[Thad E Ginathom]

Originally Posted by mohansrides

Let us be very clear here. The amount of risk and the circumstances surrounding this accident have little to no comparison to other activities that carry risk. ... ... ... This submersible though; this was certain death. If you survived it, that is what would be remarkable as it would be against the odds. The risk profile in the Titan case was completely off the charts. It was utterly insane.

I don't recall how many deep-ocean trips this thing had done, but it was not its first. So survival was not against the odds. Even if they were odds you or I would not like.

Really, how is this comparable to most other recreational activities like trekking or motorcycling or jungle safaris?

All such activities are on a scale of danger.

How about sailing? Fall overboard from a yacht, and you stand a very good chance of being dead, even with your mates trying to find and rescue you. How about single-handed sailing? Fall overboard and you are dead. There is a substantial number of people out there in their yachts right now.

Now coming to the ink online equating these guys to explorers and whatnot!! Really, what a load of utter garbage!! Explorers are pioneers who venture into the unknown to expand the cause of all mankind.

Explorers are people out exploring, various distances from their comfortable homes, and at various levels of danger. I think you set the bar for the description far too high!

The more money, the greater the choice. A friend of mine paid for a trip crewing on a traditional sailing boat from the Galapagos Islands down to the Antarctic. She's not rich. These guys paid for a trip to the deep ocean; others have paid to get to another extreme, high above the earth.

Why risk life (and it was high-risk) for a quick look at an old ship in murky waters? I wouldn't. You wouldn't either. It was their choice. One of them, at least was certainly an explorer, with many and varied expeditions to his credit.

Let me move on to the question: what next?

It seems like this was a one-man business. One boss, that is: everything was driven by him. Someone should be held accountable for this disaster --- but that man is among the dead.

[mohansrides]

Originally Posted by Thad E Ginathom

I don't recall how many deep-ocean trips this thing had done, but it was not its first. So survival was not against the odds. Even if they were odds you or I would not like.

All such activities are on a scale of danger.

How about sailing? Fall overboard from a yacht, and you stand a very good chance of being dead, even with your mates trying to find and rescue you. How about single-handed sailing? Fall overboard and you are dead. There is a substantial number of people out there in their yachts right now.

Just to be clear, I did not deny the dangers in any other activity. I just said the scale of danger here is far from that in any other activity. Sailing or solo sailing may carry danger. But, as you yourself said, loads of people are doing it and we don't have reports of them offing themselves on a weekly basis. And also like you said, in many activities, rescue is a realistic option. Here the chances of rescue are slim to none (from what we are learning) because of the circumstances - no tethering; no accompanying vessel; not a self-powered vessel; ocean depths being inky blackness with huge amounts of pressure. This is OceanGate's 3rd year of operation and it lost a load of passengers.

So, clearly the risk levels are disproportionate here in this case.

Still, I have specifically said that I don't have a problem with people making their own choice to be stupid. My issue was with that businessman dragging his young son along on this foolhardy journey.

Originally Posted by Thad E Ginathom

Explorers are people out exploring, various distances from their comfortable homes, and at various levels of danger. I think you set the bar for the description far too high!

If everyone "exploring" is an explorer, I too am one because I was poking around the ditch that surrounds our house. And by extension every idiot making a cringe-worthy YouTube video is now to be termed a "filmmaker" because you know, they are making "films". NOT!!

P.S.

The only other popular activity that I can think of that comes remotely close to this level of risk is climbing Everest or K2 or whichever peak. But, even those are becoming fairly commonplace with more and more people successfully summiting (than those dying). More importantly, all those activities are regulated by govt, with quite a bit of assistance built in.

[V.Narayan]

Originally Posted by Thad E Ginathom

Could they have been of the opinion that every dive was such a test, whereas every drive was actually stressing the vessel?

Very pertinent question. Some of the answer is in the two posts copied below. Short answer is that each dive down to ~3800 metres is weakening the hull.

Originally Posted by V.Narayan

1. Military submarines that go down to but a fraction of the Titanic's depth - 500 metres vs 3800 metres are always, but always, built of the same material - typically a steel alloy and only welded never fused together by glue as was the case here with a composite -cum- titanium pressure hull. Gluing weakens structural integrity under pressure.

2. Military submarines are subject to X-ray style examination once or twice or thrice in the subs life across the entire pressure hull to identify microscopically thin fractures not visible to the eye. I assume they are treated in some way. Was this vessel ever checked like this? It had done multiple dives over a few years. At 380+ atmospheres of pressure it can be safely assumed microscopic cracks would have occurred.

3. Carbon fibre when under stress does develops hairline and microscopic fractures.

Originally Posted by AirbusCapt

Carbon fibre by its nature is a blended composite structure. Its stress points and points of failure cannot be measured unlike metals like steel or titanium. The standard checks (ultrasound) to measure cracks or cavities in metals doesnt work well on carbon fibre. Also metals have a predictable failure path, however carbon fibre can shatter suddenly and immediately.

A pressure vessel is always made with titanium or steel blended alloys, this was probably the first vessel made using carbon composites. Also after multiple dives, they made no attempts to test the structure.

A pressure hull compresses with each descent and expands with each ascent. That causes microscopic fractures that at some point will collapse dramatically in a nano second if not monitored and attended to. I don't know of any technology that addresses such cracks in carbonfibre.

[no_fear]

Originally Posted by AirbusCapt

Carbon fibre by its nature is a blended composite structure. Its stress points and points of failure cannot be measured unlike metals like steel or titanium. The standard checks (ultrasound) to measure cracks or cavities in metals doesn't work well on carbon fibre.

I work a lot with carbon fiber for my motorbike designs, and from my limited understanding - the fibers are bonded with epoxy. When carbon fiber starts stressing, the epoxy shears also and creates micro pockets.

In this case, water (on a molecular level) entered into the epoxy layer pockets and sheared the carbon fiber layers apart, causing the instant implosion.

As Airbus Capt put it - carbon fiber points of failure cannot be detected or measured. Unlike metals (especially steel) which can flex and be returned to its original shape, carbon fiber does not do that. The sub had done a few dives already so the carbon fiber probably started shearing and cracking along with the epoxy but its not visible to the naked eye.

ps. I have snapped carbon fiber by mistakenly standing on a sheet while working. However I could not break the sheet while flexing or bending it. Goes to show how the composite behaves very differently

[Thad E Ginathom]

Originally Posted by Thad E Ginathom

Could they have been of the opinion that every dive was such a test...

Originally Posted by V.Narayan

Very pertinent question. Some of the answer is in the two posts copied below...

Yes, but my question was not so much about the physical facts as about what OceanGate might have thought. Which might not actually have been good engineering/physics.

[Jeroen]

Originally Posted by V.Narayan

Very pertinent question. Some of the answer is in the two posts copied below. Short answer is that each dive down to ~3800 metres is weakening the hull.


A pressure hull compresses with each descent and expands with each ascent. That causes microscopic fractures that at some point will collapse dramatically in a nano second if not monitored and attended to. I don't know of any technology that addresses such cracks in carbonfibre.

Although it might be a poor comparison, I keep thinking about the Comet. Nobody had really been able to think through what the pressure cycles on the cabin did in terms of fatigue.

I really don’t know much about carbon fibre. But I would like to understand some more how repeated pressure would manifest itself.

By the way carbon fibre can be tested (non destructive) in many ways. Even using X rays, although there are some limitations. Lots of articles if you search integrity testing carbon fibre.

A simple overview from our friends at Wikipedia:

The aerospace industry relies on thermography testing to help detect defects in the carbon fiber components.[4] Ultrasonic testing of CFRP parts is the most popular form of NDT testing.[5] Ultrasonic testing allows researchers to find any anomalies in the thin laminar composites.[5] Ultrasonic testing only works with parts that are no thicker than 50mm.[5] Radiographic testing utilizes short wavelength electromagnetic radiation. The wavelength is so small that it can penetrate the CFRP while light cannot.[5] X-ray testing can detect voids, porosity, inclusions, trans-laminar cracks, resin-to-fiber ratio, non-uniform fiber distribution and fiber orientation, such as fiber folds, wrinkles or weld lines.[5] A flaw of X-ray testing is if the defect is perpendicular to the x-ray beam, the defect will not be detected.[5] Thermography plays a major role in the aerospace industry. This test is used to detect any defects that could cause the carbon fiber component to fail resulting in a catastrophe.[4] Two types of thermography exist active and passive. Both of these methods save money because the part that is being tested stays intact. They are also efficient because they are able to scan large areas at a time.[4] As carbon fiber composites are highly individual in shape and material composition, novel NDTs are an emerging and sought-for application.[6] Applicable technologies are radio wave testing,[7] high frequency eddy current testing,[8] thermography, shearography,[9] air-coupled laser ultrasonics and terahertz scanning

Above appears to be mainly related to aviation industry, so not sure if such tests, or other test are relevant for submersible testing.

I came across below article which provides a little more detail on Titan design history. I was surprised to read there has been an earlier carbon fibre submersible, the DeepFlightChallenger, of Steve Fossett (remember him). But it never dived, as Steve managed to kill him in a different way.

https://www.compositesworld.com/arti...ep-deep-waters

Jeroen

[thanixravindran]

Originally Posted by mohansrides

Typically I don’t comment on topics that I can’t offer an experiential perspective on.
.
.
Now coming to the ink online equating these guys to explorers and whatnot!! Really, what a load of utter garbage!! Explorers are pioneers who venture into the unknown to expand the cause of all mankind. Blowing a bunch of money to go and see a shipwreck (that has been studied a million times already) hardly qualifies as pioneering. Really, these 5 dudes aren't equal to Vasco da Gama or Christopher Columbus or any such person. These were rich and bored folk who made a reckless decision without understanding the value of life.

That is some harsh words there for the departed souls. While you are focussed on their trip to see a shipwreck, I see they were indeed testing the depths of ocean with a vessel an amateur can assemble and go. Unfortunately, they failed and paid the price but I am sure some one else will make it in the future. There is a whole world deep under the ocean that will be 'explored'.

PS: I am not going to argue on the objective and the aftermath of the 'expeditions' of Vasco da Gama or Christopher Columbus.

[MegaWhat]

Although far from a material expert, I've worked with composite structures (like carbon or glass fiber) a bit. The key difference in my understanding is how composities behave in fatigue loads as compared to metals. Metals are relatively malleable and can expand and contract more freely than composites - as they would for a submersible made from metal as it goes to insane depths and rises back again. Composites dont behave the same way and the behaviour under cyclic loading can be extremely non-linear. The submersible could safely take people ~3000m below sea level one day and suddenly develop a crack at ~2000m below sea level the very next day. Technically speaking, composites are a weird choice for a submersible. The maximum yield strength might be higher than steel, but behaviour under dynamic/cyclic loading is much more predictable with metal.

[Thad E Ginathom]

Originally Posted by MegaWhat

Although far from a material expert, I've worked with composite structures (like carbon or glass fiber) a bit. ...

That's very interesting and makes me appreciate metals!

How about the lamination process by which they are made? Ideally, I suppose that each layer is fused, but is that actually the case? Would the compression and expansion tend to delaminate? Would the cylindrical geometry affect this?

I'm now remembering something that I read about titanium when I was a hobby jeweller: that it work hardens quickly and cannot be annealed (if I recall correctly).

[no_fear]

Originally Posted by V.Narayan

There is so much of unfairness in our world where we worship Mammon.......Frankly, I did not want to say it so openly on the forum but these are super-duper rich who consciously chose a seriously life threatening adventure and now the US, Canadian and French tax payers are funding this rescue attempt!

V.Narayan raised a very interesting point on how millions have been spent on this search, while the Greek migrant boat crisis barely made headlines for a day. I won't discuss about the human cost or the injustice, as Mr. Narayan rightly said, this is not the forum for it.

But I do want to explain from an economic sense why the US Coast Guard (USCG) search and rescue spend so much time and money in these sort of events, while Europe does pretty much nothing.

Ever since the USCG came under the Department of Homeland Security, one of it's biggest mandates has been the war on drugs and to combat drug trafficking. Billions / Trillions have been spent on this, and the USGC got a whole load of $$$ to upgrade its systems.

The Caribbean in the past 10 years has become the de facto pit stop for all drug traffickers. From Mexico / Colombia, the shipments are first moved to islands in the Caribbean. Then the the drug routes split into 3 - one heads North East to Florida / Georgia, the 2nd heads to Rotterdam / Hamburg, and the third goes to West Africa.

Smugglers are adept in using submersibles and light wing aircraft in transporting the goods. It becomes a challenge and extremely difficult for the USCG to find them, and thanks to a lot of military and government support, now have the tools to track small planes and subs that were not electronically visible before.

As such the USCG deploys their fleet 24/7 collecting data on all the movements, studying them and understanding how to fight the trafficking game.

The Titan Sub incident is a god-send in the guise of a simulation. USCG along with the other acronyms, conducts such simulations of finding a sub-oceanic ping on a weekly basis. For them a real life incident like this generates a whole load of data, especially how the systems work, what data is being used, and how to use this data to further enhance surveillance capabilities.

Spending millions on finding a sub is nothing compared to the expertise and data gathered from this exercise, which will shape the policy and budget for USCG to keep fighting the drug traffickers.

[skanchan95]

Debris from the Titan wreckage brought to shore.

https://youtu.be/KDOcIoFlEoQ

[sandeepmdas]

Originally Posted by skanchan95

Debris from the Titan wreckage brought to shore.

Two images of debris being salvaged. From a Reddit community.

[kiku007]

Originally Posted by mohansrides

Typically I don’t comment on topics that I can’t offer an experiential perspective on. But this time I felt the need to say something. Especially since I have waited a while and the feeling of sadness hasn't entirely diminished. Not so much for the 4 other passengers on the vessel; those guys were stupid and I have zero empathy for them. More on them later.

But that 19 year old kid who had his whole life ahead of him!! Man, that dude was just plain unlucky to have had a thoroughly idiot father.

Still, I am quite ok with people deciding for themselves. But this businessman who dragged his son along. I can't think of enough abuses to hurl his way.

https://www.ndtv.com/world-news/shah...r-aunt-4145661

This dude reminds me of the mom who asked her son to hand by a bedsheet some 8 floors above the ground (in Noida if I recollect correctly) to fetch something from a balcony below!! There really should be some sort of entry barrier before people are allowed to have kids. As a parent you have but ONE job!!

I believe your opinion on Shazada Dawood’s bad parenting is based on the telephonic interview given by Suleman’s aunt.

However, this is what Christine Dawood, Suleman’s mother had to say, "In her first interview, Mrs Dawood said she had planned to go with her husband to view the wreck of the Titanic, but the trip was cancelled because of the Covid pandemic.

"Then I stepped back and gave them space to set [Suleman] up, because he really wanted to go," she said."

Link: https://www.bbc.com/news/world-us-canada-66015851

It is really up to you on who’s statement you want to believe to be true.

In my opinion, a 19 year old in a billionaire household in the 21st century is reasonably well informed to be capable of making their own choices. Are those choices wise or not is a different question.

I don’t know why parents send their primary school children in overcrowded autorickshaws or on two-wheelers with the kids not wearning helmet, even though the parents can well and truly afford better safer transportation for their children. These kids don’t choose to be transported like that.

I feel for the loss of all five lives here and even more so for the 19 year old because it is just too cruelly soon.

I would imagine billionaires have an army of experts vetting stuff for them. So I am quite surprised that the OceanGate operation didn't raise enough alarm bells for them to not board the vessel.

Anyways, may be this incident might potentially change the way this industry is regulated and operated.

Originally Posted by mohansrides

Now coming to the ink online equating these guys to explorers and whatnot!! Really, what a load of utter garbage!! Explorers are pioneers who venture into the unknown to expand the cause of all mankind. Blowing a bunch of money to go and see a shipwreck (that has been studied a million times already) hardly qualifies as pioneering. Really, these 5 dudes aren't equal to Vasco da Gama or Christopher Columbus or any such person. These were rich and bored folk who made a reckless decision without understanding the value of life.

You might want to read how many lives were lost during the voyages/explorations of Vasco da Gama, Christopher Columbus or Captain Cook.

The violent and deadly impact on the OG residents of their “discovered new land” is at another level.

So I think the context is important and there’s no need to glorify some to crucify some others. I suppose they all just did what was the norm in their respective their lifetimes. Kings wanted to own new lands/subjects and billionaires want to see what other billionaires haven't seen. It is what it is.

Originally Posted by thanixravindran

PS: I am not going to argue on the objective and the aftermath of the 'expeditions' of Vasco da Gama or Christopher Columbus.

[adi.mariner]

An informative article regarding how the hull of the Titan was built. Credits to the respective authors/website.

https://www.drass.tech/2023/06/27/ti...es-of-failure/

[Gansan]

Originally Posted by kiku007

"Then I stepped back and gave them space to set [Suleman] up, because he really wanted to go," she said."[/i]

It is not just a matter of him wanting to go. The crux is the pages and pages of conditions and disclaimers and waivers he had to go through, and give "informed consent" by signing them. Was he qualified or considered old enough to do that?

If I was the father, those would have rung a bell to me and I would have stopped my son from entering come what may.