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Titanic tourist submersible goes missing with search under way

bbc.com

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Re: Titanic tourist submersible goes missing with search under way

#141

Post by mcpackieh »

bell-cot wrote: post #89
noirbot wrote: post #63

Earlier quoted context omitted.

Isn't visiting places filled with dead and decomposing people a fairly normal tourist activity? Various catacombs, graveyards, temples, battlefields, memorials, Pompeii... I've got no real thoughts on the "stupidity" of doing this, but visiting the wreck of a famous ship doesn't seem an obviously unsympathetic thing to do compared to visiting the ruins of a city.

Yes...but those are places where where the dead received "proper" burials. (Excepting Pompeii, and maybe some battlefields. Pompeii tends to get a pass because "ancient", "technically buried", and "A-listed Roman cultural site".) And generally, visiting ~none of those other places is a brag-worthy way to show off being one of the modern 0.1%. (Which, these days, gets very little sympathy in many quarters. Even withou…

It's very common for recreational divers to visit ships with bodies still in them. Maybe it's morbid, but it's common and generally you don't need to be "0.1%" to do it. If this story were about some working class people who died while scuba diving around a wreck in shallow water, would you still be trying to vilify them for it?

Re: Titanic tourist submersible goes missing with search under way

#142

Post by WalterBright »

svnt wrote: post #124
svnt wrote: post #121

Earlier quoted context omitted.

@2:40 reading contract: “[…] an experimental submersible vessel that has not been approved or certified by any regulatory body and could result in physical injury, disability, emotional trauma, or death. Where do I sign?”

Oh it keeps going at 3:30: [CEO gestures at interior lighting] “I got these from… Camper World.” “We run the whole thing from this game controller.” [shows some knockoff controller]

What's the matter with that?

Re: Titanic tourist submersible goes missing with search under way

#143

Post by WalterBright »

londons_explore wrote: post #136
HWR_14 wrote: post #116

Earlier quoted context omitted.

Leaving aside the literal tons of weight a tether would require just to life a single person back to the surface (and the weight of the tether), it also could get pushed around a lot by the current. And, most importantly, once you are down there and want to navigate the wreck it would get in the way.

The weight of the tether doesn't matter when it is in water. You just design it to be neutrally buoyant. Either using mini pressure vessels or tanks of light oil.

Neutral buoyancy varies by depth, because water compresses. You'd have to have a tether with the same density of water and the same compressibility.

Re: Titanic tourist submersible goes missing with search under way

#144

Post by saltcured »

floxy wrote: post #113
stickfigure wrote: post #105

Earlier quoted context omitted.

I would guess weight? From pictures, the launch platform doesn't look like something that could manage a tube fabricated from 5" thick steel.

It seems like the epoxy in this composite structure is sustaining all of the compressive loads. The carbon fiber would seem to be just along for the ride, so to speak, since fibers are only useful in tension. Am I missing something?

Wouldn't this be a bit like reinforced concrete? In practice there are not just pure compressive loads, but flexing and shearing that put some areas under tension, so the embedded reinforcements fight that and help keep the bulk material in the right places.

Also, think of the bill of a toucan or fiberglass surf board. A lot of rigidity comes from the tensile strength of the skin wrapped around an enclosed volume of relatively weak stuff that mostly keeps the skin in the right configuration.

Re: Titanic tourist submersible goes missing with search under way

#145

Post by wnevets »

carbine wrote: post #111

I'm hesitant to speculate but just sharing -- an earlier version of this submersible was scrapped: "OceanGate will take advantage of lessons learned during the construction of its carbon-hulled Titan submersible, which was originally built for Titanic journeys. Rush said tests that were conducted at the Deep Ocean Test Facility in Annapolis, Md., revealed that the Titan’s hull “showed signs of cyclic fatigue.” As a r…

unfortunately this sounds like "move fast and break things" in the worst possible way.

Re: Titanic tourist submersible goes missing with search under way

#146

Post by homieg33 »

wnevets wrote: post #145
carbine wrote: post #111

I'm hesitant to speculate but just sharing -- an earlier version of this submersible was scrapped: "OceanGate will take advantage of lessons learned during the construction of its carbon-hulled Titan submersible, which was originally built for Titanic journeys. Rush said tests that were conducted at the Deep Ocean Test Facility in Annapolis, Md., revealed that the Titan’s hull “showed signs of cyclic fatigue.” As a r…

unfortunately this sounds like "move fast and break things" in the worst possible way.

[flagged]

Re: Titanic tourist submersible goes missing with search under way

#147

Post by londons_explore »

WalterBright wrote: post #143
londons_explore wrote: post #136

Earlier quoted context omitted.

The weight of the tether doesn't matter when it is in water. You just design it to be neutrally buoyant. Either using mini pressure vessels or tanks of light oil.

Neutral buoyancy varies by depth, because water compresses. You'd have to have a tether with the same density of water and the same compressibility.

The compressibility of water is fairly negligible - the density increase is only 1% for every 2 kilometers of depth. And obviously the cable also compresses at depth - probably by a similar percentage,

Re: Titanic tourist submersible goes missing with search under way

#148

Post by yetanotherloser »

jiveturkey wrote: post #56
ralphhughes wrote: post #40

Skimming the website, I assume this submersible is using electromagnetically attached drop-weights so that if anything goes wrong and power is lost, the weights drop off and the submersible floats up to the surface again? And 96 hours of life support sounds good, but unless there is another submersible nearby that can dive down, find them AND attach a line, the number of hours of life support will be irrelevant. Of c…

> mercilessly quickly mercifully quickly?

I think this might be one of very few circumstances that can be said to be both at once, sadly.

Re: Titanic tourist submersible goes missing with search under way

#149

Post by inconceivable »

fullstop wrote: post #137
svnt wrote: post #127

Earlier quoted context omitted.

I found the (wireless, $30) game controller: https://www.amazon.com/Logitech-Wireless-Nano-Receiver-Contr... and this from a review: “Pretty good controller, fits in hand comfortably and is compatible with anything I throw at it in a Debian linux environment. The conductive pads are extremely low quality though as I've had to replace them 3 times in the 2 years Ive been using it. For a Logitech product I expect bette…

Good lord, at least use an Xbox controller. They are supported pretty much everywhere and are very durable. The US Navy uses them because they are durable and because new recruits are already intimately familiar with them.

also microsoft has been supplying the navy for a long time.

Re: Titanic tourist submersible goes missing with search under way

#150

Post by fullstop »

inconceivable wrote: post #149
fullstop wrote: post #137

Earlier quoted context omitted.

Good lord, at least use an Xbox controller. They are supported pretty much everywhere and are very durable. The US Navy uses them because they are durable and because new recruits are already intimately familiar with them.

also microsoft has been supplying the navy for a long time.

Yes, and they once neglected to prevent division by zero: https://www.wired.com/1998/07/sunk-by-windows-nt/
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