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Incident Date: April 18, 2014
accident Time: 15:00
victims: Wang Tao, male, aged 34 years old
survivor: Wang Yuan, male, age 32 years
diving type: cave diving
maximum depth: 166 m
cave status: An Daxing Jiu Dun Bei Dongxue (安大兴九墩北洞穴
cave entrance Depth: 18 m
Maximum depth: over 170 m
cave morphology: ladder
usually Visibility: 5 meters
visibility day of the accident: 2 m
water: Weak
Water temperature: 19 degrees
Dive Objective: To conduct a large 170m deep cave diving exploration
divers Information:
Wang Tao
Divers Level: WUD CAVE 2, UTD CAVE 2, NSSCDS FULL CAVE, GUE T1
cave diving Start Date: 2009
Cave Diving Experience: 200 +
for the first time in a cave diving accident date: 2010
cave dives in an accident : 15
had the largest cave diving depth: 122 meters
across the longest distance ever: 1,000 m
cave diving: China, the Philippines, Mexico, the United States
Wang Yuan
Diver level: WUD CAVE 3, PSAI / NSSCDS FULL CAVE, UTD / NACD CAVE DPV, TDI CAVE REBREATHER / ADVANCE TRIMIX
cave diving Start Date: 2008
Cave Diving Experience: 400 +
for the first time in a cave diving accident date: 2010
in cave diving accidents: 15 +
had the largest cave diving depth: 122 m
Maximum Open Water diving depth: 150 m
once the longest crossing Distance: 3000 m
Cave Diving: China, the Philippines, Mexico, the United States, France, Portugal
Zhou Pei
Diver level: WUD CAVE1/TECH 1
cave diving Start Date: 2013
cave diving experience: 15
first dates in cave diving accident : 2013
in cave diving accidents: 3
had the largest cave diving depth: 51 meters
maximum open water diving depth: 63 meters
across the longest distance ever: 100 m
Cave Diving: China, Philippines
dive plan:
plan to use an underwater gas volume / Principle 3
largest planned depth: 170 m
maximum planned underwater time: 20 minutes
Expected decompression time: 3 hours 50 minutes
Division: Wang Yuan is responsible for leading the way and continue to guide the rope, Wang is responsible for layout arrow, up Wang Yuan is responsible for guiding stay
decompression program : From 84 meters to start stage decompression, deep stage using BULHMAN form, the latter half of decompression theory using the bubble
gas options: stay underwater because time is short, so to accept a slightly higher oxygen partial pressure, to shorten decompression time. Underwater nitrogen gas to maintain proper levels to avoid HPNS, switch gas helium content decreases avoid IECD
direction: cave extends to the northwest
of risk analysis; low visibility needed to guide rope near large depth need every minute to see barometer, leakage and lighting faults
placed ahead of 21/35 at 57 meters, EAN35 at 50 meters (depth of 36 m switch), EAN 50 at 21 meters, O2 at 6 m
dive - hang boot 75 meters using 18/45, 75 m to remove 18/45 ropes, switch to the first stage of cylinders 8/70
completed the first phase of the gas cylinder using a switch to the second phase of the cylinder, and finally use the master cylinder. (Wang Tao oxygen cylinders because one stage was 10%, scheduled to start at the rise in the 150 meters when using) because of depth, time constraints, so the prior agreement of their own switching stage cylinders, cylinder makes switching stage cross-checking. Pressure cylinders only when switching to cross-check
The accident:
1, Background:
since 2010 for the first time in nine piers cave diving, Wang Tao and I have been obsessed here, graceful plants and a steady stream of smoke from the underground springs We attract visitors again. From the first 40 meters depth, and 55 meters, 75 meters, 90 meters up to 122 meters, we are here in the south outlet, the outlet and the outlet of the North under the stairs several times diving. We hope to find a channel level, which is where the main underground river waterways. Here's visibility even in the winter can reach 15 meters deep underwater tunnel that attracts us increasing depth. I and Wang Tao in Meizhou early this year after the start brewing a cave dive deeper dive. But for this area, there are many unknown factors, the biggest problem is the pressure aspect and physical condition.
March 2014, the French cave diving staff PASCAL (diving world record holder) north of the pier will be nine questions outlet Ropes extends to 160 m depth, learned this news, I had come to ask the cave dive in Guangxi. I usually use the RD scheme diving, but I only used RD diving 120 meters or less, and I hope to get some helpful information from him to develop a reasonable decompression program.
PASCAL provide help when in doubt. Under his proposal, we plan to combine theory and bubble dissolution theory.PASCAL Metropolitan divers also mentioned physical problems in more than 170 meters after, including HPNS, when a sudden rise in coma and decompression sickness, and so on. Because this form of decompression depth study imperfect, but less than 170 m is relatively safe. I asked in detail about the PASCAL himself down to 160 m deep cave diving, I ruled out the possibility of the loss of visibility of the cave, also confirmed the orientation and size of the channel. Subsequent studies assessed Tao and I think to dive into the depths within 170 meters of the planned dive assessed as complex but not difficult dive, so I developed a plan and Wang Tao continues to extend the depth of 170 meters to the main rope.
Plan, develop quickly prepare equipment in place. Because no more than 125 meters Tao diving experience, I told Wang Tao so he told me to Cebu, Philippines to conduct a 150-meter open water dives. But because of work arrangements Wang Tao, he did not have time to train in Cebu, so we finalized after consultation directly test dive in Guangxi, the best results are planned to reach 170 meters, but the actual arrival depth look at the state of adjustment.
April 15, I come back from the Philippines and Wang Tao, Zhou Pei confluence of three arrived in Guangxi, as heavy rains cause visibility at around 2 meters. We first conducted CHECK DIVE a depth of 75 meters, found the water is not strong, will not affect the decompression stops and increase resistance to enter the cave. Although visibility is about two meters, but not a big cave tunnels, many times before in this cave diving, have encountered low visibility conditions, we are very familiar with the position of the guide rope, so we will not have much impact assessment that. After two days, we need to practice to do some diving programs, such as rotation and switching cylinders and so on. And careful deployment of the required twenty diving cylinders. One day before the dive performed, the three of us all together laying water pressure cylinders and record together again to discuss the dive plan. Everything is ready, waiting for the completion of diving into the water. I am excited and Wang Tao in addition to outside without any tension.
2, dive equipment inspection after the completion of the water, I began to dive and Wang Tao, check the cord along the way to check the label and residual gas pressure cylinders, we successfully reached 75 meters deep and hung 18/45, to switch to the first stage cylinder, then Wang Tao lights motioned me, my primary stage cylinder head interface leak, I close the cylinder, re-tighten the level head, open it again, the leak stops (Tao diving can be determined at this time the state normal). At this time is about 12 minutes underwater.
Then we continue to dive along the access ramp, when encountered at 100 m area of low visibility, visibility about 50 cm, and soon the area through low visibility, visibility restored to about three meters, we continue to dive to 120 meters, each check status, make sure everything is normal after the two sides continue to dive . I switched at about 150 meters to the second stage cylinders, according to Wang Tao, the original plan to switch to the main tank, and then we reach 164 meters, Wang Tao, an arrow in the boot绳布home, I continued to probe a bit down the channel direction. Then my END approximately at the level of more than forty meters, and breathing some acceleration, feeling slightly anesthesia, and Wang Tao stands to reason I should not have no clear feeling, because we have done many times in open water 75 meters air diving exercises, including night dives. Tao was being arranged arrows, normal visual state.
3, up (throw rope) about 1 minute or so we have started to rise, then the entire dive time is about 21 minutes. When I rise in the second stage of the remaining cylinders 130bar. When it reaches 130 meters, visibility is only two meters, I was choking happened guide rope knots at no continuity.Guide rope was gone! ! ! My heart is now cold, and Wang Tao as a bit later, I decided to take immediate action, the use of the channel is characterized by rising terrain oblique annular search guide rope along the wall (because at this depth, the gas consumption is very fast, no time Fixed line tied the knot again). We deal with emergencies left time is running out, this time, I felt nervous and Wang Tao, but we did not have time to be afraid, I have to do is take advantage of the terrain to find the guide rope as soon as possible. About 2-3 minutes or so we found a guide rope drawn to the cave in the middle of the channel, my heart hung immediately put down.
4, shared gas after guiding the rope to find, when I have exhausted the second stage bottles, switch to the main cylinder continues to rise. When it reaches a depth of about 120 meters, I suddenly felt light shaking, I looked down and followed my Tao card in a protruding rock, he will light against his neck, indicating no gas coming, cool action correctly. Wang Tao gas actually consumed so quickly that I was surprised, I instinctively action to immediately give the long hose to his mouth, and then expand the long hose, they began to rise symbiotic breathing. When I see their pressure, only 130 or so, I quickly estimate the depth of the gas a bit in this, can only support two divers nervous about 3-4 minutes time, suddenly feel the pressure with unprecedented. So I immediately gave rise Tao gesture, he calmly responded to my gesture with OK, the two began to rise. I put a barometer on his chest at any time convenient viewing. Due to volume restrictions, I decided to rise to a total of 75 meters as soon as we put pressure cylinders at the stage of examination to exclude issues do. So we started to rise along the Size of the pull speed, there's very far away from our first vacuum bottle, I knew had to speed up the job. Contact with my left hand to guide the rope, to avoid losing guide rope, looked avoid projecting rock, Wang Tao took my right hand side rising barometer in the rapid decline in the rapid rise, it makes me feel not clear.
5, lost friends when at around 90 meters, I held onto the rock left hand, right hand with a light shining depth and pressure, and the remaining 40 pressure, but from the stage of the bottle is only about 15 meters, the danger will soon be eased. Just then I saw Wang Tao upward drift sideways, I subconsciously reach out and grab him, and did not catch, and then looked up, I already see him disappeared, along with a long hose fall, that process is one second Bell, the moment! I do not see any struggle Tao and I tried to grab or catch or catch Ropes rock act. I realized the situation, and immediately picked up a long hose along the rope caught ten meters did not find him, because little gas low visibility, I can not leave the guide rope looked to find, when I began to sense is not clear, feeling of dreaming, close your eyes, I energetically shook his head to calm myself, try deep breathing, but felt the breath of increasing resistance, check their air pressure again, only about 20 or so, and then I went to 75 meters, to find the place of 18/45, and switch quickly open the cylinder, then 18/45 hanging in the body.
6, looking back into the cylinders, I began to realize the seriousness of the matter - my best friend Tao in trouble! Hundreds of millions of times the sense of isolation suddenly struck, I told myself in the heart, we must find him, be sure to take him out of the hole. I immediately covered the lights to see if he could see the lights, then, the cave a quiet, familiar roads seem to have changed like I had five times to reach 75-85 meters this should be very familiar with this segment substantially vertical downward, where Wang Tao go? I keep looking in the cave along the rope for a few minutes, then check the air pressure is only 40 (because the vanguard ever used), I decided to get my 21/35, I did not use Wang Tao placed in 75 m of 18/45, I naive to think that if he can return to the cylinder can also be used, then went to 57 meters, will use an empty stage cylinders hanging on the ropes, took my 21/35, hanging in the body and return to the deep after switching to look at, I was very clear I can not more than 66 meters of gas, then I have only one thought: I want to find Wang Tao, he was hurt, and I do not want to live alone. I dive along the rope, covered my light, looking for his light, I feel more and more vague sense, subconsciously pressure constantly looking to see depth, 70,80,90 meters. I tried to feel the feeling of oxygen toxicity, my mind constantly emerging to teach a class to teach students like symptoms of oxygen toxicity signs, I think if I twitch can accompany the dizziness passed Tao go. To 90 meters, I think back to Tao look around the accident scene, was on the verge of collapse, the moment I seem to syncope in the past, without any consciousness and awareness. When the pressure is only 60, survival instinct forced me to start fast rising to 50 meters, took my EAN35 hanging in the body, back to the 36 Mitch change, I should start decompression stop at 84 meters, 75-57 meters should stay 7 minutes at 57-36 meters should stay 14 minutes, but then I have not completed stay calm, I like to ignore all stay irrational rise in support for all divers want to tell what happened Zhou Pei soon. Fast rising from 36 meters to 21 meters, Zhou Pei finally saw the light.
7, Survival (part after citing Zhou Pei narrative) after the confluence with the support divers Zhou Pei, I motioned for him Tao and I separated, and he was very surprised, I called directed at underwater, when the Zhou Pei unacceptable so cruel The reality, he did not bother me, alone, trying to find the Tao dive along the rope trail. After seeing Zhou Pei, my mind begins to relax tense, about 1 minute later, I felt a rock at 21 meters rotate 360 degrees in front of me to die, grab the rock, feeling the whole person in the rotation, I see Zhou Pei returned to find me, I grabbed him and told him I had a problem, he began to take me to rise to 18 meters, but the pain in the leg joints occur, reminded the state now, I know for sure is rising rapidly lead to nitrogen and helium bubble expansion in the body, I have to go back to a place of deep pressure, I motioned Zhou Pei down, so he escorted me back to the beginning of stay 36 meters, when the pain is gone, I grabbed the rock, but the head is still faint, Zhou Pei Wang Tao is still trying to find, I motioned for him I die, let him look at me. At that time, I realized that death from getting closer. I'm trying to find the reason I now state, I listen to your body, I guess is fast rising, swelling caused by nitrogen bubbles? Or oxygen poisoning symptoms? Or inner ear decompression sickness (IE CD)? I do not know, I want to increase the depth stop to relieve dizziness, but no effect, Zhou Pei help me start up slowly, in 33 m 30 m 27 m and 24 m completed a stay about 20 minutes, followed by Zhou Pei brought me up on 21 meters EAN50, then dizziness intensified, felt nausea, nausea. I soon began to vomit. I was so weak, but still tried to make her breathe, I suspect that oxygen poisoning, I switched back to the long throat, trying to breathe hypoxic gas to relieve symptoms, but did not improve, I switch back to the EAN50, then I started to cramp intermittent , I motioned Zhou Pei took me to stay 18 meters, he started up with me, convulsions, I desperately grabbed him, heart told me to breathe, every time a little better, I would look at the time, to see the depth, I If you do not know after the completion of all stays, Sheung Shui, I will die. Pei in the water next week, he motioned for me to call for help in Sheung Shui, I grabbed him, let him not leave me, because I know Tao has been unable rescued, and I'm dead line struggled, unable to control their own depth, once the week Pei leave, my life will be over. So Zhou Pei continues to rise with me, my limited awareness of the limitations in breathing, rope, time and depth. I am using willpower to stick, doing all to complete the remaining stay. Because the body upright, tumble all the exhaust gases, I began to feel cold, try to charge point tumble in the air, increasing warmth, but up and down repeatedly has consumed all ARGON BOTTLE, I can not afford to switch to the master cylinder to tumble inflated. When up to six meters, the Zhou Pei switched pure oxygen to help me, and help me to switch every 20 minutes hypoxic gas to prevent oxygen poisoning. At 6 m stage, I have basically lost consciousness, confused, and then felt someone shoot me, opened my eyes and saw Zhou Pei asked me if OK, a look at the table 10 minutes later, after a while not fully awake, Zhou Pei I woke again, so, after more than an hour, I decided to tell all premium Zhou Pei underwater occurred. Zhou Pei took me slowly to the surface, I simply told what had happened, Zhou Pei called the police and informed the crowd of 120. I felt pain in his right arm this time, I know that we must continue to stay again into the water, I let Zhou Pei accompanied me back to a depth of about four meters, the pain began to ease, we stayed for 20 minutes or so liters of water, then the pain disappeared, but still dizziness and nausea. Our total decompression time is approximately 150 minutes (planned decompression time is three and a half hours).
