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Titanic tourist submersible goes missing with search under way

bbc.com

471–480 of 649 posts

Re: Titanic tourist submersible goes missing with search under way

#471

Earlier quoted context omitted.

And then JJ Abrams put Enterprise underwater, ostensibly to hide it from a stone age civilization. Such a hack. Ruined both of the biggest and beloved scifi franchisee. smh

I still have problems with Voyager and Enterprise landing at all. Besides the maxim that everything is airdroppable at least once.

Voyager I’ll allow since it’s small and pointy, and came with landing gears. The Enterprise is too big. You only get to “hot drop” that saucer section once. (Galaxy class only. Any other saucer sep is apocryphal.)

I hate that Rogue One had Star Destroyers hovering in atmosphere. That’s just dumb, and destroyed the lore about Victory versus Imperial class Star Destroyers.

Re: Titanic tourist submersible goes missing with search under way

#472
post #430

Earlier quoted context omitted.

All the dead frozen bodies on Mount Everest are a testimony to risk hand-waving. But I short-circuit trying to figure which is more stupid, visiting Everest or Titanic. People want an "adventure" and to learn useful things about themselves? Okay train to run a marathon. Now train to run it faster.

Yeah, I just don't get how "sitting in a 5 foot diameter tube for 24 hours looking through a tiny window" is exploring. You didn't make the project happen in any meaningful way - you're just a passenger. Seems like a pretty terrible way to pass the time, even when everything works as expected. I can kind of see the appeal of Everest from a mountain climbing point of view, but I think I'd go and do one of the peaks wi…

Interestingly, it's much easier to climb Everest than K2 (second highest peak). Death rate is one per four who reach the summit (91 deaths total).

Re: Titanic tourist submersible goes missing with search under way

#473

I'm surprised the craft doesn't have a pinger, like airplane black boxes do (and those can survive on the ocean floor, too). 96 hours of oxygen won't help if it takes 200 hours just to find where they are.

They can survive on the ocean floor but definitely not ping from there.

Re: Titanic tourist submersible goes missing with search under way

#474

Earlier quoted context omitted.

Is there some sort of underwater "GPS" tracker they can use to track the sub?

Communicating with submarines is actually a nightmare. The saltwater ruins most radio communications, so you have no chance to receive GPS signals, which are pretty weak even on the surface. One thing the military does/did to communicate with subs is use low-bandwidth text-only very low frequency radio, but you need colossal transmitters and there's no way the mother ship carries one. Hydrophones are also an option,…

There's at least one commercial acoustic underwater modem provider - Subnero out of Singapore. They claim up to 5km range:

https://subnero.com/products/modem.html

Re: Titanic tourist submersible goes missing with search under way

#475

Earlier quoted context omitted.

Is there some sort of underwater "GPS" tracker they can use to track the sub?

Because there is active search and rescue happening, a much lower tech solution is to use dye. But even that presumes a canister on the outside that can be activated from the inside and which will survive the depths of the dive. In retrospect perhaps something that does that automatically if not disarmed after a certain amount of time.

Dye would be as incompressible as seawater. I think a dye container on the outside of the sub could literally be a plastic bag and it would survive.

Re: Titanic tourist submersible goes missing with search under way

#476

Earlier quoted context omitted.

> drive it with a Logitech USB gamepad As opposed to the professionals who went with a microsoft xbox controller? [1] > Or the fact that they scrubbed a Titanic launch for the media due to weather Yes? Weather is a thing. This is not a ride at disney land, of course they cancel the operation when the circumstances are not favorable. In fact doing the opposite would be foolish. The company in question might be full of…

> As opposed to the professionals who went with a microsoft xbox controller? I think what's more telling is that they didn't even splurge on the actual Microsoft Xbox controller. They cheaped out with an unproven logitech gamepad. When you're already doing something in an unorthodox way at least don't half-ass it. > The company in question might be full of jokers, but your points don’t quite illistrate this well. The…

> Your distinction is a bit arbitrary. Every point about this company will always be about appearances unless you have first-hand accounts or experiences.

Not really. Here is a substance based argument: there is no underwater FAA. This company, and any other private submarine company is setting their own quality level and then marking their own homework to see if they have met it. In a commercial environment they are incentivised to cut corners and there is no external force resisting this.

Then you can ask them about their tech and procedures. Do they have redundant means of communication? Do they have multiply redundant means to release the ballast? How many hull penetrations there are and how are they implemented? If they are unwilling to discuss these questions that is worse than a bad answer.

Some comments are criticising their choice of carbon fiber for the middle section of their pressure vessel. I don’t know enough about the engineering there to decide for myself if that criticism is fair or not but that is an argument about substance not appearance.

Re: Titanic tourist submersible goes missing with search under way

#477

let me be naive : carbon fiber composite is about tensile stength, not compression strength ? what happens in the ocean ? compression...

Individual fibres, yes. But the composite material is fibres and resin. Plus the vessel is surely pressurized.

Re: Titanic tourist submersible goes missing with search under way

#478
post #235

Earlier quoted context omitted.

Seems like a pretty stupid design if you ask me

It's traditional in deep submersibles design, dating back to bathysphere. You probably weren't hanging around when they were designing them

Do passengers also need to undergo decompression before exiting the craft?

Re: Titanic tourist submersible goes missing with search under way

#479
post #185

Earlier quoted context omitted.

I'm no expert, but I do know there's anything fundamentally flawed about polymer composites (including carbon fibre composites) in place of metals. Composite properties can be fairly accurately measured and tested, just like any other material including plate steel or aluminium. If a structural failure has occurred, it's related to a design, manufacture or maintenance issue. For example, not enough layers, or a weakn…

> Composite properties can be fairly accurately measured and tested, just like any other material including plate steel or aluminium Metals are uniform and broadly predictable. Composites vary cure to cure. We simply don’t have the deep engineering tables that let you know how a material will behave without destructive testing.

Didn't it take us thousands of years of working with metals (Bronze Age through Modern) to get them to the uniform quality we see today (at least speaking on a commoditized basis)?

I'm sure the story around composites will improve in due time.

Re: Titanic tourist submersible goes missing with search under way

#480

Earlier quoted context omitted.

It gets boring hearing people who can't program or manage blurt out 'move fast and break things' whenever they hear of failure. Learn to code. Or if you're not smart enough learn project management. Alternatively stop using sayings in other peoples fields. Do something dumb like journalism.

I think it's tiring when an industry that has no physical things to break, adopts a saying that flippantly implies that other industries are slow simply because they're not irresponsible enough. I've had quite enough broken things, thank you very much.

Heck, I've suffered enough broken software
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