Lost Submersible

[railfancwb]

May have imploded before people started looking for it, thus tge noise may not have been noticed.

Believe the guy of “old white men” remark was on the vehicle. 

[M&P15T]

I would assume they knew about the implosion, and kept operating like it was a search and rescue to give the USCG a publicity push.

[jmohme]

1 hour ago, M&P15T said:

There's carbon fiber, and then there's carbon fiber composites like your fishing rod. My understanding is that the material used to make the central section tube of that POS would just shatter, and can't sustain repeated dives to depth, as it's pure carbon fiber.

And like your fishing pole, the 787 uses carbon re-enforced plastics, not pure carbon fiber. 

"In total each Dreamliner contains about 70,000 pounds (33 tons) of carbon fiber reinforced plastic - of which about 45,000 (20 tons) pounds is carbon fiber." There's no pure CF used in the construction of a 787, just composites. And it's only 33 tons of composites out of a total weight of around 242 tons.

So, no it's not "made of carbon fiber". 

 

you are correct in that there is no pure carbon fiber used in any construction. Pure CF is just what the name says. It is a fiber not unlike fiberglass insulation.

The panels used in aircraft are mostly epoxy impregnated carbon fiber sheets that are molded and then thermally set in ovens. I don't know of any single piece constructions using this material. Most are done in sections and bonded with special adhesives while being held together with temporary fasteners when this sets. I suppose in some very high stress applications, permanent fasters are used with the bonding adhesives.

In a submersible at those depths, I would guess that it would only take one of these bonded joints to fail and then cascade into a total structural failure.

Yes, most carbon fiber composite and plastics are strong, light, and flexible, but that is at atmospheric pressures, not the pressures under 12,000 feet of ocean.

I would imagine that their end was quick anyway.

[Eric]

13 minutes ago, railfancwb said:

May have imploded before people started looking for it, thus tge noise may not have been noticed.

Believe the guy of “old white men” remark was on the vehicle. 

I guess you are right. They were listening for its regular pings at fifteen minute intervals though, so someone was manning the sonar equipment. I wonder if they kept recordings of the sonar, communications and other telemetry data they may have had during the dive?

[minervadoe]

I wonder if the people on the sub even lived long enough to know something went wrong. 

Here's what we learned from the US Coast Guard's press conference:

• US Coast Guard officials have said the debris findings were the result of a "catastrophic implosion" of the vessel carrying the five passengers
• The site of the fatal accident was believed to be 1,600ft (487m) off the bow of the Titanic wreck
• Five major pieces were discovered amid the debris around the Titanic site. Among them, a nose cone, outside the pressure hull, and a larger debris field
• Rear Adm Mauger said he cannot confirm whether or not the US Coast Guard will be able to locate the victims' bodies. "This is an incredibly unforgiving environment," he said
• There did not appear to be any connection between the noises that have been detected since Wednesday to the Titan sub, he said
• The US Coast Guard said it will continue to investigate the site of the debris field. Rear Adm Mauger said right now there are nine vessels, medical personnel and technicians on the scene
• The US Coast Guard will begin to demobilise personnel over the next 24 hours

[tous]

And now I am hearing supposedly professional journalists refer to the Titanic as the USS Titanic.

You think the British will be angry that we just swiped their ship?

 

[Eric]

5 minutes ago, tous said:

And now I am hearing supposedly professional journalists refer to the Titanic as the USS Titanic.

You think the British will be angry that we just swiped their ship?

 

It was a British-registered, Irish-built, American-owned vessel. That ship had some identity issues. The poor thing didn't know whether to build an empire, beat the hell out of an empire or get drunk and think about it.

[tous]

I think that  it was owned by White Star Lines, no?

Still British.

Which meant that it had Lucas electrics.

[Eric]

5 minutes ago, tous said:

I think that  it was owned by White Star Lines, no?

Still British.

Which meant that it had Lucas electrics.

White Star Lines was owned by an American company. JP Morgan was a major stockholder.

[Eric]

9 minutes ago, tous said:

I think that  it was owned by White Star Lines, no?

Still British.

Which meant that it had Lucas electrics.

I had to look it up. I read about this years ago, but forgot the company name. The International Mercantile Marine Company, bankrolled and run by JP Morgan owned The Whitestar Line and many other transatlantic shipping companies. He was attempting to monopolize Atlantic shipping.

[Paul53]

It's the carburetor.

[Paul53]

39 minutes ago, tous said:

And now I am hearing supposedly professional journalists refer to the Titanic as the USS Titanic.

You think the British will be angry that we just swiped their ship?

 

Probably glad to be rid of it!

[Batesmotel]

At those depths a Catastrophic Failure means water exploded into the structure at three times the speed of sound. They never knew it happened. 

[ChuteTheMall]

[Fog]

3 hours ago, M&P15T said:

There's carbon fiber, and then there's carbon fiber composites like your fishing rod. My understanding is that the material used to make the central section tube of that POS would just shatter, and can't sustain repeated dives to depth, as it's pure carbon fiber.

And like your fishing pole, the 787 uses carbon re-enforced plastics, not pure carbon fiber. 

"In total each Dreamliner contains about 70,000 pounds (33 tons) of carbon fiber reinforced plastic - of which about 45,000 (20 tons) pounds is carbon fiber." There's no pure CF used in the construction of a 787, just composites. And it's only 33 tons of composites out of a total weight of around 242 tons.

So, no it's not "made of carbon fiber". 

 

The pictures of Titan being built clearly show composite construction. There just is no other way to build it at that scale. Even carbon rods, used in industrial processes, are not "pure carbon", they have additives to give them usable properties for the intended application.

Carbon fiber is used in pressure vessels all the time. Dive tanks and SCBA tanks use carbon fiber and are rated and used to 4500psi and in special applications to 6000psi. The depth the Titanic sits at is roughly 12,500' so under 5,500 psi 

I am not claiming the little sub was well built, or a good idea. But blaming it on carbon fiber, or claiming carbon fiber can't flex or withstand pressure is just ignorant. 

The very wreck they were diving to see sank because they didn't understand steel alloys and what worked best for ships hulls, and steel was hardly a new shipbuilding material at the time.

Lots of boats, planes, even heavy mining machines are using carbon fiber. OTR trucks are being tested with it in critical structure parts. Cars are using it more and more. Only thing holding it back is development and production costs are higher than most metals so there is limited economic incentive.

[M&P15T]

7 minutes ago, Fog said:

The pictures of Titan being built clearly show composite construction. There just is no other way to build it at that scale. Even carbon rods, used in industrial processes, are not "pure carbon", they have additives to give them usable properties for the intended application.

Carbon fiber is used in pressure vessels all the time. Dive tanks and SCBA tanks use carbon fiber and are rated and used to 4500psi and in special applications to 6000psi. The depth the Titanic sits at is roughly 12,500' so under 5,500 psi 

I am not claiming the little sub was well built, or a good idea. But blaming it on carbon fiber, or claiming carbon fiber can't flex or withstand pressure is just ignorant. 

The very wreck they were diving to see sank because they didn't understand steel alloys and what worked best for ships hulls, and steel was hardly a new shipbuilding material at the time.

Lots of boats, planes, even heavy mining machines are using carbon fiber. OTR trucks are being tested with it in critical structure parts. Cars are using it more and more. Only thing holding it back is development and production costs are higher than most metals so there is limited economic incentive.

I'm not really interested in debating this, because there isn't one. 

There is carbon fiber, and there is a whole lot of other composites, and you don't seem to understand that. Your example of SCUBA tanks is completely incorrect, as they use carbon fiber reinforced polymer, or CFRP. That is NOT the same thing as carbon fiber. 

Please, just drop this. 

[tous]

Thank you.

We built the F/A-18 with a lot of composite (carbon fiber) components, but relied on metals for critical systems, mainly aluminum alloys and titanium.

The benefit of carbon fiber composites is that they are very strong, easy to calculate reaction to forces and light-weight

Significant  weaknesses of carbon fiber composites is that they are not as flexible and do not fail gradually like  metals do.

Instead of a stress crack developing over years leading to failure, carbon fiber composites fail catastrophically; one minute they're fine, the next, catastrophic failure.

And there is really no good way inspect them to detect signs of impending failure.

 

Great material, if used intelligently.

[Eric]

54 minutes ago, tous said:

Thank you.

We built the F/A-18 with a lot of composite (carbon fiber) components, but relied on metals for critical systems, mainly aluminum alloys and titanium.

The benefit of carbon fiber composites is that they are very strong, easy to calculate reaction to forces and light-weight

Significant  weaknesses of carbon fiber composites is that they are not as flexible and do not fail gradually like  metals do.

Instead of a stress crack developing over years leading to failure, carbon fiber composites fail catastrophically; one minute they're fine, the next, catastrophic failure.

And there is really no good way inspect them to detect signs of impending failure.

 

Great material, if used intelligently.

On a tangent, a supercar maker who makes unusual, but very interesting cars is Pagani. The make the Huayra and some other models out of a composite called carbotanium. It is comprised of titanium wire that is plated with platinum, heated to like 500 degrees celsius, coated with a primer, then an adhesive and then coated with carbon. I am a little fuzzy on the whole process, but I assume this is done the the titanium wire first and then it is woven with carbon fiber into sheets. It is supposed to be light, strong as hell, with superior elasticity and heat resistance. It sounds really complicated to make and therefore very expensive. I wonder if it is truly a superior enough material to justify the added cost, or if it is just a cool selling point for companies like Pagani to tout?

 

[Batesmotel]

Now they are calling the passengers “Heroes” and “True Explorers”.

B.S.  They were rich, thrill seeking tourists. Fine. If rich people want to go see and do things I’m all for it. But they were not exploring anything. Other than the cost and danger, it was no more of an expedition than going to a museum.

Bob Ballard was an explorer when he found the site in 1985. And even then that was an actually covert operation to find a lost submarine.

[geeorge]

I wonder if the passengers bought the insurance for the trip like you used to buy flight insurance at the airport

[Batesmotel]

10 minutes ago, geeorge said:

I wonder if the passengers bought the insurance for the trip like you used to buy flight insurance at the airport

Don’t know but I doubt it’s offered on high risk trips like that.

A friend was a dive master on Grand Cayman Island. Some of the dive spots including all cave and blue hole dives voided insurance. 

[tous]

48 minutes ago, Eric said:

... It sounds really complicated to make and therefore very expensive. I wonder if it is truly a superior enough material to justify the added cost, or if it is just a cool selling point for companies like Pagani to tout?

The basic concept for constructing composite materials is pretty straight forward.

A composite,, as in carbon fiver and the example you noted, is basically strands of a material that has great linear strength embedded in another material, like epoxy or resin, to keep the strands oriented in the desired direction.  Some mentioned fiberglass and that is decent example.

Here come the fun part.

We know the tensile strength, the maximum stress a material can withstand before failing, called the yield point, of the material we want to use.  Carbon fibers have strength along the fiber's length, very little in any other direction.

Now, we get out the slide rules (we used computers ) and figure out where the forces on a design part are, i.e., where are going to find push and pull, expand and contract and squeeze vectors.

Once we know that, we can orient the fibers in the direction where they can withstand the calculated stress.

We don't line them all up in the same direction, we want the part to be strong everywhere because the forces change when the part is doing its job, so some fibers are one way, some biased to that row, some perpendicular to other s row, etc, based on our calculated model of the part..

Embed it all in epoxy or similar materials to keep the fibers where we want them.

Test.

Try again.

Test.

Try again.

Repeat until success.

Now we have a lightweight, corrosion-resistant part that can resist the stress encountered during normal and excess operation within the limits of the machine.

I don't know what benefit the titanium strands offer, but one must very carefully consider using metals in composites.  Metals rust and can weaken under continued stress.  You break a wire coat hanger by repeatedly bending it at the same point: result:  heat and eventual failure  at that point.

Composites generally don't fail under continuous stress at the same point and they also do not expand and contract under temperature changes as much as a metal or minerals do.

However, as mentioned previously, when they do fail the composites tend to kersplode or shatter into tiny bits rather than bend or tear..

It is more complex that I have described, but them's the basics.

It's a fun science.

[Fog]

3 hours ago, M&P15T said:

I'm not really interested in debating this, because there isn't one. 

There is carbon fiber, and there is a whole lot of other composites, and you don't seem to understand that. Your example of SCUBA tanks is completely incorrect, as they use carbon fiber reinforced polymer, or CFRP. That is NOT the same thing as carbon fiber. 

Please, just drop this. 

The company literally says the hull was filament wound carbon fiber composite. The sub was a composite, built the same way as scuba tanks.

Wikipedia says it.

The university web page that started the project and built the prototypes says it.

Parts were also titanium.

You're right there is no debate about that. Look up it up.

 

 

 

[Walt Longmire]

At least they didn't suffer.

[Fog]

2 hours ago, Eric said:

On a tangent, a supercar maker who makes unusual, but very interesting cars is Pagani. The make the Huayra and some other models out of a composite called carbotanium. It is comprised of titanium wire that is plated with platinum, heated to like 500 degrees celsius, coated with a primer, then an adhesive and then coated with carbon. I am a little fuzzy on the whole process, but I assume this is done the the titanium wire first and then it is woven with carbon fiber into sheets. It is supposed to be light, strong as hell, with superior elasticity and heat resistance. It sounds really complicated to make and therefore very expensive. I wonder if it is truly a superior enough material to justify the added cost, or if it is just a cool selling point for companies like Pagani to tout?

 

Funny you mention the carbon fiber with titanium.

One of my most recent fishing poles is a composite of carbon fiber and some very exotic metals deposited onto the carbon fibers. Basically the metal is a carbon filled hollow tube.