Titanic tourist submersible goes missing with search under way

[gtb1943]

You know, I wonder who would have gotten all the glory if it was something like the U.S. Coast Guard setting up a rescue mission to take the heat off of them for not assisting with this one. Meanwhile . . . the U.S. Coast Guard gets to play the hero, momentarily, only to have to play this whole thing fizz out, even when they knew there was a blast at the same moment they lost communication. So, they just stood up there knowing what happened. The one reporter who asked "what level of hope can we give the families," and he lost his poker face or baseline, and at that point, I was pretty sure they knew something.

Of course, we know our military is tracking every inch of every sea. We know what is out there.

Every inch of every sea?

Do you really believe that?

 

[rags747]

It's amazing how much lighter carbon fiber is compared to steel. Roughly around 5X. That's why they consider it 5X stronger. Because Steel is much denser but isn't any stronger. From what I understand, the same amount of steel as carbon fiber are equal in strength.

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

 

[Vtwin]

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

When CF mountain bikes came out they became very popular entirely because they were so lightweight. Things shifted back towards steel alloy frames a bit when the CF forks started to fail suddenly and completely, and frames couldn't be trusted or tested after a good crash or two.

 

[Runwildboys]

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

I believe Flamma is saying the same amount of each material per volume, not weight.

 

[Roadtrip635]

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

I think it's used most often to reduce weight which will increase speed or decrease amount of fuel used. Carbon fiber is just as strong or stronger than most steels or alloys, but the tradeoff is durability.

 

[Flamma]

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

I agree 100%. My mistake in the way I worded it. I didn't mean the same weight. I meant a 5 inch thick piece of steel is going to be just as strong as a 5 inch thick piece of carbon fiber. Just 5X heavier.

 

[rags747]

I think it's used most often to reduce weight which will increase speed or decrease amount of fuel used. Carbon fiber is just as strong or stronger than most steels or alloys, but the tradeoff is durability.

Agreed, exactly why I pointed out earlier that it will be interesting to see the long term effects on the airline industry. How will the carbon Fibre hold up to years and years of pressurizing and depressurizing. Aluminum we know can develop stress cracks after years of this, I believe there have already been some minor issues with carbon Fibre delaminating in certain areas due to water etc. Time will tell.

 

[Flamma]

I think it's used most often to reduce weight which will increase speed or decrease amount of fuel used. Carbon fiber is just as strong or stronger than most steels or alloys, but the tradeoff is durability.

Most of the time carbon fiber or composite is used is to reduce weight. Like a steel toe boot as opposed to composite. One isn't any stronger than the other, but the steel toe is 5x heavier. That's what makes carbon fiber stronger. Much less of it for the same strength.

 

[Roadtrip635]

Agreed, exactly why I pointed out earlier that it will be interesting to see the long term effects on the airline industry. How will the carbon Fibre hold up to years and years of pressurizing and depressurizing. Aluminum we know can develop stress cracks after years of this, I believe there have already been some minor issues with carbon Fibre delaminating in certain areas due to water etc. Time will tell.

For limited use or timetable for scheduled replacement, carbon fiber is fine. For extended use being exposed to constant forces, pressure, heat, cold, moisture etc., I don't think I would feel any safer. When carbon fiber fails, it fails spectacularly. Stronger does not necessarily mean safer, it just seems that there are more variables that will adversely affect it.

 

[Hoofbite]

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.

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.

 

[Tabascocat]

Not really. Five pounds of carbon Fibre vs five pounds of steel the five pounds of carbon Fibre would be significantly stronger. If you think about it why would Boeing, Airbus, high end car manufacturers use carbon Fibre? They can reduce weight greatly while improving strength although costs go up substantially. No airline would replace an aluminum airframe with carbon Fibre if the resulting plane weighed the same, same with car manufacturers. Dive tanks are now made out of carbon Fibre, I believe due to lightness. Any dive pros here?

I’m a kinda retired scuba instructor, haven’t taught a class in years though. CF tanks have their uses because they are lightweight and also easier for those with back pains. I only use that tank side mount. I wouldn’t recommend a CF tank for any other type of diving except for recreational use only…..the basic open-water diver. They are also used frequently in sump diving.

But, they are quite a bit more expensive, fragile and if salt water gets in the resin matrix….the tank is all but done. They have a shelf-life. They are much better suited for freshwater dives and fireman tanks. Not to mention, you have to add more lead due to buoyancy issues.

 

[triplets_93]

 

[Creeper]

A lot of good discussion around carbon fiber but I wonder how much we really know. From what I have read, carbon fiber is stronger and more durable than steel. And not just by equivalent weights. But it is also less dense (hence the lighter weight).

Watch this video:

It is hard to imagine a drive shaft made of such a light material being stronger than steel, especially under torque, but it is. Of course the Titan was not dealing with torque, but still the carbon fiber is incredibly strong.

But what does this mean? There has to be more to it. Was the shape of the Titan a problem? A ball would be stronger than a tube, wouldn't it? What about the possibility the Titan hit something and suffered damage to the hull before the implosion? My physics is a little rusty but what about the effect of the density of the water on the carbon fiber tube? CF has a high tensile strength but its compression strength can be as little as 10% of its tensile strength.

I have to believe people a lot smarter than me looked at all this before they dropped that thing in the water but I am very curious. I wonder if they will attempt to recover the pressure chamber to see if they can figure out what happened.

 

[Tabascocat]

A lot of good discussion around carbon fiber but I wonder how much we really know. From what I have read, carbon fiber is stronger and more durable than steel. And not just by equivalent weights. But it is also less dense (hence the lighter weight).

Watch this video:

It is hard to imagine a drive shaft made of such a light material being stronger than steel, especially under torque, but it is. Of course the Titan was not dealing with torque, but still the carbon fiber is incredibly strong.

But what does this mean? There has to be more to it. Was the shape of the Titan a problem? A ball would be stronger than a tube, wouldn't it? What about the possibility the Titan hit something and suffered damage to the hull before the implosion? My physics is a little rusty but what about the effect of the density of the water on the carbon fiber tube? CF has a high tensile strength but its compression strength can be as little as 10% of its tensile strength.

I have to believe people a lot smarter than me looked at all this before they dropped that thing in the water but I am very curious. I wonder if they will attempt to recover the pressure chamber to see if they can figure out what happened.

Yes, it was a poor design. A round, spherical shape is best. You want that deep ocean pressure hitting every square inch equally. Imagine a pringle can, if you squeeze the tube, what happens? The lid pops off.

 

[Creeper]

Yes, it was a poor design. A round, spherical shape is best. You want that deep ocean pressure hitting every square inch equally. Imagine a pringle can, if you squeeze the tube, what happens? The lid pops off.

That was my point. Submarines are tubes as well but they have bulkheads placed at specific intervals to reinforce the hull to allow it to dive deeper. I don't recall seeing any bulkheads in the Titan tube. Perhaps they thought it would not need any because the tube itself was not that long. I would still love to see them recover the pressure chamber to figure out what went wrong.

 

[Tabascocat]

That was my point. Submarines are tubes as well but they have bulkheads placed at specific intervals to reinforce the hull to allow it to dive deeper. I don't recall seeing any bulkheads in the Titan tube. Perhaps they thought it would not need any because the tube itself was not that long. I would still love to see them recover the pressure chamber to figure out what went wrong.

Military submarines don’t go to those same depths as a submersible. It would face the same fate if so.

 

[gtb1943]

Military submarines don’t go to those same depths as a submersible. It would face the same fate if so.

They don't because militarily there is no advantage in going anywhere near that deep. IF there was they would be designing them to do it.

 

[rags747]

I believe the current highest rated sub for depth is Russian. Ty…

 

[Tabascocat]

They don't because militarily there is no advantage in going anywhere near that deep. IF there was they would be designing them to do it.

Of course, if they wanted to go into the abyss, it would be a completely different design. That was my point, tubes have no business going miles down.

 

[triplets_93]