, Atomic regulators can only be used with mixtures below 40%.
They
come this way already cleaned from the factory, and must be dedicated
for
nitrox use and never swapped, otherwise the whole cleaning process must
be
repeated by a qualified dealer/service center. The question still
pending in
my mind and probably in everyone else's mind is, can Atomic regulators
undergoing O2 service ever be used with pure O2? What about titanium
ones? I
am afraid that after this tragic incident which nearly costed John his
life,
I would not put too much trust in Atomic regulators with O2 content
higher
than 40%. I am still searching for answers and as soon as I find out I
will
post them up on the seadeucers e-mail list!
God Bless!
<deleted>--
----------------------
<deleted>,
there is one important factor that you have not included in your
analysis. I
understand the first stage in question was made out of titanium, and
this
material happens to be very high on a scale of propensity to ignite. My
guess would be that the ignition started at the interface between the
high
pressure seat and the piston knife edge, upon first pressurization. A
simple
seat ignition or an o-ring ignition with "regular" surrounding materials
(such as the common brass) would have resulted in nothing more than a
freeflowing regulator.
I agree that most people are taking nitrox very casually, inspite of the
recommendations by most manufacturers to use dedicated nitrox kits. The
latter replace the regular o-rings with Viton ones and the high pressure
seat with one made of O2 compatible materials. It is important to
respect
this. But in addition to these kits, one should use metals that won't
burn.
All the best to your friend, may he soon be back in the water.
<deleted>
--
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