[HN Gopher] Titanic tourist sub photos show wreckage being broug...
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Titanic tourist sub photos show wreckage being brought ashore
Author : tartoran
Score : 76 points
Date : 2023-06-28 16:17 UTC (6 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| mrguyorama wrote:
| One thing I've completely missed in all this drama: WHY a carbon
| fiber hull? Carbon fiber is not known for being easy to work
| with, or cheap, or strong in compression, or good for water, so
| WHY would you use it on a submersible as "new" technology?
|
| I must have missed some discussion.
| opwieurposiu wrote:
| If the hull were made out of metal it would be much heavier and
| require a much bigger support ship to launch and recover. This
| would increase overall system costs.
|
| The lower density of carbon also removed the need for syntactic
| foam floats.
|
| The CEO had aircraft experience so he liked carbon fiber.
| etrautmann wrote:
| Also, there's seemingly little benefit to low weight in this
| application?
| lacksconfidence wrote:
| In an interview with Stockton Rush, and sure we should take
| his insights with a grain of salt, he stated that in deep sea
| submersibles it's not about weight, but buoyancy. The carbon
| fiber is significantly more buoyant than titanium, meaning
| they didn't need very special foam and ways to mount it like
| is used in Alvin.
| belorn wrote:
| The official reason given by the company is that carbon fiber
| allowed the submersibles to be positive buoyant. This in turn
| allowed them to use electromagnets to hold onto ballast, and in
| the case of a failure the submersibles would loose its weight
| and go back to the surface. It was also considered cheaper and
| smaller than using steel in combination with syntactic foam to
| achieve the same result.
| suprjami wrote:
| The carbon fibre was apparently cheap second hand because it
| was ex-aviation gear past its service life.
| sdeyerle wrote:
| From what I've been able to find, there were never any actual
| pictures/sonar scans of the debris field released. Does anyone
| know any particular reason to not be releasing that to the
| public?
| basisword wrote:
| What would be the reason _to_ release that to the public?
| TomK32 wrote:
| So the next "adventurers" can learn from the mistakes made,
| have a think about it and stay on dry land or wear seatbelts
| if they insist on a recovery of their bodily remains...
| irrational wrote:
| Morbid curiosity. Like rubberneckers driving by a crash
| scene.
| [deleted]
| vkou wrote:
| Because it would be morbid and inappropriate for tourists to
| gawk at a shipwreck.
| hyperbovine wrote:
| There are literally thousands of people on wreck dives as I
| write this...
| curiousgal wrote:
| There's pictures or even footage of sinking migrant ships all
| over the internet.
| bbg2401 wrote:
| Wouldn't "people smuggling ships" be a more apt term, if we
| are to choosing to make the distinction at all?
| mcculley wrote:
| Which was OceanGate's business model.
| sigstoat wrote:
| to the other commenters: there's a difference between a week
| old wreck still being investigated and one a hundred years
| old.
|
| same way there is a difference between photos of dead bodies
| undergoing forensic investigation, and those undergoing
| archaeological investigation.
| fullstop wrote:
| I wonder how much time has to pass before it is socially
| acceptable to gawk at a shipwreck?
|
| I'm not really joking here, there has to be some sort of
| threshold and I'm not sure how it can be defined.
| jackmott42 wrote:
| because of a false flag conspiracy reason of some sort of
| course. probably aliens involved.
| KineticLensman wrote:
| > probably aliens involved.
|
| Sigh. Shea and Wilson conclusively documented [0] the primacy
| of Leviathan, a direct continuation of the Ugaritic sea
| monster Lotan, one of the servants of the sea god Yammu
| defeated by Hadad in the Baal Cycle.
|
| [0] https://en.wikipedia.org/wiki/The_Illuminatus!_Trilogy
| hguant wrote:
| 1. Generally photos from active investigations aren't released
| until the investigation is completed. These are active records,
| and could potentially become part of civil or criminal
| hearings, so the agencies in charge of them tend to keep them
| close until they've finished the report.
|
| 2. The US Coast Guard is a part of the Department of Homeland
| Security; the sonar and pictures they take could reveal
| capabilities they deem important to US national security (ie
| how good the sonar is, resolution of photos, etc.).
|
| 3. It's generally considered poor taste to post disaster photos
| before the families have had funerals. Naval institutions tend
| to be more tradition focused than other entities.
| mrlonglong wrote:
| When are they going to recover the bodies, does anyone know?
| pprotas wrote:
| Is there anything left to recover?
| 0xffff2 wrote:
| Mythbusters did a test at one point where they exposed a dead
| pig to a mere 9 atmospheres/300 feet of water pressure. The
| result is... not pretty. It's safe to say that no matter what
| happened to the Titan, there are no bodies to recover.
| mrlonglong wrote:
| I've now seen it. OMG.
| dgrin91 wrote:
| There are no bodies left to recover
| badrabbit wrote:
| Unpopular sentiment, but: The comments and memes I've been seeing
| at just about every corner of the internet regarding this
| disaster is downright shameful and disgusting. I don't care if
| they had it coming or they were terrible people. It is
| fundamentally shocking for me to see so many people who I guess
| were just never brought up or taught to have some minimal value
| and sanctity for human life?
|
| I always thought it was sort of a joke when people said "eat the
| rich", especially when they're living in developed countries.
|
| People are the scariest monsters out there.
|
| Celebrating someone's death means you would have killed them
| yourself if there was no consequence, am I wrong in saying that?
|
| It's not like I am rich or have some sort of billionaire-fetish.
| But a human being is a human being right? And it's a horrible
| thing to celebrate a person's death right? Even with bin laden's
| death, I understood celebrating defeat of an enemy but not death
| of someone's child/family.
|
| This stuff combined with sentiment/hatred towards people who are
| politically hostile/disagreeable paints a picture of a bleak
| future for this society.
| hotpotamus wrote:
| I feel like every English speaker has seen or read one of the
| versions of "A Christmas Carol", so you'd think the idea that a
| wealthy miser would be hated by his community would be a fairly
| fundamental idea.
| badrabbit wrote:
| Hate and dislike are different things. Hate means you wish
| harm on them imo. In this case people are not only glad
| someone died, they are joking about more people like them
| dying. And i guarantee the majority are not even joking.
|
| You can disapprove of people's decisions and dislike them for
| it but life is sacred and loss of it is not a cause for
| celebration.
| hotpotamus wrote:
| I don't know where you get the idea that life is sacred,
| but that hasn't been my experience. I also wonder if maybe
| there's a lesson you can take from learning how despised
| these men are in much of the world.
| Ekaros wrote:
| I'm not sure about celebration. But not being particularly
| sympathetic when few ultra-rich die by essentially playing
| russian roulette for entertainment...
|
| There are each day huge number of bigger tragedies. From people
| starving to death or more rarely by being murdered by someone.
| Like for example drone-strikes. Both of those should be
| considered infinitely larger disasters than this.
| thorncorona wrote:
| It's a different type of humor is all.
|
| > Celebrating someone's death means you would have killed them
| yourself if there was no consequence, am I wrong in saying
| that?
|
| The right word is probably contempt. For example, contempt
| towards the rich and corporations for being responsible 1/2 of
| the inflation in the EU, while people are struggling.
| tailspin2019 wrote:
| Totally agree with you. I've found this very surprising too.
| (Perhaps I was naive).
|
| Edit: The {at the time of writing} downvotes of your comment
| kind of further illustrates your point, sadly.
| Blackthorn wrote:
| You should see what the newspapers of the time looked like
| after the Titanic sank. Jokes around rich people dying are a
| classic source of humor in the English language.
|
| Generally the easiest way to be obscenely wealthy and avoid
| having people celebrate your demise is to make your vanity
| projects acts of public good. A few of the billionaires of the
| previous century figured that one out.
| badrabbit wrote:
| Then those people back the sucked too.
|
| Are you familiar with the fable of the fox and the grape?
| That's what these people are like, the bitter fox who hates
| grapes only because it believes it can't have it.
| UniverseHacker wrote:
| Agreed, the amount of hatred and us vs them mentality between
| groups that is forming online is really saddening. Different
| groups have their preferred target- "immigrants," "boomers,"
| "billionaires," etc. to justify dehumanizing people, and
| blaming them for things based on some arbitrary category,
| rather than judging people by their own actions, and having
| empathy for people even if they did something you don't like.
|
| Rush was arrogant, and made some big mistakes, but I don't wish
| death on him or his passengers. I do hope this example will
| serve as a warning for engineers in the future to be less
| arrogant, and more safety conscious.
| soneil wrote:
| I honestly haven't seen much of that on HN at all.
|
| There's really three things that make this a hugely curious
| story. One is that it's relatively unique. The same way that
| car crashes don't make the news but plane crashes do -
| effectively, this is to plane crashes, as plane crashes are to
| car crashes.
|
| Next, it's frankly interesting from an engineering point of
| view. Especially as it doesn't need to be your wheelhouse to
| understand the enormity of 2.7 tons per square inch. It's On
| with an 'n' that's obviously enormous.
|
| And thirdly, the fact that the CEO appears to have ignored the
| experts and YOLO'd it, is hugely vindicating to anyone who
| considers them an expert in their niche. That's the closest
| this gets to schadenfreude for me.
|
| The only thing really interesting about the people inside, is
| that it removed said CEO from the story so he can't answer for
| himself.
| tailspin2019 wrote:
| > I honestly haven't seen much of that on HN at all.
|
| I read the parent comment as more a general commentary on the
| overall internet-wide reaction to this rather than being
| specifically about HN.
|
| I agree with all your points. You summed up why this is
| interesting, relevant to this audience and worthy of analysis
| to see what we can learn from it.
|
| I also agree with the parent that many (online and in media)
| seem to be showing very little respect for the deaths of
| fellow humans, based on arbitrary labels/assessments, when
| most of these "commentators" had never even heard of these
| unfortunate individuals before last week.
|
| > it removed said CEO from the story so he can't answer for
| himself.
|
| Yes this is worth repeating too. We're getting one side of
| the story from what has been rather sensationalist reporting
| all round. It looks on the face of it like he made some
| pretty terrible mistakes, but we don't know all the facts
| yet. I think inquiry is appropriate at this stage, but
| assassination of character before they've even finished
| recovering the debris [0], not so much.
|
| [0] I _would_ have said "buried the dead" but of course the
| families and friends have nothing to bury. If people can't
| feel empathy for the dead, perhaps they could at least spare
| a thought for their families.
| jareklupinski wrote:
| > I honestly haven't seen much of that on HN at all.
|
| dang is an excellent moderator :)
| gjulianm wrote:
| It's not as much as "celebrating someone's death" (you can't
| really celebrate the death of someone you didn't know even
| existed) as much as pointing out the idiocy of paying 250k
| dollars to see the Titanic in what can be only described as a
| MacGyvered cylinder of death, ignoring regulations, advice from
| experts, and even basic engineering. People being killed by
| their own hubris has usually been a source of comedy.
|
| > This stuff combined with sentiment/hatred towards people who
| are politically hostile/disagreeable paints a picture of a
| bleak future for this society.
|
| Well, something that might add context for you is that a lot of
| people already think the future for society is very, very
| bleak; and they think that the ones to blame are just like the
| ones in the submarine, specially the CEO. So it's no wonder
| there's not much empathy going around for them.
| badrabbit wrote:
| > It's not as much as "celebrating someone's death" (you
| can't really celebrate the death of someone you didn't know
| even existed...
|
| I have seen many posts wishing elon and zuckergerg would also
| make a similar trip in this same context, not just
| celebrating but begging for more bloodshed.
|
| > Well, something that might add context for you is that a
| lot of people already think the future for society is very,
| very bleak; and they think that the ones to blame are just
| like the ones in the submarine, specially the CEO. So it's no
| wonder there's not much empathy going around for them.
|
| B.s.! Everyone making such posts is living in the best time
| to be alive in human history and most of them in developed
| countries which at a global scales makes them the filthy rich
| people! To me these are all spoilied rich brats with iphones
| whining about billionaires because they hate their shitty
| lives. In a way they earn their misery by showing their true
| hateful and pessimistic nature. Their parents voted badly and
| they vote badly and then blame anyone but themselves in this
| democracy. Can't even blame billionaires controlling the
| media because everyone has a smartphone now. They all stay in
| their bubbles and hate each other and everyone outside that
| bubble and blame anyone but themselves.
| Blackthorn wrote:
| > Their parents voted badly and they vote badly and then
| blame anyone but themselves in this democracy.
|
| Careful you don't break your arm with all that reaching
| you're doing.
| gjulianm wrote:
| > Their parents voted badly and they vote badly and then
| blame anyone but themselves in this democracy. Can't even
| blame billionaires controlling the media because everyone
| has a smartphone now. They all stay in their bubbles and
| hate each other and everyone outside that bubble and blame
| anyone but themselves.
|
| That does seem like a very simplistic take. How do you fit
| climate change into that? Or rising inequality? Or opaque
| lobbying? Or, in the US, an electoral system that just
| gives two options to people? Or the housing market going
| bonkers almost everywhere?
| fullstop wrote:
| > Celebrating someone's death means you would have killed them
| yourself if there was no consequence, am I wrong in saying
| that?
|
| Yes, I think that you're wrong -- I do find some of the memes
| amusing, but I'm not celebrating a person's demise. I find
| humor in the absurdity of it all. Most, but not all, of the
| memes that I've seen have been making fun of the sub itself and
| not the passengers. Yes, I find a photo of a ps2 controller
| attached to a propane tank amusing, but that's about the sub
| and not the passengers.
|
| HN is a a bubble, and the people here live in a different world
| than a lot of the rest of the world. On the same page, the
| ultra wealthy live on a different plane entirely. Surely you
| can see how a person struggling to make ends meet might laugh
| at the short-sightedness of a person willing to spend as much
| as they earn in _years_ on a deadly weekend excursion?
| badrabbit wrote:
| > Surely you can see how a person struggling to make ends
| meet might laugh at the short-sightedness of a person willing
| to spend as much as they earn in years on a deadly weekend
| excursion?
|
| No. That is hypocrisy. I guarantee 99% of people if they had
| the same amount of money they would something adveturous.
| Maybe a balloon trip in the alps, a visit to antarctica,
| sailing the pacific whatever. And if an accident befell them
| they wouldn't want people to treat their memory and their
| loved ones who are survived by them this way.
|
| Honestly, I look at shit like this and I absolutley do not
| want to help anyone in need in this society at all except
| maybe children. The people who are not scammers pretending to
| need help are hateful and bitter. Well good luck, you earned
| your position life by hating on others simply because they
| are not helping you because they can.
|
| Don't get me wrong, I get the sentiment that if it was I, I
| would give a lot more and help people but the idea that
| simply because you have lawfully earned money you owe people
| shit? How ridiculous! That is theft! These people want to
| steal money that isn't theirs simply because they are many
| and that person is one and they can take that money that does
| not belong to them. And why exactly should a bunch of theif-
| at-hearts be helped?
|
| I don't hear any starving third world kids demand americans
| "struggling" with obesity owe them food. Even post-colonial
| countries at most demand debt forgiveness not an outright
| transfer of wealth.
| jackmott42 wrote:
| [flagged]
| lamontcg wrote:
| As a cave diver it just pissed me off when people take
| completely unnecessary risks and then after they die we can't
| discuss that they were idiots after the fact. I've read so many
| accident reports of people dying while scuba diving on dives
| that should be easy.
|
| James Cameron has been down on the Titanic 33 times. It can
| absolutely be explored safely over and over by human
| submersibles.
|
| The only reason for this entirely avoidable accident is the
| hubris and overconfidence of the OceanGate CEO.
|
| The fact that it imploded on a dive to a monument to
| engineering hubris is almost like Nature is trying to put a
| period on the end of the sentence here.
|
| And there's a lesson to be learned here about silicon-valley-
| esque "move fast and break all the rules"
| counterintuitive/contrarian decision making. The blog article
| on why Titan isn't Classed is a good example of this kind of
| thinking, which has now been decisively marked-to-market:
|
| https://web.archive.org/web/20230619161930/https://oceangate...
|
| And there's a lesson here about the fact that otherwise smart
| and intelligence people (which he must have been to found the
| company) can be utterly stupid at times, and even over the
| long-term. There's a very common fundamental attribution error
| / correspondence bias / actor-observer asymmetry going on here
| where people cannot decouple someone's traits from their
| actions. You see this as well in some of the recent discussion
| around Prigozhin where people assert that he is not a stupid
| man (okay) therefore it is impossible that the whole
| explanation for the recent coup-attempt-whatever was that he
| got angry and make a dumb mistake--so it must be some kind of
| overly-complicated ruse. Also that buying Twitter could be
| really dumb, and that invading Ukraine could be really dumb.
| Lots of intelligent men being royally stupid in public lately.
| badrabbit wrote:
| I understand if you criticized their decision but saying they
| deserved to die or that it was a good thing or even wishing
| more rich people would have the same fate is what my comment
| is about.
| watwut wrote:
| > Celebrating someone's death means you would have killed them
| yourself if there was no consequence, am I wrong in saying
| that?
|
| No it does not mean that, obviously. In your quest to righteous
| anger you have just wrote nonsense.
| crote wrote:
| I think you're reaching a bit.
|
| I'm not seeing very many people "celebrating their death". I
| _am_ seeing people making fun of the complete absurdity of the
| situation: a couple of billionaires are spending the equivalent
| of two Starbucks coffees to visit a mass grave in an untested
| discount submarine known to have safety issues, fully aware
| that it could mean their death and just... not caring?
|
| When you are a minimum wage worker, seeing people spend
| _several years ' wages_ on something as silly as this, it just
| feels like you are living in a completely different reality. It
| is so _absurd_ that I wouldn 't have believed it if it was
| written in a science-fiction book. It is so detached from
| normal life, it just doesn't feel real.
|
| > I always thought it was sort of a joke when people said "eat
| the rich"
|
| It is both a joke, and not a joke. Some people are _literally_
| starving, and wealth inequality is worse than it was during the
| French Revolution. I don 't know anyone who wants to literally
| "eat the rich", but it is getting increasingly obvious that the
| status quo isn't sustainable either.
|
| > you would have killed them yourself if there was no
| consequence
|
| No, that's not how it works. Very few people _actively_ want
| other humans to die, but that doesn 't mean they will mourn the
| death of every single stranger either.
| mrguyorama wrote:
| >fully aware that it could mean their death and just... not
| caring?
|
| The reality is that these people have ZERO proper
| understanding of risk, because they've never actually been
| allowed to fail in life, so they regularly make stupid
| choices and dumb mistakes that normal people with normal
| experience would not, because many normal people have
| functioning risk management.
|
| Then also remember that "for some reason" these kind of
| people run everything.
| kareemm wrote:
| Curious how this is recovered. So they send down another
| submersible that is able to attach a cable to debris that can be
| pulled up by a winch?
| jtriangle wrote:
| Yes, it's done via ROV's with manipulator arms that attach
| salvage cables to them. Way less failure prone than trying to
| bring them up with the ROV's directly because the ROV's are
| normally tethered via a fairly light duty tether that's
| connected to a base station that raises/lowers the craft. That
| keeps things much more maneuverable because the ROV doesn't
| have to drag around thousands of feet of cable, and, it
| provides some damping from any movement of the host ship
| operating it.
|
| Additionally, the ROV can stay submerged, looking for other
| things to grab, while salvage cables are raised/lowered. Doubly
| important because those sorts of winches run at ~1000ft/hr, and
| the wreck is ~12.5k feet down, so over a full day for one
| recovery.
| lb1lf wrote:
| I have never hauled submersible wrecks from the seabed, but
| have recovered lots of other stuff from the same place.
|
| Depending on the weight and bulk of the component, you'd likely
| do one out of three (at this depth; in shallower waters, you
| have more options)
|
| a) Small-ish items are simply dropped in a basket attached to
| the ROV doing the recovery, then brought back to the surface
| with the ROV.
|
| b) Larger items may be handled by the ROV to a basket suspended
| from a winch, then hoisted to the surface.
|
| c) If the items are too large for the ROV to handle, it will be
| used to attach a sling to the item, which is then in turn
| attached to the hook of a crane/winch, before being hoisted to
| the surface.
| jayrot wrote:
| The Navy also has the FADOSS, though it wasn't needed here I
| believe. It can lift insane amounts, at insane depths.
|
| https://en.wikipedia.org/wiki/Flyaway_Deep_Ocean_Salvage_Sys.
| ..
| lb1lf wrote:
| -This was interesting, thanks!
|
| It appears they utilize a passive system to dampen the
| effect of vessel movement, whereas in many (most?) other
| cases compensation is done actively by the traction unit
| (the twin drums with the rope looped over them in the
| center of the photo) and the storage winch (bottom) being
| wired to an accelerometer installed on the vessel.
|
| I guess the navy uses the passive system as it will be good
| enough and does not require that you spend time figuring
| out the vessel geometry to input the data into the winch
| control system - which is just another source of problems
| when you're in a hurry.
|
| I like this, it seems they've made the kit as simple and
| robust as possible while still fulfilling its intended
| purpose.
| dbancajas wrote:
| and why did they do this? who paid for this recovery?
| lb1lf wrote:
| In the cases I've been involved in, it has largely been oil
| companies or their subcontractors footing the bill,
| occasionally scientists or, uh, treasure hunters. (I work
| for a company making this exact type of recovery gear, so
| every now and then I have to do some field work)
| Wojtkie wrote:
| The first image does show the porthole without any glass
| (acrylic) in it, but I'm sure an implosion would be violent
| enough to blow it out anyway. I'm going to be very interested in
| what they determine to be the critical failure point. Porthole is
| a possibility, but there were some other points of failure in the
| joining of the titanium domes to the carbon composite hull.
| cityofdelusion wrote:
| Videos of the thing being built show a very sloppy epoxy job of
| joining the titanium ring to the carbon fiber hull. There seems
| to be no dust control, no climate control, and no attempt to
| make sure the epoxy is free of voids. I've honestly seen more
| care go into random youtubers making "river tables" than the
| epoxy job that went into this critical structural junction.
| mechhacker wrote:
| I'll speculate that because they are pulling pieces of the Ti
| domes without signs of carbon attached to it that the joint
| there wasn't stiff enough, and that carbon separated during
| failure without plastically deforming the Ti at the joint.
|
| But, that's speculation and I'd need to see more pics with more
| details.
| UniverseHacker wrote:
| I would speculate that all of the carbon basically
| instantaneously liquefied under the pressure after a critical
| threshold of fibers failed, leaving the Ti untouched.
|
| I also want to mention that the large end caps you are seeing
| weren't bonded to the hull at all- there was a small Ti
| flange epoxied to the hull, and then the large domes were
| bolted to that. The front, with the window, was unbolted and
| rebolted every time for ingress/egress.
|
| There is no way that CF epoxied to thick Ti is going to make
| a strong enough bond that it will deform the Ti when it
| detaches. In this case, the geometry of that "glued" joint
| was such that it was forced together by the pressure
| underwater, rather than pulled apart- so it was not necessary
| for it to have any real strength other than for holding the
| end caps on at the surface, and filling voids to make it
| seal.
| mechhacker wrote:
| I see. Thus that large Ti flange that was bonded to the
| dome didn't carry a load through the bolts significant
| enough to deform the dome either. Carbon gone in a flash
| and comes apart at that joint totally, Ti is left hanging
| in water.
| fullstop wrote:
| I was hoping to see if that titanium flange was still
| bolted to the cap, but it's obscured by the tarp in the
| photo.
| UniverseHacker wrote:
| The hull imploded, not the window, but the shockwave probably
| pushed the window outward or shattered it, as it was only held
| strongly against moving inwards.
|
| People make a big deal about the acrylic glass not being rated
| for the depth, but I think it's almost impossible that it was
| the window, and think it must have been the hull:
| * The properties acrylic are well understood, and the strength
| of an acrylic disc is trivial to calculate, even if not "rated"
| you can easily calculate if it's strong enough * The
| window should fail visually with a lot of warning before
| rupture * If the window failed with the titanium end cap,
| there would be no reason for implosion of the carbon fiber hull
|
| The hull on the other hand is an irregular/non-homogenous part
| that is impossible to model accurately. There was no way to
| know how strong it was without extensive testing on a number of
| identical hulls- which they never did. The solidworks modeling
| method they used to give a ~2x margin of safety was nonsense as
| it ignores the realities of stress cycles, defects, etc.
| zaebal wrote:
| Can we assume that if the acrylic was a point of failure,
| then the whole titanium end cap section would appear much
| more damaged, than what we can see on those pictures?
| timbit42 wrote:
| Doesn't it depend on the type of failure? Apparently it
| didn't break but might have deformed to the point that the
| seal was compromised.
| zaebal wrote:
| Assuming violent implosion.
| postmodest wrote:
| > The window should fail visually with a lot of warning
| before rupture
|
| The window would deform up to 2" during dives, according to
| passengers.
| UniverseHacker wrote:
| That does sound pretty sketchy... but from what I've heard,
| acryrlic should start to fracture in a way that makes it
| opaque before it catastrophically fails.
| wumms wrote:
| The time between opaque and failure might be little at
| that pressure.
|
| Somewhat related (possible material fatigue):
|
| A 16-meter (52-foot) high aquarium has burst at a hotel
| in downtown Berlin (2022): https://www.dw.com/en/berlin-
| massive-aquarium-home-to-1500-f...
|
| Manufacturer:
| https://www.reynoldspolymer.com/projects/aquadom/
| [deleted]
| zardo wrote:
| The monitor mounts screwed directly into the hull seem a
| likely starting point for the failure.
| AlbertoGP wrote:
| > _The monitor mounts screwed directly into the hull seem a
| likely starting point for the failure._
|
| Nothing was screwed directly into the hull:
|
| > These handle-lights aren't attached to the carbon fiber.
| The sub is lined with a big insert, a perforated metal
| sleeve, that fits snugly against the carbon fiber, like a
| rolled-up poster in a mailing tube. "The thing with carbon
| fiber is you can't cut holes in it. It doesn't like that,"
| Rush says. "Nothing touches the carbon fiber."
|
| -- David Pogue in "What I Learned on a Titanic Sub
| Expedition" https://nymag.com/intelligencer/2023/06/what-i-
| learned-on-a-...
| akiselev wrote:
| In the photos I've seen, it was pretty clear that they had
| a separate inner hull for mounting stuff. If they really
| drilled into the outer hull, it wouldn't have survived the
| first trip as that would have certainly caused matrix
| cracking that propagated to the skin. It would have failed
| in the first 1000 meters.
| TechBro8615 wrote:
| How was the window "connected" to the hull? Would that be a
| weak point?
| EA-3167 wrote:
| This sub was a carbon fiber cylinder with two titanium end-
| caps, and the porthole was fitted into the forward end-cap.
| Wojtkie wrote:
| Deep sea portholes are usually cones of acrylic that seat
| right into a port in the hull [0]
|
| [0]https://www.researchgate.net/publication/340442621_Predi
| ctio...
| UniverseHacker wrote:
| They machine a wide ledge on the titanium, so the window is
| pushed into the groove/sill under pressure, basically a
| large window that is covering a smaller hole that it can't
| fit through. For all practical purposes, it justs sits on
| there and the pressure holds it on. It would also have
| bolts and/or sealant to keep it in place when not diving.
| nomilk wrote:
| > The hull on the other hand is ... is impossible to model
| accurately.
|
| Why is the hull difficult to accurately model? (assuming the
| exact materials and precise dimensions were known).
| UniverseHacker wrote:
| We're talking about a bunch of layers of fibers, and woven
| cloth impregnated in epoxy. It's a pretty messy, irregular
| thing with voids, gaps, broken fibers, etc. even if you lay
| it up robotically (as they did).
|
| The modeling they did assumes a perfect material, and then
| adds some arbitrary factor of safety that will hopefully
| account for imperfections. It probably would have been fine
| if only used for one dive, but not after a substantial
| number of fibers had snapped as the hull flexed across
| numerous dives.
| akiselev wrote:
| Carbon fiber can't be inspected like metals can using
| radiographic, liquid penetrant, or magnetic particle
| testing, so even if we did know the exact materials and
| precise dimensions [1], it's very hard to characterize them
| and how they responds to stresses.
|
| [1] _composite_ materials are not as homogeneous as metals
| are, so most of the time we actually don 't know the exact
| materials and precise dimensions. Only manufacturers that
| make enough parts to afford to do destructive testing can
| characterize the process enough to make reliable guarantees
| about part strength.
| sottol wrote:
| There are a variety of non-destructive inspection and
| testing methods for composite, like ultrasonic c-scans
| and pulsed thermography that I know of.
|
| And you can produce reliable composite parts (you don't
| want homogenous, but them to come out exactly as spec'ed)
| under strict control, but it doesn't look like they
| necessarily did that here. They seem to have eg foregone
| autoclave curing of the tube section probably due to
| cost.
| UniverseHacker wrote:
| They could have identified defects with non-destructive
| testing, but they almost certainly would have found a
| huge number of them, and had no way to reliably model the
| importance/potential impact of them.
| causality0 wrote:
| From everything I've read, the entire carbon section of the
| hull could be considered a weak point.
| KineticLensman wrote:
| > the entire carbon section of the hull could be considered a
| weak point
|
| It is possible that the carbon fibre delaminated
| catastrophically, possibly as a result of stresses
| accumulated over multiple descents.
| sumo89 wrote:
| The only way the carbon tube hasn't turned to sea dust is
| if the porthole failed first. When carbon fibre fails it
| catastrophically fails. I'd put money on the joint between
| the ti and carbon being the weak point and once there's a
| chip in the carbon under that much pressure it'll
| disintigrate.
| KineticLensman wrote:
| fair points. Hopefully the investigation will nail the
| actual cause down.
| ortusdux wrote:
| This is my understanding as well. I'm not surprised to see
| that the titanium piece survived unscathed. IIRC, the
| companies goal was to provide more cost-effective trips by
| transitioning from the standard solid titanium hull to a
| Ti/carbon fiber composite. This decision was controversial.
| They fired their head of QC after he strongly opposed the
| change. One key argument he made was that the design
| prevented ultrasonic inspection, which would mean that they
| could not monitor the health of the composite over time.
| ajross wrote:
| To be clear, way too much of what I've read on this subject
| has been excessively confident tut-tutting with little to no
| real engineering expertise.
|
| People want to imagine that the simple use of carbon fiber
| here was the sole mistake, I guess because it's easy to
| understand and makes us feel smart. But come on, engineering
| is harder than that. Carbon fiber pressure vessels have a
| long history. Composite material failure modes are for sure
| more complicated than metals but they certainly aren't a
| mystery. We've been using composites for more than half a
| century, we know how they work.
|
| No, my gut says the root cause here (if we ever find one[1])
| is going to turn out to be a more routine kind of engineering
| fuckup. It'll be just some weak point that the analysis
| failed to turn up.
|
| [1] And sure, if we don't then the "carbon fiber death
| cylinder" theory will just become part of the folk truth, I
| guess.
| beAbU wrote:
| This sub is not a pressure vessle though, is it?
| lb1lf wrote:
| But - sincere question, as I am largely ignorant on such
| matters: Those pressure vessels made from composites
| usually are used to contain a pressure on the inside,
| taking advantage of the excellent tensile strength of the
| carbon fibers, no?
|
| Having to withstand a large, external pressure is a whole
| different cup of tea, isn't it?
|
| (Please be gentle; I am an electronics engineer)
| dragonwriter wrote:
| > People want to imagine that the simple use of carbon
| fiber here was the sole mistake
|
| Some people might characterize it as likely being the
| _decisive_ mistake, but I've yet to hear anyone describe
| that as the _sole_ mistake, there being so many obvious
| failures.
|
| > Carbon fiber pressure vessels have a long history.
|
| But does deliberately playing with the service life of
| carbon fiber for pressure vessels have a long history?
|
| https://www.washingtonpost.com/world/2023/06/23/titanic-
| subm...
|
| This submersible involves a field where there is a lot of
| hard-won experience of how to do things safely, but where
| much of that experience was _overtly_ viewed by the firm as
| "waste".
| mechhacker wrote:
| There are non-trivial differences in designing vessels
| loaded with compression vs. tension, and the most
| experience we have is with internal pressure (e.g.
| tension).
|
| The analysis is very nonlinear and unfortunately not as
| widely understood as internally pressurized vessels. It
| requires a lot more analysis, troubleshooting, and
| expertise that is short in supply.
|
| Add the additional catastrophic failure modes for
| composites and there's a reason that industry experts
| warned against this.
| ajross wrote:
| With respect: that's exactly the kind of glib, drive-by
| analysis I'm talking about. What you're saying simply
| isn't true. People have been testing composites in
| pressure chambers and every load imaginable for decades.
| _Yes_ , clearly they don't act like steel. But saying
| that it's impossible is just too easy.
|
| Just watch. It's going to be a routine design flaw, like
| they added a joint or a wiring hole in a bad place and
| didn't re-run the model.
|
| ( _Edit because this was misunderstood: I 'm not saying
| what the failure is. I'm saying that we DON'T KNOW what
| the failure is, and that given the choice between makes-
| me-feel-smart pontification about materials and a routine
| design flaw in a prototype device, I'm going to bet on
| the routine failure every single time._)
| Johnny555 wrote:
| _Just watch. It 's going to be a routine design flaw,
| like they added a joint or a wiring hole in a bad place
| and didn't re-run the model._
|
| I like how you complain about people making glib drive-by
| analyses (that are at least based on actual submersible
| experts saying they shouldn't have used carbon fiber) by
| making a glib drive-by analysis that's based on pure
| conjecture.
| ajross wrote:
| It was a turn of phrase. I made the same point in a
| neutral, non-prescriptive manner (c.f "My gut says")
| upthread. Taking that sentence out of context is pretty
| poor form, whether you agree with me or not.
| causality0 wrote:
| I'm going to put my trust in the engineer who was
| overridden and fired for calling the thing a death trap
| before it killed five people. The thing was down-rated to
| 3000m and then it was used at 4000m therefore it
| imploded. I'd call that a management flaw more than an
| engineering flaw.
| ajross wrote:
| You're mixing things up. The hull that was downrated
| after inspection was a _different_ submarine. The guy who
| was fired was an executive, not an engineer on the
| project (no idea about his background), and while he
| expressed concerns over safety he did not cite the use of
| carbon fiber as a problem (or at least it hasn 't been
| reported that he did).
|
| Which is all to say: basing your opinions on this stuff
| on easily-consumed, tempting pseudoanalysis clickbait is
| a _terrible_ way to figure out what went wrong. And in
| particular putting your ducks in this carbon fiber
| nonsense instead of "they probably just put a hole in
| the wrong place" seems poorly grounded to me.
| TechBro8615 wrote:
| Here's a video of hydraulic pressing carbon fiber to its
| breaking point: https://youtube.com/watch?v=xWTXeGiM8K8
| mechhacker wrote:
| Worth noting that because he's using a hydraulic press, the
| load isn't constant.
|
| It deforms, fibers break, and thus the load decreases as
| the deflection stays relatively constant in that time
| frame.
|
| With external pressure the load doesn't decrease. Fibers
| break -> deflection increases -> more fibers break. There
| isn't load relief as long as the vessel is still holding
| pressure.
| Pigo wrote:
| It seems likely much more effort will go into evaluating the
| failure than went into designing this submersible. It would be
| interesting to know how much more.
| EA-3167 wrote:
| I'm interested in seeing the skids, and learning about where
| they were found relative to the rest of the debris. Were the
| skids totally mangled, implying that they were attached when
| the implosion occurred? Is the debris field pretty contained,
| or very spread out? The former implies that the sub was close
| to the bottom, the latter implies that whatever happened
| occurred at a depth which allowed for currents and drift to
| spread the debris. If the skids are mostly intact then maybe
| there was some warning of trouble and the people in the sub
| tried to drop ballast. If the skids are destroyed then whatever
| happened is more likely to have been sudden and without
| warning.
| KineticLensman wrote:
| Yes, this technique was critical to understanding the break
| up of the space shuttle Columbia as it re-entered. The debris
| track stretched across Texas and Louisiana, and in general
| objects to the west were those that had broken off first.
| Although things were confused because differences in
| ballistic number affected how far fragments travelled
| eastward, and in some cases modules broke off, travelled east
| and then disintegrated into sub-components.
| x3874 wrote:
| "In email messages seen by the BBC, Mr Rush had previously
| dismissed safety worries from one expert, saying he was "tired of
| industry players who try to use a safety argument to stop
| innovation"."
|
| Definitely Muskian vibes. I'll wait for the day Musk will use his
| own Dragon capsule or Spaceship...
| CommitSyn wrote:
| I'm not sure pushing space exploration back a decade because
| you dislike one human is worth the tradeoff.
| bennylava wrote:
| [flagged]
| michaeljx wrote:
| Dragon has been certified by NASA, which is exactly how new
| innovations should happen. Try a new technology and certify it
| with an independent authority that uses well established
| certification standards
| TechBro8615 wrote:
| While I agree with your general premise, is it fair to call
| NASA an "independent" authority when they're also a SpaceX
| customer? In fact many of NASA's own project timelines depend
| on SpaceX meeting its development milestones, so there could
| be some bias in favor of prematurely approving SpaceX
| projects.
|
| I suppose the FAA would be more of an independent authority
| in that regard, although I'm not sure how much authority they
| have over space regulations (compared to launch).
| dghlsakjg wrote:
| FYI: the FAA certified Dragon for the first ever commercial
| re-entry license in 2010.
|
| https://www.faa.gov/about/office_org/headquarters_offices/a
| s...
| danpalmer wrote:
| A Musk vibe on a personal level, but whereas OceanGate was a
| small business seemingly quite directly run by Rush, SpaceX is
| a large business with plenty of people who know better.
|
| However SpaceX have had certification for human spaceflight
| from the necessary agencies, have a strong safety record -
| comparable to competitors - and seemingly have a development
| process that is producing better hardware than Boeing at this
| point (as seen in the Dragon vs Starliner debacle). That's all
| radically different in approach to OceanGate.
|
| While Musk and SpaceX in general sound like they're pushing the
| "move fast and break things" mantra I think they're more
| nuanced than that. It's more: move fast while things don't
| matter, so we can gather data and experience for when things do
| matter. This isn't much of a defence of Musk mind you, more of
| the team at SpaceX and the wider aerospace community.
| pwthornton wrote:
| SpaceX seems to be doing everything right. Their safety and
| performance record speaks for itself. I also hear that Musk
| is mostly a figurehead for a very well-run company.
|
| Tesla, however, is not doing everything right. Their self-
| driving and collision mitigation software is janky, causing
| deaths, and shoudln't be used on public roads until it is in
| a better state. Musk's insistence on using computer vision
| only reminds me a lot of Rush's stance on mixing materials.
| No one else agrees with either on this, and both made these
| decisions to save money.
|
| Overall, however, Tesla cars are still pretty safe. The cars
| themselves are at the top of safety ratings. The hardware
| part of their cars from a safety perspective is a polar
| opposite of what Rush was doing. Their software is the weak
| point right now -- and probably not that far behind most car
| companies.
|
| I am a big critic of Musk, but I don't think he'd ever have a
| company involved with such poor hardware design and
| engineering like Rush was. SpaceX does amazing work. Tesla
| can fix their software issues if they map their ambitions to
| reality better.
|
| My comment is a bit all over the place, but Musk is
| ultimately a lot more experienced and responsbile than Rush.
| danpalmer wrote:
| You're right that Tesla is in a different place, it's why I
| didn't mention them. I wonder if it's to do with strong
| leadership from people like Gwynne Shotwell at SpaceX (who
| seems amazing from everything I've seen) and perhaps a lack
| of that at Tesla allowing more muskiness to get through.
|
| Tesla's safety standards do seem to be high in tests, but I
| wouldn't be surprised if this is primarily because safety
| tests for cars are a well understood part of car marketing,
| rather than because Musk fundamentally believes Tesla
| should make the safest cars.
| pwthornton wrote:
| Musk certainly likes to talk about how safe Teslas are,
| so it's at least a marketing point. But he also drives
| Teslas himself, so he has a vested interest in them being
| safe. If you are the CEO of GM, you may exclusively drive
| Catalliacs and not care deeply about Chevy safety (beyond
| what the market demands, the market seems to demand more
| of safety from certain brands and segments than others).
|
| Tesla's are also all unibodies, which are safer than
| body-on-frame. Body-on-frame is mostly used in legacy
| trucks and SUVs. The Big 3 sell a lot of body-on-frame
| trucks and SUVs because it is older, higher margin tech.
| You also need to do a lot of extra work to get to the
| same level of safety as a unibody.
|
| Beyond that, EVs in general are safer because they have
| such a low center of gravity. The risk of a rollover in a
| Tesla is low.
| mrguyorama wrote:
| >But he also drives Teslas himself, so he has a vested
| interest in them being safe
|
| You say this in the comment section of an article about
| the death of a CEO in his own craft because he ignored
| safety warnings.
|
| "Hoist by his own petard" isn't even a new saying.
| EricE wrote:
| When Musk starts ranting about not hiring 50 year old
| white guys but instead hiring younger people to encourage
| innovation, I'll be concerned about his logical reasoning
| capabilities. Thankfully he hasn't gone anywhere near
| that kind of batshit crazy rhetoric and photos of Tesla
| and SpaceX employees show a wide spread of folks.
| r2_pilot wrote:
| I appreciate SpaceX's mission and purpose as much as
| anyone, but definitely they do not have a perfect track
| record either, with the recent environmental disaster
| accompanying the 4/20 launch. Somehow it was decided to
| launch on an underdeveloped platform which strew debris and
| dust far in excess of what could be considered "responsible
| engineering" considering what we've known since the Saturn
| V. Having said that, I'd ride in a SpaceX vehicle while I
| have yet to ride in a Tesla, and for many of the same
| reasons.
| sigstoat wrote:
| > Somehow it was decided to launch on an underdeveloped
| platform which strew debris and dust
|
| unless something comes out in discovery, they didn't know
| it was going to do that. and they had a reasonable basis
| for that belief, in the form of the static fire tests.
|
| there are no whistleblowers popping up. i haven't even
| seen any youtubers popping up with "i told you so!"
| claims based on all of the footage that was available of
| the launch site beforehand.
|
| > considering what we've known since the Saturn V.
|
| the saturn V launch facility is an absolutely massive
| pile of earthworks; it's perfectly reasonable to try and
| engineer something smaller than that when you want to
| build a couple dozen of them.
| jhgb wrote:
| > the recent environmental disaster accompanying the 4/20
| launch
|
| "Environmental disaster"? A bit overdramatic, isn't it?
| The amount of "debris and dust" was absolutely minuscule
| compared to regular human activity in a developed country
| like the US.
| x3874 wrote:
| SpaceX, despite run quite well by Shotwell, is still tied to
| Musk. He is known to be a micro-manqging, choleric dictator
| and not an engineer. Have you forgotten the recent disaster
| at Boca Chica? (missing flame trench / diverter)
|
| https://nitter.net/elonmusk/status/1313952039869788173#m
| Everything this guy fiddles / interferes with tends to end as
| a fiasco.
|
| One of Shotwell's most important tasks is to keep this guy
| AWAY, so he won't interfere.
|
| EDIT: I see, the Muskies fanboi gang is again off their
| leashes. Downvote all you want, truth is truth
| gary_0 wrote:
| > SpaceX is a large business with plenty of people who know
| better
|
| Including the President and COO of SpaceX, Gwynne Shotwell,
| an extremely qualified aerospace engineer who has run SpaceX
| for the past 15 years. She's been in the space industry since
| 1988, she knows what she's doing.
| jackmott42 wrote:
| Dragon capsule was designed in close partership with NASA, and
| the Falcon 9 is the most reliable orbital rocket in history
| now.
| mechhacker wrote:
| Not surprising that the Titanium parts are coming out what looks
| like whole.
|
| No sign of the composite cylinder in those pictures.
| jtriangle wrote:
| The composite cylinder likely turned into physics
| mhh__ wrote:
| I think it was physical to start with
| barbazoo wrote:
| > and his son, Suleman Dawood, 19 [...] died in the incident.
|
| I wonder what the liability waiver said that made the father
| think this wasn't a terrible idea.
| zardo wrote:
| Liability wavers don't give you an idea of how likely death and
| injury are.
| meepmorp wrote:
| Right, they only let you know about possible outcomes, not
| the likelihood of any particular event happening during your
| dive. Russian roulette with 1 vs 5 chambers loaded have the
| same set of possible outcomes, but very different odds w.r.t.
| which is most likely when you pull the trigger.
| mrguyorama wrote:
| When even a theme park will have you "be aware" that "death can
| occur", how seriously will you take the same warnings in
| another waiver?
|
| People similarly have signed their souls (ie literally) through
| EULAs as a demonstration that nobody cares.
|
| Hell, we can't even get people to read and acknowledge a one
| sentence error message in software.
| danpalmer wrote:
| The waiver was apparently quite thorough in communicating the
| risk of death. From my reading of coverage of this though it
| sounds like while the waiver was probably correct from a legal
| standpoint, the communication of the likelihood and factors
| contributing to that were _not communicated_ to customers.
|
| Paul-Henri Nargeolet, and Hamish Harding, two of the other
| victims, were somewhat experienced in this, the former having
| travelled to the Titanic on other deep sea submersibles with
| basically flawless track records (Mir? I think, and Alvin), and
| the latter having travelled to the challenger deep in DSV
| Limiting Factor which seems _much_ better built.
|
| Should they have known better? Maybe. This makes me wonder if
| they were actively mislead, rather than being left to make
| their own mind up.
| kayodelycaon wrote:
| > DSV Limiting Factor which seems much better built.
|
| Understatement of the year. Limiting Factor is the only
| manned sub to make multiple dives (4!) into the Challenger
| Deep.
| holler wrote:
| Really cool, had never heard of this before. I just watched
| the documentary on James Cameron and his Deepsea Challenger
| and was similarly impressed by the extraordinary lengths
| the team went to in engineering it. My takeaway was that
| OceanGate likely didn't have anywhere close to the same
| level of design and testing.
| danpalmer wrote:
| There's a good documentary on YouTube from a year or two
| ago on the design and building of the sub, and overall it
| just seemed like such a professional operation, whereas
| OceanGate felt like a DIY operation.
|
| The company that built the LF also seems to have vastly
| more experience building subs.
| Wojtkie wrote:
| Here's the video I think.
|
| https://www.youtube.com/watch?v=pb5j9oeZCm0
| danpalmer wrote:
| Thanks, that's the one! Sorry was on the move on mobile.
| symlinkk wrote:
| If you believe the NY Post, the CEO straight up said the sub
| was "safer than crossing the street" -
| https://nypost.com/2023/06/23/doomed-sub-ceo-said-it-was-
| saf...
| ramesh31 wrote:
| >Should they have known better? Maybe. This makes me wonder
| if they were actively mislead, rather than being left to make
| their own mind up.
|
| This is why true believers are the most dangerous kind of
| idiot. They will lead otherwise reasonable people off a
| cliff.
| dghlsakjg wrote:
| I think that waiver fatigue is a real thing.
|
| I get warned about the dangers of death on basically every
| waiver I sign. I just checked, and I was warned about death
| on the waivers I signed for: bumper cars, a sauna, the local
| rec center, etc... I get that death is technically possible
| at any of these activities, but how are you to differentiate
| between the actual likelihood in the real world.
|
| The waivers have gotten so comprehensive as to not actually
| warn you of the real dangers you might face.
| pasttense01 wrote:
| I think it was probably that they were told the submersible
| had made a number of previous successful trips so assumed it
| would continue to do so--not realizing that the carbon fiber
| material could get weaker and weaker each trip.
| watwut wrote:
| Afaik the waiver talked about death and trauma and so on.
|
| The CEO and company also put in a lot of effort to make it look
| safe. The "waiver is for liability but you are totally safe"
| kind of game.
|
| Going by stories of people who went, company was plain
| manipulative in this regard. I genuinely think that
| millionaires on board were victims prayed on by the
| overconfident guy who died with them.
| quags wrote:
| I wouldn't have done this not because I knew anything about the
| company but think it's inherently risky at those depths. But
| trampoline parks, indoor skydiving, kids school 5k run and
| ropes course all are wavers I signed that stated there was
| chance of death for the activity.
| pengaru wrote:
| > I wonder what the liability waiver said that made the father
| think this wasn't a terrible idea.
|
| Fathers often subject their sons to unnecessary risks in the
| interests of making them more "manly"...
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