Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Titanic tourist submersible goes missing with search under way

bbc.com

Post reply on HN
Print view View original

371–380 of 649 posts

Re: Titanic tourist submersible goes missing with search under way

#371

Post by Xen9 »

MagicMoonlight wrote: post #162
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…

If your design breaks at less than the target then you really have to question the logic of continuing with that design. Making it slightly bigger won't fix the inherent issue with the materials. They're potentially opening themselves up to charges for killing these people. They knowingly or recklessly put them on a boat when it isn't capable of reaching the depth safely and now they are dead.

The CEO was in the vessel and probably would not have put his skin in the game if he didn't believe the vessel was safe.

Re: Titanic tourist submersible goes missing with search under way

#372

Post by Retric »

jhugo wrote: post #365
gymbeaux wrote: post #325

Earlier quoted context omitted.

I’m getting Virgin Galactic vibes. They’ve cut a lot of corners over there and they’re starting commercial flights this summer despite not having I’m convinced the most-safe aircraft. They’re out of money and they’re out of time. That’s what it always seems to come down to, not so much “time vs money” but “safety vs money”.

It's always safety vs. money. A risk-free submersible or spacecraft does not exist. It's always possible to spend more money to further reduce the risks, but naturally with diminishing returns. At some point, you have to decide to accept (very small) risks in order to avoid (very large) additional costs.

People are perfectly happy to accept some risk. However you can’t expect normal people to take on extreme risk and expect a profitable long term business.

If the actual risk are close to BASE jumping then you’ve failed.

Re: Titanic tourist submersible goes missing with search under way

#373

Post by bell-cot »

noirbot wrote: post #263
bell-cot wrote: post #196

Earlier quoted context omitted.

True about recreational divers. I'm trying to explain the sentiments which user paganel originally voiced - which I suspect are kinda common. My sense is that the strong negative feeling are tied to how much of a "just too many emotional points against it" corner case this is. A famous & famously tragic shipwreck, the dangers inherent in their extreme tourism, how very few people can imagine "it coulda been someone l…

I think some of the pushback that I feel to that is that it seems like a socially acceptable guise for just wanting to hate rich people. I'm fine if your opinion is "screw rich people who spend this much on weird things", or even "Rich people who died doing something this frivolous deserved it." But just own that . If this had been the original diving expedition to the Titanic to find the wreck for the first time, or…

> I think some...socially acceptable guise for just wanting to hate rich people.

Yes, some. But my feel is that if a similar number of even-richer people had (say) died in the crash of a luxury helicopter ferrying them to Everest Base Camp, then the negative reaction would have been far less notable.

Re: Titanic tourist submersible goes missing with search under way

#374

Post by myself248 »

aaron695 wrote: post #156
wnevets wrote: post #145

Earlier quoted context omitted.

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

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.

Re: Titanic tourist submersible goes missing with search under way

#375

Post by WalterBright »

kortex wrote: post #47
scarnz wrote: post #30

This appears to be the vessel in question: https://oceangate.com/our-subs/titan-submersible.html Pressure hull made from titanium and carbon fiber, capable of diving to 4000m (13,000 ft). I recall that one reason SpaceX switched from carbon fiber to stainless steel pressure vessels (fuel tanks) was the difficulty of detecting structural flaws. Can any engineers comment on whether that task is easier for a vessel expo…

I'm not really an engineer (general hobbyist, former chemist) but I have built and worked with pressure and vacuum vessels. Positive pressure (tank vs exterior) is much easier to deal with than negative pressure (vacuum vessel at 1 atm, or bathyscape with 1 atm inside and high pressure exterior). In positive pressure, your stress is mostly in the hoop mode, which is stable. This is why aluminum cans can be so thin. I…

In college, a popular showoff trick was to set an empty beer can on the floor. Then balance on it with one foot. If your balance was good and well centered, the can would not collapse. Then, for extra credit, slowly reach down and just tap the side of the can with a finger tip. The can would instantly crush to a disk. Extra karma points for crushing it into a perfect circle, rather than an oval.

It would collapse so fast it was nigh imperceptible.

Re: Titanic tourist submersible goes missing with search under way

#377

Post by jhugo »

Retric wrote: post #372
jhugo wrote: post #365

Earlier quoted context omitted.

It's always safety vs. money. A risk-free submersible or spacecraft does not exist. It's always possible to spend more money to further reduce the risks, but naturally with diminishing returns. At some point, you have to decide to accept (very small) risks in order to avoid (very large) additional costs.

People are perfectly happy to accept some risk. However you can’t expect normal people to take on extreme risk and expect a profitable long term business. If the actual risk are close to BASE jumping then you’ve failed.

> If the actual risk are close to BASE jumping then you’ve failed.

The myriad BASE jumping businesses would probably like a word. Risk tolerance varies.

Re: Titanic tourist submersible goes missing with search under way

#378

Post by koolba »

boppo1 wrote: post #370
carbine wrote: post #345

Earlier quoted context omitted.

According to David Pogue (journo who did a dive on this vessel last year), at least as of last year there was no beacon to transmit location. One would hope radio would be working, in that case. Source: https://twitter.com/Pogue/status/1670826522138091521?s=20

>sealed from the outside >no location beacon Wtf is anyone thinking getting in this thing?

The set of people that would enter an experimental sub to visit the titanic, and the ones that would do it with a craft that is bolted shut from the outside, is probably close to even.

Re: Titanic tourist submersible goes missing with search under way

#379

Post by AustinDev »

rsaxvc wrote: post #232
lb1lf wrote: post #119

Earlier quoted context omitted.

If the sub was designed like a few other deep-sea craft I've looked at, they'd have positive buoyancy and weights to overcome this; the idea being that having to blow ballast tanks at 400 bar pressure differential is rather inconvenient and failure prone. Instead, the weights (attached with electromagnets) are simply jettisoned when it is time to recover to the surface and off you go. The upside to such a simple syst…

Yes, that sounds a lot better. From: https://www.forbes.com/sites/katherinehamilton/2023/06/19/he... "Pogue also shows the vessel uses construction pipes as ballast." I'm having trouble finding the interview video, but dropping ballast involves the crew and passengers rocking the vessel to drop the pipes off the side.

Interesting. If they were resting on the bottom. Could you even rock hard enough to drop the ballasts? Although even if they can get to the surface if they have now power how the hell do you find them? It's not like they'll be float on the surface they'd likely be just below the surface.

Re: Titanic tourist submersible goes missing with search under way

#380

Post by Mistletoe »

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…

The article says even if it floats to the surface they can’t get out. :(

It’s bolted from the outside.

Post reply on HN