Carbon Fiber Submarine Implosion: How Many Dives Can It Withstand?

I would like to see how a steel tube implodes.

Thank you! You did a wonderful job!

One of the problems with testing CF: You don't have one material to test.
It is a composite. You are testing the resin, the actual fiber, the fiber lay, and the layup of the material. (IMHO, especially after seeing one particular image of the CF tube after they layed it up showing obvious and multiple deformations of the surface indicating trapped bubbles, even if the design had been sufficient, the manufacturing method of the tube was flawed.)

Oceangate had some serious philosophical and cultural issues that lead to the tragedy. It is easy to focus on the materials, but the material/design/manufacturing choices are the SYMPTOMS of the problem, not the actual problem.

has anyone considered the different expansion and contraction of the odd material in the temperature ranges on the dive.?

To me the real amazement is how everyone says "obviously this couldn't work", but look at projects like "hyperloop" and think that would be possible. Vacuum and pressure are dangerous stuff.

Even on a small scale you showed that carbon is a bad idea in compression

This experiment was well done in every way, thank you for being so thorough. There is a possibility that the joint between the titanium and the carbon fibre was too rigid and slowly failed, allowing water to leak in on the air cavity. Instead of an epoxy only bond, perhaps using a silicon coating from a caulking compound on the outside, over the metal/CF joint would more closely represent seals in the structure. Applying it on the inside would more closely approximate the seals as well, but is very difficult to do on both ends. I think that may allow for more accurate pressure testing, and also reduce the chances of leakage.

And knowing is the other 50% of the conflict in question

Interesting that there are CF remnants on the end covers yet on the sub, there was nothing.

What if you put something inside the fiber tube like dead rat or raw chicken legs

Impressive work! Very insightful and professional 👏🏼👏🏼👏🏼 let’s hope those who are in the submarine business watch this vid and learn from it.

Can’t believe how fast the implosion is even when replayed at slow-mo!

That's pretty much how it happened, after a couple of dives, the wear and tear did them in. It was eerie to see both caps separate just as with the Titan.

You should have put a couple of figurines inside that tube and see what they look like after the implosion.

I wonder how close to your results the official investigation study will be - not only the values at pressure failure but also the destruction patterns of the carbon fiber

Very realistic 1/100th scale.

A guy with hair? And NO ACCENT?
WHAT IS THIS THE TWILIGHT ZONE?!?

Very informative content. Fantastic visuals. I feel like I'm watching a more scientific version of Mythbusters :) Thank you for this video. Also, I LOVE your Scandinavian accent.

You should have kept a small sausage inside the submarine.

The Titan design only had the fiber wrapped in one direction around the cylinder, back and forth from end to end as the cylinder spun. i believe your model also has fibers running longitudinally directly from end to end. So the model should be much stiffer and maybe less likely to suffer stress cracks from pressure cycling. I believe you would have to wrap your own tube replicating the wrap method used by OceanGate to really test the pressure cycling. And I agree a lot of model testing with an accurate scale model should have been done before full scale testing.

It's interesting to see the difference between the two implosions. In my opinion, albeit an amateur and inexperienced one, this video highlights the two greatest faults with this design; a carbon fiber body, and carbon fiber joined to titanium using adhesive to hold it together.

In the first implosion, the pressure is immediately increased to implosion depth. You can see the adhesive begin to fail just a moment before implosion, and you can see the implosion begin at that joint and propagate down the body of the carbon fiber tube.

In the second implosion, the chamber goes through several pressure cycles. It may not have been an exact 1:1 of the dives and pressure cycles which the real vessel experienced, but I believe it might've weakened the carbon fiber enough to cause the tube to fail before the adhesive on either of the ends. You can see in the second implosion how the tube failed in the center and propagated out to the ends.

I'm of the opinion is that a large part of the problem was that the carbon fiber was axially wound around the mandrill instead of bias wound. The use of the completely wrong material not withstanding

Water leak on submarine not ideal

finally a scientific real world test not like those computer generated made by children

Good job guys!!!

Make comparison to steel Vs cabon fiber..

Cool video if you could actually understand a word that guy says

Fascinating, so do you think the failure point was the carbon fiber itself or the adhesive? It didn't seem like they were very much carbon fiber left in the grooves that you cut for it.

Are the windows of the pressure vessel sapphire? Or what material?

Same as Ocean Gate, you guys also use zip ties to keep things in place. Keeping it real, literally.
I'm not trying to be a "funny" jerk. I was just shocked when I saw all those cheap zip ties on the Titan holding the wiring harnesses in place.

One thing I can’t wrap my head around is why didn’t they pressure test one to it’s breaking point before even going that deep? Or did they?

Finally someone test what is close to what happen to the titan. Excellent job.

You just did more testing than Oceangate did.

Hej Lauri. Jag tar det på svenska så kanske jag kan förklara det bättre. Jag hade velat att man testade men en cylinder som är en båge. Som en brovalv om du förstår vad jag menar. Gammeldags broar som typ bara var av sten o behövde egentligen ingen som fäste ihop stenarna. Om man skrivit ut en cylinder med välvda sidor istället då kan den klara mer tryck. Gamla handgrävda brunnar med tegelstenar på vägarna var alltid välvda så att hålet var kanske 1meter uppe o längst nere men mycket mer på mitten. Jag hoppas jag förklarade det bra. O att översättningen blir bra till andra språk. Mvh Mattias från Sverige.

Consider also the environment with carbon fiber being glued to metal. The different properties of the carbon fiber versus the metal and the glue adhesive I believe would lead to weakning and delamination of the carbon over so many changes in temperature and environment. With or without pressure involved

You sound Finnish, oot sä suomalainen?

Amazing video.
We've likely all seen the train tank imploding video where air is removed, we've all seen cans being heated then put in cold water, but I've yet to see just a mere demonstration of carbon fibre being loaded like this.
Just goes to show really.

It's good to see Anni this time.. She is comfortable appearing as natural human being without the the tight-pants, rainbow-coloured hair and excessive enthusiasm.

SCBA tanks are pressurize and depressurize over and over. They don't explode?

Carbon fiber is a poor choice for submarines, all military submarines are made from strengthened steel ,not Carbon fiber

Strawberries, nah ,want to see it fail with meat with bone inside during failure

Imho, you should test it 40 times at 70Bars, not at 40Bars, and made that cycles in more slow pace, lets say 15 minutes per "dive". Just because it will produce cyclic stress exposure damage much more likely. Of course, it will take much more time and effort, but result will be more scientifical, I guess...

Unfortunate on the second CF tube but no test is a bad test. You always learn something.

It is interesting that both had the same implosion pressure even after many cycles for the second tube. It might be worthwhile to make 3-5 tubes and test them all straight to the implosion depth, so get a good average and see if the first tube was maybe weak due to an unseen imperfection, while yourvsecond tube was stronger and just by coincidence showed the same implosion depth due to the previous cycling.

So, this wpuld be like building a submersible out of tupperware, with two titanium rings?
Rush's design teminds me of a big propane tank that sits in a backyatd

Thx you for this video

More interesting seeing a water chamber doing that then an hydraulic press (Kind of unfair testing i think since a press is a solid and water ain't really a solid)

Nowadays it's so funny how people are busy crashing and talking about crashing various carbon cylinders as if it's something utmost important thing in the world)))
It's ok with this channel because they need to do something with the hydro press.

Very good, helps explain why they recovered the end rings complete minus any trace of cf still attached.