Hallo,
nun nochmal hier,
wahrscheinlich zum ersten Mal auf einer deutschen Liste.
mit ausdrücklicher Unterstützung des Authors diesen Vorgang als Crosspost zu verbreiten,
in bester Absicht, nichts zu vertuschen und das mögliche Zusammenspiel kleinerer Versäumnisse zur adhoc lebensbedrohlichen Situation noch einmal zu verdeutlichen.
Besten Gruss,
Hoffi
_____________________________________________
MAIL VOM 02.04.2007:
WKPP Team
Our plans to explore west and restock/reposition safety tanks in Wakulla
Springs were postponed yesterday due to an unexpected incident involving the
primary setup team of Mark Garland and John Rose. We are in the process of
completing a complete review of the incident and will communicate the
upcoming schedule as soon as possible. A complete review will involve
assessing the current procedures, including incident response; I am working
with our project engineer, training director and project coordinators to
consider changes to our procedures and response plan where deemed necessary.
In summary:
At approximately 7:45am on Saturday morning the primary setup team of Mark
Garland and John Rose departed for the cave entrance. The team descended on
rebreather while on 190 gas with a moderate payload of equipment. John Rose
led the way toward the ledge at 25ft; from this ledge the water drops
directly to 130ft. Approximately one minute after departure and before
reaching the ledge Mark Garland lost consciousness. John immediately noticed
the problem and quickly grabbed Mark, bringing him to the surface. Mark was
transported to nearby support personnel. Mark was quickly extracted from
his equipment and moved to the beach area. Support personnel confirmed he
was breathing and had a strong pulse; he was immediately placed on oxygen
with Wakulla County EMT arriving several minutes later. Mark was quickly
transported to Tallahassee Memorial, stabilized and then transported to
Tallahassee Community in case it was determined chamber treatment was
necessary. During this time WKPP support personnel were coordinating with
EMS, DAN and Gene Hobbs at Duke University; these procedures have been
designed to minimize delay of appropriate treatment. Mark has made an
excellent recovery; he is alert and responsive and has quickly regained a
good sense of humor.
After completing a more comprehensive accident analysis we will communicate
our findings to the community. Preliminary review confirms correct gas
content labeling and all equipment appears to be configured correctly; we
will conduct a careful review to ensure the equipment is functioning
correctly. John Rose has noted current environmental conditions (low water
and high plant growth) force departing teams to stay high and scooter
farther to the reach deep water. However, given the short time involved we
remain suspicious about the cause of this accident. WKPP rebreather divers
have been using this route and procedure for more than ten years. Therefore,
extensive review is needed before speculation about the cause of the
incident can be considered productive. Per normal team procedures all
questions or inquiries should be directed to me and team members should
refrain from public comments and speculation.
Having been involved with the WKPP for almost 13 years, I recognize the
nature of our diving involves a great deal of complexity; ultimately this
complexity translates to additional risk. Over the years we have been very
successful managing this risk and we take any sort of injury very
personally. How we prepare and ultimately respond will make the difference
between success and failure. I am proud of each team member on site; you
each executed your responsibilities flawlessly and the emergency plan worked
as designed. Also, a special thanks to Gene Hobbs who was in the loop within
minutes, coordinating between DAN and the Tallahassee medical teams. We are
also grateful to the Tallahassee medical teams for their outstanding
attention to detail. As additional details become available I will
communicate to the team list.
Best,
Casey McKinlay
Project Director
Woodville Karst Plain Project
____________________________________
MAIL VOM 12.04.2007:
WKPP Diving Incident - Analysis
Senior WKPP team members have completed a thorough analysis of the March 31
incident. Our assessment carefully reviewed all relevant WKPP procedures as
well several noteworthy areas including: the spring environment, diving
equipment, breathing gasses and EMS response. The investigation also
conferred with State Park officials regarding future procedures and local
support.
The WKPP has managed an impressive safety record while pursuing some of the
most complex dives ever organized; yet, we recognize that changes in
technology, team composition and general dive complexity require a regular
willingness to adjust our procedures where a better approach can be safer
and/or more effective.
The WKPP internal analysis did not uncover a single unique cause of the
March 31 incident; instead a combination of events appears to have initiated
this shallow water, hypoxic event, occurring as one of our rebreather divers
began a descent from the surface.
Report Summary
Environment
Our findings indicate excessive plant and hydrilla growth complicated a
normally easy descent to depth. In this case, the existing path did not
allow for a clear approach from the surface to the spring basin. A hydrilla
treatment the week prior to the dive was beginning to take effect on the
invasive plant. This caused the plant to dye off, allowing it to clump in
large bunches around the spring basin; this also occurred within the normal
ingress/egress area for divers. This debris required divers to take a
shallower, indirect approach to the spring basin; this ultimately delayed a
more direct descent to deeper water.
Equipment
Gas Venting/Addition
The RB80 was functioning properly; however, it was discovered that the diver
had incorrectly installed the aluminum bellows addition plate upside down
and without the inner bellows o-ring. This scenario allows a small volume
of gas to pass between the inner and outer bellows, affecting the portion of
gas vented to the ambient water. Ultimately this can cause a faster
reduction in one's PO2. The equipment configuration mentioned did hold a
vacuum in pre-dive testing but ultimately contributed to less than complete
venting of the loop. While at depth the PO2 drop seems negligible. However,
it is obvious that divers must use greater care in ensuring proper assembly
and function.
Addition Regulators
Both gas addition valves were in need of servicing; this limited the
efficiency of the addition regulators. The diver confirms manually
adjusting the second stage orifices pre-dive to reduce a developing
free-flow; this ultimately reduced the ease with which fresh gas flowed to
the counterlung. Again, this problem creates a noticeable but not
problematic O2 drop when working with greater total oxygen concentrations.
Operation
The rebreather and open circuit system were functioning properly and
configured correctly. The diver's 190 descent gas was correctly plugged into
the switchblock; the backgas was not plugged into the switchblock per normal
procedures; the unit was vented following pre-dive assembly, the inner and
outer bellows were not damaged in any way and the OPV was functioning
correctly.
Breathing Gas
The diver correctly plugged in 190 decompression gas for descent from
surface; he was following descent venting procedures. Post-dive gas analysis
confirmed 17% oxygen and 49% helium in the mix. WKPP procedures call for a
maximum 21% oxygen content within the 190 decompression gas. While 17%
oxygen is slightly lower than the ideal mix, this alone should not have been
a problem.
Support and Response
Surface support responded swiftly once the diver was brought to the surface.
The diver's partner is credited with an impressive response, emphasizing the
importance of operating as a team. The WKPP believes this to be the single
most critical factor in all diving operations, including successful
resolution of this incident.
WKPP Procedural Changes
Environment
Pre-dive clearing of ingress/egress area to allow for a clear path to the
spring basin and cave entrance. Park officials have agreed to assist as
necessary.
Equipment
RB80 assembly - complete team overview of assembly procedures for RB80 units
with emphasis on critical components.
RB80 maintenance - emphasis on encouraging RB80 owners worldwide to schedule
yearly or as needed maintenance through local dealers or Halcyon Mfg.
Breathing Gas
Clarify difference between 190 decompression gas and 190 support gas; 21/35
is our decompression and transition gas while support and diving gasses are
our standard 18/45.
Change rebreather descent procedures to require open circuit descent while
using 190 decompression gas (21/35) to a depth of 50ft at which point the
diver can switch to rebreather and stow second stage regulator on drive
bottle.
Support and Response
Add open circuit escort team for rebreather divers descending from the
surface to 50ft. The open circuit team will escort each rebreather team and
assist as necessary during the descent to the cave entrance. The team will
remain in the water until the first team returns from its planned mission
and normal decompression support operations begin.
Add two support team members for shallow water surface support to assist
divers as they enter the water and prepare to depart for missions within the
cave system. Both divers will have mask/fins available to assist with any
shallow water support needs.
Add support team member to dive tower at Wakulla Springs to monitor teams as
they depart the beach area towards the spring basin and cave entrance.
Summary
The WKPP believes the following changes and improvements will further
enhance our ability to safely and effectively manage exploration and
research support within the cave systems of the Woodville Karst Plain. We
recognize that we cannot plan for every eventuality and much of what we do
has no blueprint to follow; however, we can and will adjust policies to
reflect the safest possible procedures. I believe each and every team member
makes safety, awareness, buddy skills and attention to detail a priority and
I expect the entire team to take it to the next level this 2007 season. I
look forward to seeing everyone later this month as we resume operations on
April 21-22.
I would like to thank those that have reached out this past week and offered
assistance and expressed support for the team. I would also like to point
out that this information should not be considered confidential and will
benefit divers, project leaders and rebreather users worldwide. The WKPP
has contributed a great deal over the years to technical diving, team diving
and project planning and logistics and we will continue to do so going
forward.
Casey McKinlay
Project Director
Woodville Karst Plain Project
