Titanic tourist submersible goes missing with search under way

[Pass2Run]

Here is James Cameron's movie, Deepsea Challenge. It talks about how a sphere is the most ideal shape for a submersible. This sphere shrinks 2 inches while under pressure at those depths. Crazy!

 

[Pass2Run]

How long do you guys think it will take before criminal charges are filed?

 

[VaqueroTD]

None of those things is like this thing. Not even in the same galaxy as this thing.

True dat.

I’ve done all 3 — Grand Canyon, Niagara Falls, and a Live Boys Game — and you would NEVER see me in a reduced cost private sub 2 miles under the ocean.

It needs to look like the Red October before I even consider stepping foot.

It’s one thing to do it as a military, scientific or exploration first.

But these billionaires who book these private enterprise short cut deep space or deep sea tourist trips must be chatting it up with this guy.

 

[Flamma]

Right, but did you watch the video I posted showing the testing of steel and carbon fiber drive shafts? The CF drive shaft withstood much more torque than the steel drive shaft despite the fact the CF shaft was significantly lighter in weight. It is not how the material fails, it is when the material fails that matters. Also, note the CF shaft did not fail at the connections to the metal end caps. The CF itself failed. Now torque is not the same as a compression force but it is still a good demonstration of the strength of CF.

Right. Compression force is going to be about the same as steel. For example, 5 inches of CF is similar to 5 inches of steel, just much lighter. Both carbon fiber and steel have moduli of elasticity upwards of 200 gigapascals. Making them equal in that regard.

 

[gtb1943]

How long do you guys think it will take before criminal charges are filed?

so you finally admit that your claim it was a PR stunt had no basis in fact and no evidence to support it?

 

[rags747]

Right. Compression force is going to be about the same as steel. For example, 5 inches of CF is similar to 5 inches of steel, just much lighter. Both carbon fiber and steel have moduli of elasticity upwards of 200 gigapascals. Making them equal in that regard.

I’m not following. Are you only talking about compression force? Fives inches of carbon Fibre is much stronger than five inches of steel and yes much lighter. Also carbon Fibre can reach upwards of 500 for elasticity while steel reaches low 200’s, high strength steel a little higher. Maybe I’m missing what you are saying.

 

[CalPolyTechnique]

Here is James Cameron's movie, Deepsea Challenge. It talks about how a sphere is the most ideal shape for a submersible. This sphere shrinks 2 inches while under pressure at those depths. Crazy!

Risen said he shrinks two inches when under intense pressure too.

 

[JackOfNoTrades]

Like everything, applications and uses are limited. Carbon fiber can be strong but not also suited to the repeated exposures of pressures 400x that of the surface of the earth.

James Cameron made it to deepest part of the earth and he’s still living. He didn’t use carbon fiber and has said it’s not suited for deep sea diving.

And we’re talking two different things when it comes to air travel versus underwater.

from what I've read, steel is a better material for applications where implosion is a risk and carbon fiber when explosion.

 

[gtb1943]

from what I've read, steel is a better material for applications where implosion is a risk and carbon fiber when explosion.

IF carbon fiber was all some here say it is, why is its applications still very limited? Its not that much more expensive than steel.

 

[Vtwin]

The carbon fiber hull and the view port did hold up on at least ten prior dives to the Titanic.

No consolation to the families who lost loved ones on the 11th dive but it's worth noting.

 

[gtb1943]

The carbon fiber hull and the view port did hold up on at least ten prior dives to the Titanic.

No consolation to the families who lost loved ones on the 11th dive but it's worth noting.

Are any of the commercial/professional submarines that do deep diving made of carbon fiber? IF this was the only one, maybe there is a reason....

 

[Vtwin]

Are any of the commercial/professional submarines that do deep diving made of carbon fiber? IF this was the only one, maybe there is a reason....

Ya think?

I was simply pointing out that the thing survived ten previous trips. Nothing more. Nothing less.

 

[rags747]

IF carbon fiber was all some here say it is, why is its applications still very limited? Its not that much more expensive than steel.

It’s not very limited in racing at all. It’s not very limited in scuba tanks, it’s not very limited in high end production cars, it is not very limited in automotive wheels. If you want low weight, high strength in the correct applications and high cost then Carbon Fibre is the material for you! Low weight and high strength in high end applications usually wins out vs heavy steel. Now, I said the correct applications.

 

[Flamma]

I’m not following. Are you only talking about compression force? Fives inches of carbon Fibre is much stronger than five inches of steel and yes much lighter. Also carbon Fibre can reach upwards of 500 for elasticity while steel reaches low 200’s, high strength steel a little higher. Maybe I’m missing what you are saying.

I was just going by what I read on the matter.

https://zoltek.com/carbon-fiber-vs-...deal for a number of high-stress applications.

From the link.....

"Wait, if both carbon fiber and steel have comparable moduli of elasticity, how can you say that carbon fiber is stronger?"

 

[rags747]

So that article states that carbon fiber is about 5x stronger than steel. If that is the case then you would not need 5 inches of carbon fiber to equal 5 inches of steel In strength, it should be much less. Anyway no big deal, I think we are beating a dead horse here. Thx…

 

[Pass2Run]

Risen said he shrinks two inches when under intense pressure too.

Ouch

 

[Creeper]

Right. Compression force is going to be about the same as steel. For example, 5 inches of CF is similar to 5 inches of steel, just much lighter. Both carbon fiber and steel have moduli of elasticity upwards of 200 gigapascals. Making them equal in that regard.

Which brings us back to design or fatigue. I would still like to learn more about CF fatigue, what causes it, how quickly it occurs, and what indications of fatigue can be inspected before failure.

 

[rags747]

Large pieces starting to be brought up, saw a couple of YouTube videos today. Will be interesting to see what’s what.

 

[Flamma]

Which brings us back to design or fatigue. I would still like to learn more about CF fatigue, what causes it, how quickly it occurs, and what indications of fatigue can be inspected before failure.

From everything I've watched, that's not something easy to do. I guess someone would have to take the time and money to do testing in a pressure chamber.

I also wonder why they chose a 5" hull. If it's so much lighter than steel, why not beef it up a little. I also think it was wound in a straight up to down pattern as opposed to the diamond shape pattern I see sometimes.

I believe the one that went down to the bottom of challenger deep was only 2.5 inches of steel. But i don't think it was a tube.

 

[Creeper]

From everything I've watched, that's not something easy to do. I guess someone would have to take the time and money to do testing in a pressure chamber.

I also wonder why they chose a 5" hull. If it's so much lighter than steel, why not beef it up a little. I also think it was wound in a straight up to down pattern as opposed to the diamond shape pattern I see sometimes.

I believe the one that went down to the bottom of challenger deep was only 2.5 inches of steel. But i don't think it was a tube.

It might be conjecture on someone's part but I read it was designed the way it was to fit 5 paying passengers. But still, if they wanted to build a tube they could have used a bulkhead to strengthen the sides, but that too would add weight and take up room in the passenger compartment.