Portable sonar systems with in-helmet displays were put in use by the US Navy only last year: https://www.navalnews.com/naval-news/2021/03/us-navy-teams-w...
> A full spacesuit-like helmet with air to be able to talk via radio?
Would fuck up your buoyancy, but there are systems where you have only an air pockt around your mouth. But the range would be so low as to be nearly useless inside a cave.
> Laying down some flexible tunnels that could be inflated with air or maybe just pumped with clear water to gain visibility?
Even assuming that you had those already available, laying them would be a very slow process, and they would be a hindrance rather than help in very narrow passages.
The point would be to use them so that there is no necessity to go through narrow passage. The diver says that when boys went in, they walked through wide openings on bottom.
But, they were probably impractical for other reasons.
Clearly not. Why does someone always have to assume they know better?
> they chose the most difficult transport
What are you even basing this statement on?
> What are you even basing this statement on?
As I understand it, the transport was immensely difficult. The divers and the rescued kids were at great danger. It is unbelievable to me they managed to save them without any special solution.
I'm sorry if my comment was misunderstood.
>Later, after the water had run off, you could see that down at the bottom, where the boys walked in, there were much larger gaps. But the divers couldn’t attach anything to the muddy bottom when laying out the guide lines. They had to follow along the ceiling. The only path they found was through the narrow passageways.
As I understand it, they had to use the narrow passages at the top because they were not able to discover the wide gaps near the bottom. I assume some equipment could help with that making the transport easier once a more comfortable path was found.
Or maybe your assumptions are wrong.
Those "helmets" exist, but helmets as such are used in commercial diving with a tether to the diver. Not very practical to have it running along the cave for multiple divers. The full face masks that allow that are mainly used in open circuit diving and are bulky. I don't know if the pros/cons would make a huge difference.
At one point I believe Tesla or just Musk were planning and developing a pod to carry each boy, but the tunnels and sumps were so narrow that they wouldn't be able to make the turns.
Having tunnels with compressed air to inflate them would have similar issues with the bends. Not to mention the amount of gas and pressure needed to displace all that water.
I guess they took the most direct and logistically available option. I'm sure it will be a case study for the future.
> There was even a discussion about leaving the 12 kids and the football coach inside the cave for the whole rainy season and providing them with food and supplies from outside for months.
I suppose building the equipment for few weeks is better than waiting for months to end of rainy season.
I'm not even sure what you're envisioning but something lightweight and not bulky that is capable of producing sonar images similar to whatever the detectors were in Aliens doesn't exist. And it was zero viz and in completely zero viz you can barely see your hand in front of your mask, assuming you have illumination.
> A full spacesuit-like helmet with air to be able to talk via radio?
That creates a dead space that fills up with CO2, you'd need to actively pump that out through the rebreather which now creates more things to bash into rock and fail and kill you, plus generates more bulk which is the last thing you want into those tight caves.
You can use a full face mask (FFM) that has comms with a rebreather but in a single file cave there's no point and cave divers know how to communicate in single file in zero viz by touch contact. And there's not much to communicate since either you're moving or you're temporarily stuck and the person behind you can't really help you much. With a rebreather you can also talk pretty well in water if you're just close enough to each other. I've also managed to communicate effectively by talking into a normal scuba regulator as well, without having to write anything down.
> Laying down some flexible tunnels that could be inflated with air or maybe just pumped with clear water to gain visibility?
That would probably take weeks and you'd be fighting the pressure of the incoming water inside of the cave. Air probably wouldn't work at all, you'd need to build a pressure differential airlock so that's likely impossibly complicated. Water might work if you built a reservoir at a higher altitude to gain pressure, but them you need to pump the water up there and you need flexible inflatable tubing that can hold a couple atmospheres of pressure and is large enough for a human, and I think I'd prefer to be surrounded by rock rather than by saran wrap that could fail and I'd get entangled it in the shredded plastic and drown. No thanks. As evidenced by the successful recovery, zero viz can be dealt with.
> So many ideas come to mind, but they chose the most difficult transport of sedated and tied up kids ever. I assume they had a good reason, but still do not understand it.
They're all trained at more or less doing that, they've been through the environment, and they've all been through rescue training to drag an unconscious buddy out of the cave. Strapping the kids down, giving them sedatives and putting a FFM on them solved all the problems of taking someone out of the cave that wasn't trained in diving at all. It gives you the smallest package to drag out of the cave along with giving you access to the kids. The coffin that Musk was proposing was more or less just that. By trying to keep the kids dry, now you have CO2 problems, you need a scrubber in the coffin and you need strong enough walls to deal with the pressure differential, that creates bulk and makes it more difficult to move through the restrictions, and if anything goes wrong the kids suffocate and die and there's no access to them at all.
From the perspective of a trained cave diver the solution that they used was nearly perfect.
My take away from the article is that there could have been many more solutions, some more clever, some involving more gear etc., but they were completely short of time and verified information to come up with other viable plans.
Basically any other plan would have needed more checks, preparation, waiting for the gear to be ready, rehearsal, etc. And as said in the beginning of the interview, they feared the kids would be dead any day. As I get it, that’s also why civilians where chosen instead of the pro rescue team, because they were the only one with appropriate gear and experience at that moment in that place.
As I understood there was mud layer that prevented the divers to navigate near the bottom (no way to tie a string as to anchor point to not get lost in zero visibility, no way to feel where the bottom is, etc.). But not so much mud that only the narrow passage was left.
> And as said in the beginning of the interview, they feared the kids would be dead any day
They would be dead if they did not find them on the last day, as it was considered to stop the search. Once the kids were found and supplied with food they had enough time to plan, prepare, rehease, re-check and execute the rescue.
Would not a sonar help? A full spacesuit-like helmet with air to be able to talk via radio? Laying down some flexible tunnels that could be inflated with air or maybe just pumped with clear water to gain visibility? So many ideas come to mind, but they chose the most difficult transport of sedated and tied up kids ever. I assume they had a good reason, but still do not understand it.