The second sentence of the post in question. You should strive for clarity.

You're certainly predictable, which is why I have more than once addressed your expected responses preemptively.

And I don't owe you or anyone else an explanation for how I run this forum or how I deal with members who seem to become obsessed with particular topics or threads, but that doesn't stop you from asking for such, nosiree.

quote:

Previously posted by a1abdj:
I have intentionally researched article prior to the accident to eliminate as much of the reporting bias as possible.

You must be clairvoyant...That's quite a gift!

quote:

Originally posted by nhracecraft:

quote:

Previously posted by a1abdj:
I have intentionally researched article prior to the accident to eliminate as much of the reporting bias as possible.

You must be clairvoyant...That's quite a gift!

Come now, no need for this. a1abdj is stating that he has tried to find articles that were written PRIOR to the accident to eliminate some bias, not that he was aware of the accident beforehand.

quote:

Originally posted by reloader-1:
Come now, no need for this. a1abdj is stating that he has tried to find articles that were written PRIOR to the accident to eliminate some bias, not that he was aware of the accident beforehand.

I actually thought nhracecraft was funny as hell and making a much broader point.

quote:

Originally posted by a1abdj:
No, I didn't forget at all. CET doesn't make manned deep sea submersibles. They do however make deep sea remote operated vehicles using carbon fiber pressure hulls. They've had 100% success rate, zero failures, with hundreds of dives and thousands of hours.

But you think slapping a human in one would cause a failure?

Comparing a human driven submersible to a R.O.V. is like comparing a passenger jet to a flying drone. A human craft and non human one are built entirely different- size, design, safety tolerances, etc. Camera equipment, remote mechanical arms, navigational equipment, etc. do not need oxygen and a certain atmospheric pressure rating for humans.

quote:

I actually thought nhracecraft was funny as hell

I took it as him making a joke.

If you are reading current reporting you're getting everybody and their brother wanting their 15 minutes of fame. That doesn't mean that they're wrong, but there's a lot more to dig through when it comes to separating truth from fiction.

A good example was posted a page or two back. One passenger was claiming that it had to be the hull that failed because he had heard a noise, and it had been used until it finally failed. Right next to that post was a post with an article claiming that the hull had been replaced after that passenger's trip. Both can't be true at the same time. They either continued to use it without heeding warning signs, or it was replaced with something new (and possibly different).

quote:

Comparing a human driven submersible to a R.O.V. is like comparing a passenger jet to a flying drone. A human craft and non human one are built entirely different- size, design, safety tolerances, etc. Camera equipment, remote mechanical arms, navigational equipment, etc. do not need oxygen and a certain atmospheric pressure rating for humans.

Nonsense.

The claim that many here have made is that carbon fiber can not be used successfully as a pressure hull for deep sea use.

I claim that it can be as evidence by Titan using it to make successful trips. CET has also used it extensively with a 100% track record. That doesn't mean that Rush did all of the right things, or that CET is ready to make their own human filled version. It just means that the concept has been proven, and those who claim it's not possible are 100% incorrect because it it has been done, and is still being done in real life.

That's not saying that that there aren't improvements to be made. Several people here have claimed that everything that can be known is currently known. I claim that there are lessons to be learned, improvements to be made, and we will be better off as a result going forward. I'm assuming the Canadian and American authorities believe the same thing, as they are actually conducting a thorough investigation. If it was just "Duh! Carbon fiber!" it would already be case closed.

As pedro asked for and since we're on the topic of ROVs, here's an interesting update:

"The head of the team that discovered the wreckage of the Titan sub said one ROV was lost in the search as it couldn't handle the depth

https://www.insider.com/titan-...ost-in-search-2023-7

Ed Cassano headed the team that recovered the wreckage of the Titan sub.
His company's remotely operated vehicle, Odysseus 6K, found the wreckage of the Titan.
Cassano said that another ROV was lost as it was "beyond their depth capability."

The head of the team that discovered the wreckage of the Titan submersible told a press conference that another ship's remotely operated vehicle (ROV) was lost during the search as it was "beyond their depth capability," adding that this showed the "scope of the effort" that went into the recovery.

Ed Cassano, the CEO of Pelagic Research Services, said his team was part of a fleet of ships involved in the rescue search but that its ROV, Odysseus 6K, was identified as the primary asset to carry out the rescue.

Pelagic's ship was stationed around 250 feet away from Deep Energy, a Bahamian-flagged ship with two ROVs onboard. One was holding at its depth limit of 8,860 feet, while the other had been lost after attempting to send it to the seafloor, Cassano said.

The debris was uncovered near the ship's wreckage, about 13,000 feet beneath the surface in the North Atlantic

"We pushed some things, and everybody pushed some things on this response," he said.

He added that the initial preparations had been for a rescue operation, and he detailed how they planned to "integrate" a lifting line that Deep Energy with Odysseus 6K's lifting capabilities.

But he said it soon became clear that the passengers could not have survived the journey, adding that "by 12 o'clock, sadly, a rescue turned into a recovery."

"Shortly after we arrived on the seafloor, we discovered the debris of the Titan submersible," Cassano said.

Cassano appeared to hold back tears at one point while discussing the operation.

"I have to apologize, we are still demobilizing. There's a lot of emotions, people are tired," he said.

Photos of the debris recovered from the wreckage may explain what caused the submersible to suffer a "catastrophic implosion" as it descended to view the Titanic wreck.

Jasper Graham-Jones, an associate professor of mechanical and marine engineering at Plymouth University, previously told Insider that the carbon-fiber hull likely failed first.

He said it was impossible to be certain just by looking at the photos, but the carbon-fiber hull most likely gave way under the enormous pressure of the ocean depths.

All five passengers onboard the Titan, including OceanGate CEO Stockton Rush, died during the incident.

The US Coast Guard has since said that presumed human remains had also been recovered.

The other passengers were British billionaire Hamish Harding, British-Pakistani Shahzada Dawood, his 19-year-old son, Suleman, and French sub-pilot and explorer Paul-Henri Nargeolet.

It boggles the mind to think of over 12,000 feet of water. The tallest building in the world is "only" ~2700 feet. And this is nowhere near the deepest spot in the ocean, which is three times that.

quote:

Originally posted by a1abdj:

quote:

I actually thought nhracecraft was funny as hell

I took it as him making a joke.

If you are reading current reporting you're getting everybody and their brother wanting their 15 minutes of fame. That doesn't mean that they're wrong, but there's a lot more to dig through when it comes to separating truth from fiction.

A good example was posted a page or two back. One passenger was claiming that it had to be the hull that failed because he had heard a noise, and it had been used until it finally failed. Right next to that post was a post with an article claiming that the hull had been replaced after that passenger's trip. Both can't be true at the same time. They either continued to use it without heeding warning signs, or it was replaced with something new (and possibly different).

quote:

Comparing a human driven submersible to a R.O.V. is like comparing a passenger jet to a flying drone. A human craft and non human one are built entirely different- size, design, safety tolerances, etc. Camera equipment, remote mechanical arms, navigational equipment, etc. do not need oxygen and a certain atmospheric pressure rating for humans.

Nonsense.

The claim that many here have made is that carbon fiber can not be used successfully as a pressure hull for deep sea use.

I claim that it can be as evidence by Titan using it to make successful trips. CET has also used it extensively with a 100% track record. That doesn't mean that Rush did all of the right things, or that CET is ready to make their own human filled version. It just means that the concept has been proven, and those who claim it's not possible are 100% incorrect because it it has been done, and is still being done in real life.

That's not saying that that there aren't improvements to be made. Several people here have claimed that everything that can be known is currently known. I claim that there are lessons to be learned, improvements to be made, and we will be better off as a result going forward. I'm assuming the Canadian and American authorities believe the same thing, as they are actually conducting a thorough investigation. If it was just "Duh! Carbon fiber!" it would already be case closed.

I can certainly understand why you have the logic you have, but I think some additional information from an engineering perspective may be useful. I'll start with the above statement about replacing the hull. It may be possible they replaced the hull, but if they did so with a similar/same design the same failure modes would be present. While I'd agree that the cumulative damage from multiple dives would not be there the statistical nature of void development could actually have the new hull be as bad or worse than the one it replaced. Stockton stated that they couldn't perform NDE (not true, but it's what he said and I presume they didn't do it) so they possibly made an assumption that a new hull would be more resistant and not have as much damage as a used one. It's logical, but not necessarily true.

Your comments about CET follow a certain logic, but aren't seen through the lens of engineering science. I'll use a thought experiment to highlight my point...hopefully it comes through. If you take a solid block (say 1 x 1 x 1 in. cube) of any material that isn't soluble or corrosive in water and is more dense than the water you're dropping it into it will sink to the bottom and just sit there barring any other forces acting on it. In addition, no matter how deep that water is the hydrostatic pressure on the material will essentially never drive failure of that block. There will be a volume change that is proportional to the bulk modulus of that material (material property) and the pressure it sees, but you won't fail it. Now, if you put a small little cube of air inside at atmospheric pressure we have a pressure vessel with a differential pressure across the wall of that vessel. As we increase the size of that cube (from say 1x1x1 in. to 1x1x1 ft.) then the thickness of that wall has to get proportionally bigger in order to withstand the same pressure.

Now what the heck does this have to do with CET's statements? Well, I'm sure they do put their UUV/ROVs down to similar depths and I'll take them at their word that they use CFRP materials as a housing...but the UUV is more like the 1x1x1 in. block and the OceanGate is more like the 1x1x1 ft. block in this analogy (real volumes/dimensions are of course different). So the submersible carrying humans has to be thicker by necessity in order to keep the stresses at a manageable level. There are a few things I see with this. The first is that it's possible that OceanGate has a much lower factor of safety/allowable stress than CET - this is a design issue exacerbated by the lack of NDE. The second is that because it needs to be larger in size to fit humans the thickness of OceanGate's hull is much more difficult to manufacture. I think I read somewhere in another post that they are on the order of 5 in. thick. That is a thick composite and it's difficult to get consistent properties, good bonding between fiber and matrix, minimize voids etc. through the thickness of composite that is that thick. What I'm trying to say is that not all designs scale in a way that a smaller version will be successful when scaled up or vice versa. It's quite common that physics just doesn't work that way.

I'd also consider the source speaking. The CEO of CET is not an engineer, he's an economist by background and their CTO is an anthropologist by training. This doesn't mean that they can't have informed opinions on these matters and some of the other folks on their website are clearly experts in the domain...but I'd take anything they directly say with a grain of salt. I've said many things to my business stakeholders, most of whom are trained engineers, and then see them spin it incorrectly when relaying that information.

One other aspect of this that has been discussed, but without much technical detail is the material response and the ability of the material to absorb damage and energy. In comparison to steel or other more traditional materials, CFRP is brittle. Is it like glass, no, but it definitely has much lower strain to failure and much lower energy to failure. This makes it much less tolerant to any sort of damage that may occur. The below stress strain curves show conceptually what I mean. Composites are generally classified as brittle and steel and titanium alloys are more ductile. This extra ductility generally correlates with a higher fracture toughness as well. This means that these more ductile materials are more tolerant of cracks and if a crack forms it takes more stress to get it to propagate. I studied fracture and fatigue of polymers quite a bit when I was a grad student as it was the metric I was using to show how my material system improved the fatigue life of polymers (like the matrix in the CFRP) and also the fracture toughness. Even with this steel is going to be about 10-100x more crack resistant than polymers.

Eddie Cassano (Pelagic Research Services) was one year ahead of me in the HS we attended and I was very good friends with him and best buds with his younger brother since 1st grade. The entire Cassano clan are good peeps and welcomed all of us like family into their home.

Many good times were spent hanging out at their house. Sometimes we’d ask “Where’s Eddie?” and then be informed that he was practicing his underwater Scuba skills in the family pool.

Eddie was always brave, bold, adventurous and way more mature then the rest of us knuckleheads (it’s what our ski racing coach called us), and our knick-name for him was sometimes “Captain Kirk”.

It is no surprise to me at all that Ed Cassano and his company were called upon to assist in finding and recovering the wreck of the the Titan and the remains of its crew and passengers.

Great job Eddie!!

quote:

Originally posted by a1abdj:

The claim that many here have made is that carbon fiber can not be used successfully as a pressure hull for deep sea use.

I claim that it can be as evidence by Titan using it to make successful trips.

I can walk blindfolded across a crowded street during rush hour 5 times (if I'm lucky enough). That DOES NOT mean it is a good idea or 'safe.'

Just because it didn't implode the first 4 times does NOT mean that it was a 'safe' design or a 'safe' submersible. The passengers on the first dives just got lucky.

Just like the Hindenburg made quite a few successful voyages - but that ONE bad one forever rules out the use of hydrogen in airships. DeHaviland Comet airliners were great - until a series of fatal crashes revealed the design was susceptible to extreme metal fatigue around the corners of the large square passenger windows. Lockheed Electra airliners were also really great aircraft, UNTIL a series of crashes revealed critical design flaws that needed to be fixes. The shuttle fleet made a LOT of successful flights until Challenger showed a critical design flaw in the solid rocket boosters.

Your 'logic' is in error in assuming that several 'successful' dives validates the Titan's design. Or, we have ENTIRELY different views of what 'used successfully' means.

quote:

Originally posted by Hound Dog:

quote:

Originally posted by a1abdj:

The claim that many here have made is that carbon fiber can not be used successfully as a pressure hull for deep sea use.

I claim that it can be as evidence by Titan using it to make successful trips.

I can walk blindfolded across a crowded street during rush hour 5 times (if I'm lucky enough). That DOES NOT mean it is a good idea or 'safe.'

Just because it didn't implode the first 4 times does NOT mean that it was a 'safe' design or a 'safe' submersible. The passengers on the first dives just got lucky.

Just like the Hindenburg made quite a few successful voyages - but that ONE bad one forever rules out the use of hydrogen in airships. DeHaviland Comet airliners were great - until a series of fatal crashes revealed the design was susceptible to extreme metal fatigue around the corners of the large square passenger windows. Lockheed Electra airliners were also really great aircraft, UNTIL a series of crashes revealed critical design flaws that needed to be fixes. The shuttle fleet made a LOT of successful flights until Challenger showed a critical design flaw in the solid rocket boosters.

Your 'logic' is in error in assuming that several 'successful' dives validates the Titan's design. Or, we have ENTIRELY different views of what 'used successfully' means.

I was trying to avoid answering this question directly, but this is exactly how I view it as well. Even down to the examples you used.

quote:

Originally posted by Lefty Sig:
So he bought a tube from a company that designed it in a computer and tested scale models to show it could withstand the static pressure requirement. I see no info in any of the posted quotes for cyclic load testing to full design pressure until failure to know what the cyclic limit is. And I wouldn't trust anything less than multiple full size samples tested because of the potential for variation in the winding process. Say one fails at 20 cycles and one at 40 cycles due to variation in manufacturing. Hard to know with a sample size of one.

When you cannot afford to build and test full scale prototypes to failure, you have to use time proven and validated design principles based on the whole of the historical experience with actual examples that have been successful in the field.

And that's for everything in this case - the tube, the bonding method of the endcaps, etc.

What keeps getting missed is the entire PROCESS:

Design, design validation testing to failure under static and cyclic loading, manufacturing, manufacturing validation testing to failure of multiple samples, slow ramp up in service at progressive depths until full service depth is reached - all UNMANNED. Slow ramp up of manned missions at progressive depths until service depth is reached. All the while inspecting for damage/cracks after every dive (probably with X-rays and/or ultrasonics), base on KNOWN cyclic failure data from previous testing.

This is how we Engineers (M.E. U of IL 1994) do things. A similar process is followed for most complex engineered things. Cars, engines, aircraft, spacecraft, etc. When things are so big, costly, and/or complex you can only make one and can't test to failure, you have to be VERY conservative in the design and construction to make for damn sure it never fails.

But all this was too costly and time consuming for Rush. And he knew better than all those old white experienced submariners, until he didn't know better.

I just noticed that Lefty Sig is an Illinois alum. Oskee wow-wow Lefty Sig.

This message has been edited. Last edited by: Kampy,

OceanGate CEO used college interns to design sub’s electrical system: report
By Yaron Steinbuch
July 3, 2023 9:30am Updated

College hired college interns to design the electrical systems for the ill-fated Titan submersible that killed him and four other people, according to an explosive new report.

Rush, who allegedly ignored safety warnings while charging wealthy tourists $250,000 for dives to the Titanic shipwreck, hired students from Washington State University to work on the critical systems, The New Yorker reported.

“The whole electrical system — that was our design, we implemented it, and it works,” a former intern told the college paper in February 2018, according to the mag.

“We are on the precipice of making history and all of our systems are going down to the Titanic. It is an awesome feeling!” he added.

Meanwhile, OceanGate’s former director of marine operations and chief pilot has said the Titan was a “lemon” and not safe to dive in 2018, The New Yorker also reported in its wide-ranging piece.

The ex-student, Mark Walsh, had been the treasurer of WSU’s Institute of Electrical and Electronics Engineers club when OceanGate’s director of engineering, Tony Nissen, described some of the company’s challenges, according to the school paper.

Walsh said he and fellow students volunteered to offer solutions.

“Tony said, ‘OK, you’re hired,’” said Walsh, who graduated in 2017 with a degree in electrical engineering and then joined OceanGate full-time as the company’s electrical engineering lead.

“If electrons flow through it, I’m in charge of it,” he told the WSU paper with a laugh, adding that he was leading a team of five, including Nissen and two WSU interns.

Nissen recommended senior Doug Yamamoto because of his software engineering experience, the WSU report said.

“I like that we have a close relationship with WSU Everett because the interns have been so great,” Walsh said. “They’ve been taught right at WSU Everett, so this summer we’re going to be hiring more.”

On June 22, WSU told local outlet the Everett Herald that “it does not have an alliance with OceanGate.

“We are aware that some of our graduates have worked at OceanGate. To our knowledge, one graduate currently works there. We are not privy to what OceanGate projects WSU Everett alumni have been involved in or what their roles may have been outside of publicly available information,” it added.

OceanGate also used interns from Everett Community College’s Ocean Research College Academy, but the school stopped offering internships with the company in 2019, according to the Herald.

The New Yorker also reported about David Lochridge, who was fired as OceanGate’s head of marine operations after he raised concerns about the company’s testing methods.

In 2018, deep-sea exploration specialist Rob McCallum contacted Lochridge after his ouster.

“I’d be keen to pick your brain if you have a few moments,” McCallum emailed him, according to the mag. “I’m keen to get a handle on exactly how bad things are. I do get reports, but I don’t know if they are accurate.”

He added: “Stockton must be gutted. You were the star player … and the only one that gave me a hint of confidence.”

Lochridge reportedly replied: “I think you are going to [be] even more taken aback when I tell you what’s happening,” adding that he would share his opinion of the Titan in private but was afraid of retaliation from Rush because of his “influence and money.”

“That sub is Not safe to dive,” Lochridge wrote, according to The New Yorker.

“Do you think the sub could be made safe to dive, or is it a complete lemon?” McCallum reportedly replied. “You will get a lot of support from people in the industry. Everyone is watching and waiting and quietly s—ting their pants.”

Lochridge responded: “It’s a lemon.”

“Oh dear, oh dear, oh dear,” McCallum emailed, according to The New Yorker.

In 2018, Lochridge found “several critical aspects to be defective or unproven” with the Titan and wrote a detailed report outlining his concerns, including about the craft’s carbon-fiber hull, which experts now believe could have led to the implosion.

“Until suitable corrective actions are in place and closed out, Cyclops 2 (Titan) should not be manned during any of the upcoming trials,” he reportedly wrote.

Rush, who was “furious” with Lochridge’s report, called a meeting in which OceanGate leadership insisted that no hull testing was necessary, according to the mag.

Instead, an acoustic monitoring system would reportedly be used to detect fraying fibers to alert the pilot to the possibility of catastrophic failure “with enough time to arrest the descent and safely return to surface.”

But Lochridge’s lawyer wrote in a court filing that “this type of acoustic analysis would only show when a component is about to fail — often milliseconds before an implosion — and would not detect any existing flaws prior to putting pressure onto the hull,” The New Yorker reported.

OceanGate’s lawyer wrote that “the parties found themselves at an impasse — Mr. Lochridge was not, and specifically stated that he could not be made comfortable with OceanGate’s testing protocol, while Mr. Rush was unwilling to change the company’s plan,” the mag said.

https://nypost.com/2023/07/03/...yp&utm_medium=social

quote:

Originally posted by a1abdj:

quote:

I actually thought nhracecraft was funny as hell

I took it as him making a joke.

If you are reading current reporting you're getting everybody and their brother wanting their 15 minutes of fame. That doesn't mean that they're wrong, but there's a lot more to dig through when it comes to separating truth from fiction.

A good example was posted a page or two back. One passenger was claiming that it had to be the hull that failed because he had heard a noise, and it had been used until it finally failed. Right next to that post was a post with an article claiming that the hull had been replaced after that passenger's trip. Both can't be true at the same time. They either continued to use it without heeding warning signs, or it was replaced with something new (and possibly different).

quote:

Comparing a human driven submersible to a R.O.V. is like comparing a passenger jet to a flying drone. A human craft and non human one are built entirely different- size, design, safety tolerances, etc. Camera equipment, remote mechanical arms, navigational equipment, etc. do not need oxygen and a certain atmospheric pressure rating for humans.

Nonsense.

The claim that many here have made is that carbon fiber can not be used successfully as a pressure hull for deep sea use.

I claim that it can be as evidence by Titan using it to make successful trips. CET has also used it extensively with a 100% track record. That doesn't mean that Rush did all of the right things, or that CET is ready to make their own human filled version. It just means that the concept has been proven, and those who claim it's not possible are 100% incorrect because it it has been done, and is still being done in real life.

That's not saying that that there aren't improvements to be made. Several people here have claimed that everything that can be known is currently known. I claim that there are lessons to be learned, improvements to be made, and we will be better off as a result going forward. I'm assuming the Canadian and American authorities believe the same thing, as they are actually conducting a thorough investigation. If it was just "Duh! Carbon fiber!" it would already be case closed.

a1abdj

A request? When you quote someone, you tend to leave out who you are quoting. It makes it much more difficult to follow the conversation.

Thanks SL. At the 1100 min. mark or so I can imagine a similar fate to the sub. FWIW at this point.

This fuckin' guy

James Cameron denies ‘offensive rumors’ that he’s in talks for film about doomed OceanGate submersible

quote:

"I don’t respond to offensive rumors in the media usually, but I need to now," the "Titanic" director wrote on his Instagram Story. "I’m NOT in talks about an OceanGate film, nor will I ever be."

Oh, you're offended?

If- IF it's only a rumor- and I'm not sure about that- do you know why such a rumor would start, Jimmy Boy? Any idea? It started because it's exactly the kind of fucking shit you would do. Nobody would put it past you, not with your Titanic obsession, and I can see "changing your mind" in two or three years.

He certainly didn't mind making a movie about the 1500+ lives lost in 1912... Maybe he is offended because there were only 5 lives lost here and there wouldn't be enough profit in it.