Live data from Hacker News

Debris found came from missing Titan sub, says friend of passengers

bbc.com

631–640 of 1001 posts

Re: Debris found came from missing Titan sub, says friend of passengers

#631

Here are a couple of quotes I pulled from the USCG press release: > "debris is consistent with a catastrophic implosion of the vessel" > "1600 feet (487 meters) from the wreck of the Titanic" > "it is a smooth bottom", "there is no wreckage of the Titanic in the area" > "size of the debris field is consistent with an implosion in the water column" > "there doesn't seem to be any connection between the noises and the…

I'm really curious about the carbon fibre design, I'm not a material expert but I do dive and for tanks they work because of the internal pressure of tank. The 'weaving' is supposed to be link connecting your two hands together interlocking fingers, in one direction you will meet a full resistance, but in the opposite direction your fingers will unlock. I have no idea but seems to me if there is external pressure the…

Your intuition is spot on, carbon fiber is much better at tensile loads than compressive loads.

Tensile load capacity is pretty much the resin that keeps the fibers from moving.

The most I could find about the design

> The entire pressure vessel is comprised of two titanium hemispheres, two matching titanium interface rings, and the 142 cm (56") internal diameter, 2.4-m (100") long carbon fiber wound cylinder – the largest such device ever built for use in a manned submersible.

suggest that yeah, they relied entirely on its compressive strength of it

Re: Debris found came from missing Titan sub, says friend of passengers

#633
post #436
post #276

Earlier quoted context omitted.

Was interested by this comment and wanted to note a few things. The Titan is significantly smaller (in terms of length ~1/10th the size although obviously displacement is the real measure)[1][2]. And the depth of the implosion is about 4x deeper[1][3]. So there are things that could definitely affect the sound signature. [1] https://en.m.wikipedia.org/wiki/ARA_San_Juan_(S-42) [2] https://en.m.wikipedia.org/wiki/2023_…

Yes, and as far as I can tell it's not even certain that what was picked up from the San Juan was an implosion. But on the other hand, the Polar Prince was sitting right on top of the Titan listening for pings, and apparently it didn't hear anything. I'm not suggesting anything nefarious, I'm just hoping someone who understands these things better than I do comes along.

I'm speculating, but their ping detector may have had a filter for the frequency they were interested in. A low frequency explosion could easily have been ignored.

Re: Debris found came from missing Titan sub, says friend of passengers

#634
post #258

Earlier quoted context omitted.

"Two months later, OceanGate faced similarly dire calls from more than three dozen people — industry leaders, deep-sea explorers and oceanographers — who warned in a letter to its chief executive, Stockton Rush, that the company’s “experimental” approach and its decision to forgo a traditional assessment could lead to potentially “catastrophic” problems with the Titanic mission." https://www.nytimes.com/2023/06/20/us…

I don't understand why they didn't just drop it to the bottom of the ocean without people hundred times to see if it still holds. Who experiments with a crew in the age of remote control sensors and computers?

The carbon fiber hull has a limited cycle life. It's designed for a single-digits number of dives, and it becomes weaker on each cycle.

Re: Debris found came from missing Titan sub, says friend of passengers

#635

Earlier quoted context omitted.

Part of me has been wondering if the noises being heard might be an unexpected discovery of a military (Russian, Chinese, US) submarine operating in the general area. Don’t they submerge for long periods of time without comms?

They do, but not the depths we're talking about (12,500 feet) https://navalpost.com/how-deep-can-a-submarine-dive/ The depth limits of the most known nuclear powered submarines’ depth limits, as follows; Typhoon-class: Test depth 900 m (3,000 ft) Astute-class: Over 300 m (984 ft 3 in) Akula-class: 480 m (1,570 ft) test depth for Akula I and Akula I Improved, 520 m (1,710 ft) for Akula II and III, 600 m (2,000 ft) max…

Russia has a Losharik nuclear submarine that was tested up to 2500m (8200ft) if Wikipedia is to be believed. It got in the news when it had a fire that killed half a dozen decorated officers. USA probably has something similar.

Re: Debris found came from missing Titan sub, says friend of passengers

#636
post #457

Earlier quoted context omitted.

Do you have any details about why it was a death trap? I watched one video that complained about off the shelf parts being used, but the two examples was an RV light (not safety related) and the gaming controller (which they had multiple back ups). They also claimed to have been reviewed by Boeing and University of Washington. There was 7 different mechanisms that could force a return. Some of those were purely mecha…

James Cameron had some insightful commentary on why the sub was intrinsically dangerous: https://www.youtube.com/watch?v=rThZLhNF_xg

+1 thank you for the link. this was exactly what I was looking for.

Re: Debris found came from missing Titan sub, says friend of passengers

#637
post #583

Earlier quoted context omitted.

And the 19 year old who didn't want to go on the submarine but wanted to spend time with his dad? Was he reckless? Was he worth searching for?

Do we know he did not want to go?

According to his aunt: https://www.nbcnews.com/news/world/titanic-submersible-shahw...

Re: Debris found came from missing Titan sub, says friend of passengers

#638

Stockton Rush (OceanGate's CEO) was known in the Seattle tech community [0] My understanding (very much not first hand) is that he was seen as an expert in the specific engineering disciplines necessary to safely build and operate deep sea submersibles like Titan. He was also apparently a father to members of the Seattle tech community, who are no doubt grieving at the moment. Please remember that, for some members o…

He killed 4 people with his negligence. Not someone to remember as a hero.

Re: Debris found came from missing Titan sub, says friend of passengers

#639
post #425

Earlier quoted context omitted.

Good video. Some excerpts: "If you're not breaking things, you're not innovating. If you're operating in a known environment as most submersible manufacturers do, they don't break things." (8:49) "Our rule is we risk capital, we don't risk people." (9:56) "We used the same prepreg that's used on the 787." (11:15) And my favorite: "When you're outside the box, it's really hard to tell how far outside the box you reall…

> It's a strong indication of bullshit -- name dropping that doesn't have anything to do with the subject matter It means you're using a material that's been vetted over decades in life-critical applications in harsh conditions by expert engineers all over the world. Aerospace aluminums today are derived from Japanese alloys invented in WW2 and were a major innovation in metal aircraft. It's much more expensive than…

> It means you're using a material that's been vetted over decades in life-critical applications in harsh conditions by expert engineers all over the world.

If I start using a screwdriver to hammer in nails, it doesn't matter how many expert engineers use screwdrivers. I'm using it for a purpose it is unfit for.

Just because it's aircraft grade doesn't mean that it is (or isn't) suitable for building a submarine.

Re: Debris found came from missing Titan sub, says friend of passengers

#640
post #301

Earlier quoted context omitted.

I hope the other souls onboard fully understood the risk of death, otherwise that isn't fair to them. To relate it to flying in an airplane, “If you take one flight a day, you would on average need to fly every day for 55,000 years before being involved in a fatal crash.” I'll take those odds. Take a deep dive in an experimental vessel with public safety concerns expressed over years, nope I'm out.

They all had to sign multi-page waivers that mention "death" no less than three times on the first page.

People have to sign those waivers very often for significantly less risky activities like going ziplining, so let's not pretend signing a waiver is the same as actual informed consent.
Post reply on HN