Titanic tourist submersible goes missing with search under way

[Tabascocat]

Just as an fyi the Airbus A350 and the Boeing 787 Dreamliner are made mostly of Carbon Fibre as well. Carbon Fibre is much stronger than steel, I believe 3X and about 70% lighter than steel. The test with these planes will be how the Carbon Fibre holds up under long term pressurization cycles. Carbon Fibre is much more expensive than steel but people love it for its light weight and strength.

I have a car that has a complete Carbon Fibre tub, Rigidity, Strength and Weight are beautiful but when involved in an accident the Carbon Fibre tends to shatter and rip usually causing the car to be totaled as its tough to determine how much of the tub has actually been stressed or damaged Plus there are not too many firms out there in the Carbon Fibre repair business.

Also the Titan made 6 dives to the Titanic in 21 and 7 dives to the Titanic in 22. Thats 13 heavy duty pressure cycles on that Carbon Fibre hull, exactly why I said that the airline industry is very interested to see how their planes hold up long term. At this point I think it’s undetermined.

There is a huge difference pressurizing airplanes and the crushing force of the deep sea. It will take thousands of flights to test that theory compared to a few for a carbon fiber submersible. I think it is great for planes, submersibles….not so much.

 

[Creeper]

Didn't this sub make this trip before? How was it tested to determine it could withstand the depths they took it down to? I also wonder if the problem was with the way they closed the capsule up by bolting it together from the outside. If those bolts were not tight enough wouldn't it potentially leak at very high pressures? And even a small leak would compromise the strength of the hull, wouldn't it? I saw a video fo them tightening the bolts with regular wrenches, not even torque wrenches. How would they know how tight those bolts were?

 

[CalPolyTechnique]

M

..does carbon fiber wear out? You know, like mileage on a car or your old T-shirt.

Depending on its use it can degrade and splinter on the micro level which under the insane load of being under thousands of feet of water can cause macro catastrophic failure.

 

[rags747]

Didn't this sub make this trip before? How was it tested to determine it could withstand the depths they took it down to? I also wonder if the problem was with the way they closed the capsule up by bolting it together from the outside. If those bolts were not tight enough wouldn't it potentially leak at very high pressures? And even a small leak would compromise the strength of the hull, wouldn't it? I saw a video fo them tightening the bolts with regular wrenches, not even torque wrenches. How would they know how tight those bolts were?

6 trips to Titanic in 21 and 7 trips in 22.

 

[gtb1943]

The Titanic don't play around.

Supposedly the pilot of the sub was a descendant of a couple from the Titanic that survived; that is what I read somewhere this morning.

It reached out and took one to make up for those it did not get the first time around.

 

[Montanalo]

Carbon fiber is a pretty interesting material in terms of its properties: very high tensile strength, light weight, non-corrosive.

I've used carbon fiber scuba tanks pressured to 4,500 psi (the standard aluminum tank is typically capped at about 3,200 psi working pressure). Much lighter than comparable steel tanks. So, carbon fiber can be designed for high pressure environments.

I am not a material scientist but, if I had to venture a guess, I would think the implosion probably resulted from a flaw in the original manufacturing of the carbon fibers. Its a complicated process and, I would imagine difficult to ensure uniform properties throughout the sub's shell.

 

[gtb1943]

Carbon fiber is a pretty interesting material in terms of its properties: very high tensile strength, light weight, non-corrosive.

I've used carbon fiber scuba tanks pressured to 4,500 psi (the standard aluminum tank is typically capped at about 3,200 psi working pressure). Much lighter than comparable steel tanks. So, carbon fiber can be designed for high pressure environments.

I am not a material scientist but, if I had to venture a guess, I would think the implosion probably resulted from a flaw in the original manufacturing of the carbon fibers. Its a complicated process and, I would imagine difficult to ensure uniform properties throughout the sub's shell.

It will probably never be truly isolated what went wrong. We know there is metal fatigue; maybe there is a version of carbon fiber fatigue. Its good under huge pressure for a certain time or maybe a certain number of pressurizations and depessureizations and then it starts to give. It took a long time to figure out metal fatigue; decades.

 

[Runwildboys]

Carbon fiber is a pretty interesting material in terms of its properties: very high tensile strength, light weight, non-corrosive.

I've used carbon fiber scuba tanks pressured to 4,500 psi (the standard aluminum tank is typically capped at about 3,200 psi working pressure). Much lighter than comparable steel tanks. So, carbon fiber can be designed for high pressure environments.

I am not a material scientist but, if I had to venture a guess, I would think the implosion probably resulted from a flaw in the original manufacturing of the carbon fibers. Its a complicated process and, I would imagine difficult to ensure uniform properties throughout the sub's shell.

I wonder if the problem could be with the connection (joints) between the carbon fiber parts and any metal parts.

 

[Rockport]

Just as an fyi the Airbus A350 and the Boeing 787 Dreamliner are made mostly of Carbon Fibre as well. Carbon Fibre is much stronger than steel, I believe 3X and about 70% lighter than steel. The test with these planes will be how the Carbon Fibre holds up under long term pressurization cycles. Carbon Fibre is much more expensive than steel but people love it for its light weight and strength.

I have a car that has a complete Carbon Fibre tub, Rigidity, Strength and Weight are beautiful but when involved in an accident the Carbon Fibre tends to shatter and rip usually causing the car to be totaled as its tough to determine how much of the tub has actually been stressed or damaged Plus there are not too many firms out there in the Carbon Fibre repair business.

Also the Titan made 6 dives to the Titanic in 21 and 7 dives to the Titanic in 22. Thats 13 heavy duty pressure cycles on that Carbon Fibre hull, exactly why I said that the airline industry is very interested to see how their planes hold up long term. At this point I think it’s undetermined.

Good stuff.

 

[jsb357]

https://sanantonio.craigslist.org/boa/d/san-antonio-homemade-submarine-project/7635638508.html

someone getting out of the sub business

 

[Vtwin]

A laminate, wrapped, cylinder structure is going to be far more susceptible to implosion from external forces than from explosion from internal forces.

The dissimilar materials joined together with another dissimilar material is a major fail point.

If I was watching them build that, even an uneducated simpleton like me would have been asking questions about the science and testing behind that Mickey Mouse construction.

And trust me, I do have some experience in constructing some Micky Mouse contraptions and learning about where and how they fail.

 

[triplets_93]

 

[Rockport]

A laminate, wrapped, cylinder structure is going to be far more susceptible to implosion from external forces than from explosion from internal forces.

The dissimilar materials joined together with another dissimilar material is a major fail point.

If I was watching them build that, even an uneducated simpleton like me would have been asking questions about the science and testing behind that Mickey Mouse construction.

And trust me, I do have some experience in constructing some Micky Mouse contraptions and learning about where and how they fail.

I trust you.

 

[SlammedZero]

I wonder if the problem could be with the connection (joints) between the carbon fiber parts and any metal parts.

This was my wondering as well. I understand carbon fiber can be quite capable, but I was thinking about possible connection points that could have resulted in failing under the water pressure, like the viewport.

 

[rags747]

Supposedly the pilot of the sub was a descendant of a couple from the Titanic that survived; that is what I read somewhere this morning.

It reached out and took one to make up for those it did not get the first time around.

His wife is the descendant. He has some pretty heavy duty lineage as well, I believe two of his relatives signed the US Constitution plus there is some pretty heavy duty money on his side of the family, something like that.

 

[rags747]

A laminate, wrapped, cylinder structure is going to be far more susceptible to implosion from external forces than from explosion from internal forces.

The dissimilar materials joined together with another dissimilar material is a major fail point.

If I was watching them build that, even an uneducated simpleton like me would have been asking questions about the science and testing behind that Mickey Mouse construction.

And trust me, I do have some experience in constructing some Micky Mouse contraptions and learning about where and how they fail.

Pretty much what James Cameron says in the below. He also says that mating the carbon fibre to the two titanium end caps was not a good way to go about it. He mentioned that he got word early on I think on Monday that the sub was 200 meters from the ocean floor, radioed to the support ship that they were releasing their ballast so That they would begin the journey back up. Cameron says that this indicates that the captain had probably been alerted to the problem via the sensors that were supposed to be the early warning sign of fatigue of the shell. Can only imagine the noises of creaking and groaning that were being heard within that ship. If so absolute shear terror, RIP.

 

[rags747]

https://sanantonio.craigslist.org/boa/d/san-antonio-homemade-submarine-project/7635638508.html

someone getting out of the sub business

A true Rube Goldberg contraption! He did happen to re-weld some of the seams due to rust, are you freaking kidding me?! I would be afraid to take that down in the deep end of my pool let alone open waters.

 

[gtb1943]

Nothing of worth came about in the whole sad enterprise.

supposedly some were calling them pioneers and explorers; what a joke. A very sad joke.

A con man and his marks is more the way I see it.

 

[triplets_93]

 

[Vtwin]

Pretty much what James Cameron says in the below. He also says that mating the carbon fibre to the two titanium end caps was not a good way to go about it. He mentioned that he got word early on I think on Monday that the sub was 200 meters from the ocean floor, radioed to the support ship that they were releasing their ballast so That they would begin the journey back up. Cameron says that this indicates that the captain had probably been alerted to the problem via the sensors that were supposed to be the early warning sign of fatigue of the shell. Can only imagine the noises of creaking and groaning that were being heard within that ship. If so absolute shear terror, RIP.

I didn't know they made it that far and decided to abort. The emotions must have been off the charts. Russian roulette style off the charts.