Titantic...

[JohnRoberts]

anyone with on topic comments?

JR

 

[sahib]

As you have also mentioned, the owner or the owners of this company was/were taking a lot of risk, and there is no doubt that what happened was just a matter of time. We'll hear the full story soon.

 

[pucho812]

news reports say that a debris field has been found, so RIP...

JR

Confirmed. News is reporting implosion of the sub and all 5 souls dead.
What a horrible way to go, I wouldn’t wish it on my worst enemies.

 

[Michael Tibes]

RIP

This is horrible - though it is beyond my understanding why anyone might want to dive down there as entertainment. It seems like it had been known that the ship was 'experimental' and severe problems occurred on previous dives.
I used to ride motorcycle, I understand that thrill, I can understand airplane pioneers, astronauts and and other experimenters which died and whose deaths still were meaningful for mankind because their actions were bringing knowledge into the world. But I do not understand why people might want to dive that deep to the wreck of Titanic. The place is already a mass grave and the Titanic a symbol for human arrogance. Shouldn't that be enough?

 

[sahib]

I just hope no one’s actually calling the millionaires, horrible.....

RIP to them all.

To eliminate the risk of misunderstanding I have changed it to "irrelevant" and I hope you know what I meant.

However, I join you on RIP.

 

[boji]

RIP brave aquanauts. If implosion occurred, my layman's guess it began along some contour of the vessel that was not pill-shaped.

 

[JohnRoberts]

The bodies are already cold, but I will wait for a respectful technical post mortem.

Back in the 60's I worked on a deep submergence project that was only targeting 5,000' depth.

JR

 

[pucho812]

If implosion occurred, they may have been dead for days and we just found debris today.
We as humans know way more about what goes on in our skies then what goes on in the deepest parts of the ocean.

 

[AnalogPackrat]

Likely the USN knew if there was an implosion. We have a large array of hydrophones all over the world's oceans. It's a shame this Stockton Rush character let his misguided social agenda affect his hiring decisions. It seems apparent that the design/implementation/operation were all seriously flawed.

https://www.livescience.com/planet-...to-catastrophic-implosion-us-coast-guard-says

 

[pucho812]

Likely the USN knew if there was an implosion. We have a large array of hydrophones all over the world's oceans. It's a shame this Stockton Rush character let his misguided social agenda affect his hiring decisions. It seems apparent that the design/implementation/operation were all seriously flawed.

https://www.livescience.com/planet-...to-catastrophic-implosion-us-coast-guard-says

They fired the whistle blower who addressed concerns on this.

 

[living sounds]

This is horrible - though it is beyond my understanding why anyone might want to dive down there as entertainment.

Yes, we have great VR these days and the kind of money they payed would have bought a very nice hydraulic simulator.

Not the worst way to go though, from what I understand death is practically instantenous at those depths...

 

[user 37518]

This is a tragedy, we are talking about being inside a soda can whilst it is being crushed. They said it was instantaneous, I pray it was. I feel truly shocked about these poor souls. There was a 19 year old kid in there. This is truly sad.

Requiem aeternam dona eis, Domine, et lux perpetua luceat eis. Requiescant in Pace. Amen.

 

[pucho812]

hopefully they didn’t drown. No joke here I mean that. It takes a human 10 -12 minutes to die from drowning. Implosion of the sub seems like it would be faster.

 

[user 37518]

hopefully they didn’t drown. No joke here I mean that. It takes a human 10 -12 minutes to die from drowning. Implosion of the sub seems like it would be faster.

I also hope there wasn't much of a previous warning, rather than it just happened and they didn't even realize it.

 

[sahib]

RIP

This is horrible - though it is beyond my understanding why anyone might want to dive down there as entertainment.......
........ But I do not understand why people might want to dive that deep to the wreck of Titanic. The place is already a mass grave......

Although, it does not take away the tragic side of it, I agree with you on this. Pucho said it earlier on. Don't disturb the dead. Now another five added.

Apparently the boy was hesitant to take part, and I would imagine his dad wanted him to have this experience with good intentions too. But what an irresponsible thing to do to take a risk of this magnitude. I have a son of 22 and I am often on a knife edge for the risks that he takes, which in comparison to this are probably the safest things to do.

I personally never had the desire to do things like visiting the jungles or climbing the mountains, let alone diving to graveyards. The biggest risk I take is probably crossing the pedestrian crossing at red light.

 

[soliloqueen]

Carbon fiber?? For a compressive load? The more I hear about it the crazier it gets. It was so sure to fail at depth that the conspiracy theorist in me almost wonders if this was some kind of extremely roundabout murder. Doubly so when they fired the dude that pointed this out immediately and buried his report. This isn't my subfield of engineering but from what I know it's difficult to imagine a worse design for a submarine.

 

[Spiritworks]

hopefully they didn’t drown. No joke here I mean that. It takes a human 10 -12 minutes to die from drowning. Implosion of the sub seems like it would be faster.

Implosion is instant death, like stepping on an ant. So fast they didn't know what hit them, with no idea it was about to occur.

 

[JohnRoberts]

Carbon fiber?? For a compressive load? The more I hear about it the crazier it gets. It was so sure to fail at depth that the conspiracy theorist in me almost wonders if this was some kind of extremely roundabout murder. Doubly so when they fired the dude that pointed this out immediately and buried his report. This isn't my subfield of engineering but from what I know it's difficult to imagine a worse design for a submarine.

+1 An obvious question...(not the suicide/murder part). Submarine hulls are generally made from strong steel, or titanium. I think the front nose piece with viewing port of that OceanGate vessel was made from titanium. Which is probably more expensive than carbon fiber.

Real military submarine hulls are over-designed to survive nearby explosions. Typical test dive depths are around 500 meters, while actual design depths could be 2x that for safety and are routinely classified.

Carbon fiber is strong and lightweight but can be brittle. It is a little too easy to second guess this choice for a submarine hull in hindsight. Carbon fiber is already used in aircraft, space craft, sail boats, and race cars for the high strength to low weight characteristic.

JR

[edit- the news speculation is already shifting to that they were obviously dead within a couple hours of initiating the dive. The Navy heard the sound of an implosion and reported it to the coast guard. So we have likely suffered days of drama for no good reason. === If this same hull made multiple deep dives there is probably a fatigue mechanism where microscopic breaks in the carbon fibers accumulate over time (my personal speculation). /edit]

 

[AnalogPackrat]

+1 An obvious question...(not the suicide/murder part). Submarine hulls are generally made from strong steel, or titanium. I think the front nose piece with viewing port of that OceanGate vessel was made from titanium. Which is probably more expensive than carbon fiber.

There were reports that the manufacturer of the view port would not rate it for use beyond 4000' (IIRC) depth. The videos showing how the nose cone was attached to the CF capsule do not instill confidence. Engine head gaskets are secured better than that.

Real military submarine hulls are over-designed to survive nearby explosions. Typical test dive depths are around 500 meters, while actual design depths could be 2x that for safety and are routinely classified.

Carbon fiber is strong and lightweight but can be brittle. It is a little too easy to second guess this choice for a submarine hull in hindsight. Carbon fiber is already used in aircraft, space craft, sail boats, and race cars for the high strength to low weight characteristic.

As noted earlier, CF is great in tension, not compression (where the epoxy resin ends up taking the load). That's why it is used in aircraft, spacecraft, hydrogen storage tanks, and other applications where the vessel is positively pressurized. This is what happens when inexperienced engineers use "aerospace principles" to guide the design of a very deep water submarine.

JR

[edit- the news speculation is already shifting to that they were obviously dead within a couple hours of initiating the dive. The Navy heard the sound of an implosion and reported it to the coast guard. So we have likely suffered days of drama for no good reason. === If this same hull made multiple deep dives there is probably a fatigue mechanism where microscopic breaks in the carbon fibers accumulate over time (my personal speculation). /edit]

CF develops cracks and fractures in the resin. Not always easily detected and not easily repaired if detected. I'd guess the weak point is where the nose cone is joined to the monolithic CF capsule. It has large diameter there and a weakly secured circumferential joint that undergoes stress twice each time the sub is used (the nose cone is the entry and exit for passengers and is removed/reattached).

 

[JohnRoberts]

Furthermore, it was reported that the carbon fibers’ axial compressive strength is only 10%–60% of their tensile strength and their transverse compressive strength is 12%–20% of axial compressive strength. Carbon fibers have a lower compressive strength of 1–3 GPa compared to inorganic fibers, however, it is still higher than polymeric fibers [13,14].

Some disadvantages of carbon fibers include their low shock resistance (owing to their high fragility and rigidity),

I know I don't know...

Back in the 60s I had a summer job that involved making fiberglas water barrel scoops (for ocean water collection by oceanographic research ships). Did I mention I really hate fiberglass?

JR

 

[sahib]

CF develops cracks and fractures in the resin. Not always easily detected.......

A professor of (I think) mechanical engineering emphasised the same on the TV.

 

[user 37518]

Carbon fiber?? For a compressive load? The more I hear about it the crazier it gets. It was so sure to fail at depth that the conspiracy theorist in me almost wonders if this was some kind of extremely roundabout murder. Doubly so when they fired the dude that pointed this out immediately and buried his report. This isn't my subfield of engineering but from what I know it's difficult to imagine a worse design for a submarine.

That is what impressed me most. They said that no submarines have been made out of carbon fiber, since it hasn't been tested at such high pressures. Yet, these people were so sure of their engineering skills that even the company owner went in there in a never tested, completely experimental and unorthodox sub, without even questioning it. I really distrust those people who never question themselves whether they can be wrong.

 

[pucho812]

Did the company ever do unmanned testing?