Wikipedia:Reference desk/Archives/Miscellaneous/2018 July 7

= July 7 =

Thai cave rescue
They are apparently going to try to train the kids in the cave to use diving gear to swim out of the cave soon enough to beat the incoming rainstorms. Supposedly one of the bigger worries is that visibility in silty water is poor, and there's a big danger of disorientation, especially when the diver is inexperienced.

I also read someplace else that they were installing fixed ropes through the whole passage through the cave (like climbing ropes I presume). If they do that, why is orientation such a big problem? Can't you just keep pulling yourself along the rope, even when visibility is zero? You could get banged up or scratched in narrow passages, but protective clothing can help with that. Also there's contraptions like this that pull you through the water: can they use those? I looked at some specs online and there are models with 14.25" max diameter, so they should(?) fit through most any passage a human can fit through. And do magnetic compasses work in caves?  That could help with orientation too.  An electronic one could give an audio or vibration alert to indicate the direction, so again no visibility needed.

Just wondering. I obviously can't do anything about the situation. Thanks. 173.228.123.166 (talk) 06:19, 7 July 2018 (UTC)


 * I suspect they will use a combination of ideas like yours, but there are some challenges, such as the fact that none of the kids can swim. And it's a really long way, around 3 kilometres. This article is a good one - https://www.theguardian.com/world/2018/jul/03/rescue-of-boys-trapped-in-thai-cave-could-take-months-military-warns HiLo48 (talk) 08:00, 7 July 2018 (UTC)


 * According to a TV report I saw about 4 hours ago, they are worried about flooding and CO2 and they are going to try to get them out in the next couple days. The idea of bringing supplies and sitting for months doesn't sound workable.  I'm not following the story closely though. 173.228.123.166 (talk) 08:15, 7 July 2018 (UTC)


 * The rescue attempt is now in progress, in fact. --76.69.47.228 (talk) 05:11, 8 July 2018 (UTC)
 * One of the problems is negotiating several constrictions ("squeezes"), one reportedly 15 inches (37.5 cm) wide. This will necessitate removal of each diver's air tanks and replacement afterwards; not something an untrained person can do, especially without visibility. The method which has been adopted now is for each boy to be escorted by two divers, but I imagine that there must have been some training given too.   Alansplodge (talk) 19:18, 8 July 2018 (UTC)


 * List of diving hazards and precautions should be of interest. You've already mentioned many of the relevant hazards.  Perusing the list I see: overhead environment, low visibility, silt, sharp edges, entrapment hazards, and loss of mask.  It's not clear whether "strong currents or surge" are required to dislodge equipment.  There is also a whole section each on Diver behavior and competence, and Pre-existing conditions.  Cave diving and the sections on Hazards and Safety may also be of interest, as well as Technical diving.--Wikimedes (talk) 20:26, 7 July 2018 (UTC)
 * This BBC report has a graphic (about halfway down) showing the actual method used. The lead diver carries the boy's air who is "held close to diver". In the constricted sections, the boy is pulled through by the lead diver, while the second follows behind. Alansplodge (talk) 09:16, 10 July 2018 (UTC)
 * As time goes by, more detailed descriptions emerge. NB some are contradictory: the Thai government says the boys were given light anti-anxiety medication, whereas several witnesses said the boys were semi-sedated.
 * Each boy was given a full-face air mask to ensure they could breathe, and clipped to a diver. Another diver accompanied them. A cylinder was strapped to the front of each child, while a handle was attached to their backs - and they were held face down to ensure water would run away from their faces. John, the British rescue diver, likened the equipment to "a shopping bag" that allowed them to manoeuvre the boys around obstacles.
 * From The full story of Thailand’s extraordinary cave rescue, a BBC story today. Carbon Caryatid (talk) 18:16, 14 July 2018 (UTC)

How come ExxonMobil has so few employees?
ExxonMobil has revenue of $237 billion and 69,000 employees. In comparison, Eurasian Resources Group, a private mining group, has about 80,000 employees and around $4 billion in revenue. Muzzleflash (talk) 09:27, 7 July 2018 (UTC)


 * Why would you compare companies from two different industries and expect them to be similar? BP has revenue of $240 billion and 74,000 employees. That seems awfully close to Exxon's numbers. Matt Deres (talk) 13:30, 7 July 2018 (UTC)


 * Then to modify the question: Why do the largest non-state owned companies in the largest type of resource extraction (oil and gas) have so many fewer employees than the largest non-stated owned companies in the 2nd largest type of resource extraction (mining)? Muzzleflash (talk) 10:16, 8 July 2018 (UTC)
 * I just checked Rio Tinto Group, the largest mining company, and it has 50,000 employees. So maybe the question is why does ERG have so many employees. Muzzleflash (talk) 10:18, 8 July 2018 (UTC)
 * You really don't understand why drilling a hole and pumping out the fluid needs fewer workers than digging up or digging into the ground? The volume of oil to be extracted might be the same as the volume of ore to be extracted but you have to move a lot less of the extraneous matter to get the oil. --Khajidha (talk) 14:20, 9 July 2018 (UTC)


 * I don't know the answer to that question. Just as a thought experiment, consider how convoluted the path from "stuff in the ground" to "workable material suitable for sale to manufacturers" is and the logistics involved in moving very heavy stuff from place to place. It's possible that ERG has decided to do more of this "in-house" while RTG has farmed it out to third-party groups. It seems likely that the decision to do one or the other would vary a lot with circumstances, including geographic location, placement of refinement facilities, and a bunch of other stuff. If I had a gold mine in Canada and you had one in the third world somewhere, it would obviously make sense for me to invest heavily in automation due to minimum wage and other costs of workers, while you might elect to essentially have a swarm of many hands because the labour is cheaper (and, cynically speaking, expendable). Matt Deres (talk) 14:28, 9 July 2018 (UTC)


 * $4B revenue / 80000 employees comes to only $50000 revenue / employee. Given that ERG presumably has significant non-employee expenses (e.g. energy, equipment), this would suggest that the average employee is not very well paid by Western standards, though I suppose their income might be okay by the standards of the countries where ERG mostly operates.  Dragons flight (talk) 19:20, 8 July 2018 (UTC)