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British divers make contact with missing Thai football team

theguardian.com

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Re: British divers make contact with missing Thai football team

#61

Post by JshWright »

cm2187 wrote: post #51
jaggederest wrote: post #14

Earlier quoted context omitted.

It's interesting, I wonder what the pros and cons are for drilling to retrieve them or send supplies. In the mine collapse situations that I'm aware of, there was already infrastructure on hand for heavy equipment and drilling. I have to imagine that the dangers of cave diving are multiplicative - you don't get enough skill-based improvement from any given trip into/out to make repeated trips a safe option.

Stupid question. If you manage to drill down to the cave, don't you pierce the air bubble that prevents the water from rising and flooding the cave?

Caves are quite permeable. It's not air pressure holding back the water, it's just a matter of how much water there is (the cave goes into the side of a mountain, it doesn't just go down into the ground).

Re: British divers make contact with missing Thai football team

#62

Post by A_Person »

draugadrotten wrote: post #38
dm319 wrote: post #25

This is great news, but sadly their lives are still very much at risk. They are too deep to drill down to, there is a lot of rain to pump out (and the rain can continue), and they can't swim (even if they could, this is a hard dive for those that can). Found this from a Bill Whitehouse: Bill Whitehouse, vice-chair of the British Cave Rescue Council which is helping the rescue efforts, played down speculation the boys…

As an experienced cave diver, I agree with Mr Whitehouse that bringing them out as "packages" should be considered an option. It would be easier than allowing them to swim by themselves in murky waters with no vision. The diving training spoken of might be getting the boys to be used to being towed under water while being packaged up, rather than about teaching them about buoyancy control like adult divers.

You can't be serious. Taking 13 people, with an absolute maximum of Open Water level training (if that), back out through hundreds (or thousands?) of meters of low or zero visibility diving, including (apparently) tight restrictions, without risking the lives of all concerned? Aint gonna happen - unless the water level drops to the point where they can just float back out.

Re: British divers make contact with missing Thai football team

#63

Post by ljcn »

braythwayt wrote: post #57
jdietrich wrote: post #44

Earlier quoted context omitted.

It's skill rather than bravery. Rick Stanton and John Volanthen were the divers who first made contact with the missing boys. They are both hugely experienced cave divers and cave rescue divers; as a team, they have broken multiple records in depth and distance. This was a difficult and complex diving operation, but that's business as usual for divers of this calibre. Bravery is fundamentally incompatible with cave d…

I fundamentally agree with where you are going, but like another responder, I think that we have different understandings of the word "bravery." Hollywood's idea of "bravery" is really recklessness. And that is absolutely incompatible with cave diving, as it is with racing automobiles, fast and light alpine climbing, and other activities where training and judgment keep you alive. But as this is not a Hollywood movie…

It seems to me that the "Hollywood bravery" you nicely describe really is bravery - Oxford Dictionaries says the word comes from French braverie or Italian braveria (boldness), based on Latin barbarus (c.f. barbarous). Alternatively it may be from bravo (wild, savage).

Courage on the other hand comes from Old French corage, from Latin cor (heart).

I think based on this the divers are courageous, not brave.

Re: British divers make contact with missing Thai football team

#64

Post by SagelyGuru »

fabricexpert wrote: post #32
SagelyGuru wrote: post #20

"None of them can swim" Great idea to take them down into a flooded cave in rainy season. Even though now found, they will still be very lucky to get out alive. How? I think it is the case of learn to swim and dive right down there or die. Whatever was their coach thinking?

Personally I think the coach should be commended for keeping all those boys safe and alive in such conditions. He couldn't have known the cave was going to flood, the signs say don't go in in between July and September - they entered in June. Without a strong leader this probably would have been a very different outcome already and they'd be dealing with retrieving corpses. I actually find comments like yours really…

I assume it was his decision to take all those children down there, so it was not beyond his control. Did he at least check the weather forecast?

If my comment was designed to provoke, then it was to provoke people to think. We need to be able to think for ourselves sometimes.

I actually find your comment somewhat unhelpful and grating. It is all very well everyone being a hero and never admitting to any wrong decisions but that is exactly the sort of attitude that leads to these situations and to their repetition. If nobody has done anything wrong, there is nothing to learn.

Re: British divers make contact with missing Thai football team

#65

Post by CloudNetworking »

arethuza wrote: post #40
CloudNetworking wrote: post #37

Earlier quoted context omitted.

That's not a weird phobia by any means. That's very common and it's called claustrophobia.

I'm not afraid of small enclosed spaces (e.g. in a building) - I'm afraid of caves :-)

Cavephobia! ;-)

(as others point out, it's probably the same)

Re: British divers make contact with missing Thai football team

#66

Post by braythwayt »

ljcn wrote: post #63
braythwayt wrote: post #57

Earlier quoted context omitted.

I fundamentally agree with where you are going, but like another responder, I think that we have different understandings of the word "bravery." Hollywood's idea of "bravery" is really recklessness. And that is absolutely incompatible with cave diving, as it is with racing automobiles, fast and light alpine climbing, and other activities where training and judgment keep you alive. But as this is not a Hollywood movie…

It seems to me that the "Hollywood bravery" you nicely describe really is bravery - Oxford Dictionaries says the word comes from French braverie or Italian braveria (boldness), based on Latin barbarus (c.f. barbarous). Alternatively it may be from bravo (wild, savage). Courage on the other hand comes from Old French corage , from Latin cor (heart). I think based on this the divers are courageous, not brave.

It's true that the word comes from those roots, but the Oxford dictionary you cite says plainly that the definition of the word as it is used today is:

  > Courageous behaviour or character.
https://en.oxforddictionaries.com/definition/bravery

Just as long as we all agree that cave diving is not about being that ridiculous Hollywood stereotype dude who deliberately breaks all the rules for no damn reason and it works out because he broke all the rules for no damn reason.

Re: British divers make contact with missing Thai football team

#67

Post by bradstewart »

hvidgaard wrote: post #36
jaggederest wrote: post #14

Earlier quoted context omitted.

It's interesting, I wonder what the pros and cons are for drilling to retrieve them or send supplies. In the mine collapse situations that I'm aware of, there was already infrastructure on hand for heavy equipment and drilling. I have to imagine that the dangers of cave diving are multiplicative - you don't get enough skill-based improvement from any given trip into/out to make repeated trips a safe option.

I'm sure I don't understand the scale of this. I would however think that you can bring huge industrial pumps and do some plumbing to a suitable place to dump the water and turn them on. Holland once send 7 million ton a day of pumping capacity to England to help them out. Could that not make a serious impact on the water levels in the cave?

Industrial scale pumps certainly exist, but they aren't exactly small and easily portable. I'm not familiar with the one Holland sent England, but I suspect it was pre-assembled on a ship?

The highest capacity pumps in New Orleans can move roughly 10,000 gallons a second, but they require a supply "hose" that's ~8-10 feet in diameter to reach that volume. You'd need to get an enormous hose to a low point of the cave system, which may not be near the entrance.

Then there's the question of what to do with the water you pump out. Maybe there's a river nearby that can absorb it?

It is doable, but it's neither simple, not particularly quick.

Re: British divers make contact with missing Thai football team

#68

Post by azernik »

chiasmic wrote: post #46
jdietrich wrote: post #39

Earlier quoted context omitted.

>How does cave oxygen supply work? Would they not run out of oxygen by the time they can get out? Most cave systems are relatively permeable. Even if you can't see a route out, there are likely to be paths for air movement. The immediate threat is the accumulation of carbon dioxide rather than a deficit of oxygen. Fresh air is about 0.04% CO2, but most caves have ambient CO2 levels of over 1% and some as high as 6%.…

Even if the cave was closed from a gaseous perspective, there is flowing water. Gases dissolve in water, although not necessarily very quickly. Would the flow of water allow for CO2 to be removed from the space given a sufficiently large surface area?

Generally caves have elevated CO2 levels not because of human respiration, but because of outgassing - they're generally eroded out of carbonate minerals, and so the water flowing in carries CO2 inside at higher concentrations than the outside world. The smaller the subsystem the human is isolated in, the faster they perturb that equilibrium toward an even higher CO2 level.

The ESA, of all groups, has a pretty good write-up on this: http://blogs.esa.int/caves/2014/11/19/the-science-of-caves-e... They use cave exploration for astronaut team-building, process/workflow training, and acculturation.

Re: British divers make contact with missing Thai football team

#69

Post by cm2187 »

A_Person wrote: post #62
draugadrotten wrote: post #38

Earlier quoted context omitted.

As an experienced cave diver, I agree with Mr Whitehouse that bringing them out as "packages" should be considered an option. It would be easier than allowing them to swim by themselves in murky waters with no vision. The diving training spoken of might be getting the boys to be used to being towed under water while being packaged up, rather than about teaching them about buoyancy control like adult divers.

You can't be serious. Taking 13 people, with an absolute maximum of Open Water level training (if that), back out through hundreds (or thousands?) of meters of low or zero visibility diving, including (apparently) tight restrictions, without risking the lives of all concerned? Aint gonna happen - unless the water level drops to the point where they can just float back out.

What I don't understand is that surely there must be a wide enough passage for them to have got in in the first place. It may be flooded but if one can walk into them vertically, surely they should be fairly accessible to a diver horizontally. Can't they just follow / be attached to a string or something like that?

Re: British divers make contact with missing Thai football team

#70

Post by sametmax »

isostatic wrote: post #7
saagarjha wrote: post #2

I'm pleasantly surprised to see that they've been able to survive this long without access to food and possibly clean water. I can't imagine what it would feel like to be stuck in a cave for nine days and then suddenly see two divers show up as part of the rescue effort!

> rescuers have said they may have to wait several weeks for the water to subside before they can be taken out. Ouch > Trying to take non-divers through a cave is one of the most dangerous situations possible, even if the dives are relatively easy. That also begets the question: if the dives are difficult then supply will be difficult, but the risk of trying to dive them out is also exponentially greater

The first dive is the hardest. You can install a line during it, which you will use for subsequent dives that will secure you next attempts.
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