Titan/Titanic tragedy

James Cameron, who has also become an expert on deep sea craft, commented that carbon fiber is great in tension but poor in compression. Hence he concluded that it was the wrong choice of material from the start.
 
I watched the piece with Cameron and Ballard. Wish it was longer to get an even better prospective on the event.
 
My dad is the guy who suggested cutting a hole in the side of the ship to launch subs from (and was shown doing the job) in Aliens of the Deep. They had a backup set up to launch in rough seas, but it didn't work out smoothly. Cameron was fuming and said to toss everything overboard and start with a new plan. He was serious about that, my dad hid the winches and hardware in his quarters for the rest of the filming. Now I can actually say that James Cameron bought me the 20k Grainger winch that I've got mounted to my frame-stretched Samurai.
 
rwm said:
James Cameron, who has also become an expert on deep sea craft, commented that carbon fiber is great in tension but poor in compression. Hence he concluded that it was the wrong choice of material from the start.
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The problem with cf composite isn’t actually the carbon filament, its the epoxy matrix that it sits in.

The epoxy is so rigid, it doesn’t deflect under pressure, it cracks/crazes. Very often, that cracking/crazing happens deep in the structure between the layers, which is called delamination. When a composite structure delaminates, it might as well be made of wet cardboard….

Each successive pressure/release cycle causes the crazing to progress. The problem is its an insidious failure. Meaning: you can’t see it until it fails. There are some NDT techniques that may so it up, but I don’t get the feeling the “maverick” CEO/pilot was in to doing a lot of maintenance or inspection.

My last Helo was a high percentage of CF, kevlar, etc. It took a lot of very specific maintenace and inspection to keep it on the line. Was wondrous stuff, but you have to use it EXACTLY in the application it was designed for and it was silly delicate in any manner it was not designed to be loaded.

We actually had a problem with the tail rotor half plates because they used CF in a way that it wasn’t really designed for. Basically, they loaded it in a direction it shouldn’t have been.

I landed once and went up the ladder to inspect the tail rotor (called an A check) and we were about 30 mins or so away from a total failure. It was cracked and split so badly I coukd barely make it back down the ladder and had to lie in the infeild grass for about 20 minutes before I was able to stand again.

My aircraft commander came back to see why I was laying in the grass, all I could do was point up the ladder at the tail rotor. He climbed up, took a look and a few seconds later he was lying in the grass beside me….shaking almost uncontrollably.

We used to call loss of tail rotor “smoke meat 2” because loose the tail rotor and its all over…you were basically “smoked meat”, hence the name.

We didn’t move it an inch that day, got a hotel and went out to the bar and drank heavily that night…
 
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My gut instinct tells me the owner of the company didn't fully appreciate just how much pressure they were dealing with. Numbers are one thing but understanding those numbers without a visual demonstration (they have one now) is something else.
 
I think you can look for cracks inside CF - my brother told me about a CF bike seat post he bought and he got it scanned (ultrasound? X-ray?) at his job. They found a compression crack where the seat clamp had been tightened so he threw it out. One reason (in addition to cost) that I've never bought into CF bike handlebars.

Don't know how any of that would apply to a 5" thick piece backed by steel or titanium though.

Spooky how another father and son pair turned down seats on that ride after the son said it scared the crap out of him. I bet the mum of that boy that died wished they'd listened a bit harder to his fears.
 
rwm said:
James Cameron, who has also become an expert on deep sea craft, commented that carbon fiber is great in tension but poor in compression. Hence he concluded that it was the wrong choice of material from the start.
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Very true. I flew model gliders competitively, and a winch launch is extremely hard on the planes, especially F3B winches with mono (which builds up more tension). Under compression the top of the spar would fold, or blow off the layups if you exceeded the parameters. Carbon is great though, it creates a super light weight composite, and if you do the layups right is strong as anything.. but less so in compression.

There are all different epoxies. Some are super hard to get hold of, and are only available in 55 gallon drums.. Some are made for heat, some are made for elasticity, so you really need to read the specs, and the proper use. Some require post heat treatment to fully cure/harden.

The drawback to Carbon fiber is when it goes, it's not gradual.. It's all at once. I have lost a few planes back in the day due to catastrophic failures.
 
pontiac428 said:
This is exactly what set the tone for me as I watched the s**tshow unfold. Privilege has it's privileges.

I'm not sure how paid tourism came up when this was supposed to be an experimental thing for exploration... I'm just glad the owner/operator/proponent was on board, and no kittens were hurt.

I got ten submarines I can see from my office window, so you bet this was the hot topic of conversation this week.
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Which 10 submarines can you see from your window? I was on a submarine tender back in the day servicing IC gear on Squadron 6 boats.
 
It's sort of ironic.
Part of the reason the Titanic sank was because it was a single hull design.
Then the Titan goes down there with a single hull design.
It should have had a double hull with the inner one being far more stable than the outer one.
And they should have had a test device.
I don't know that it's possible but before every dive the craft should have been pressurized to 3X max pressure at depth.
 
mattthemuppet2 said:
I think you can look for cracks inside CF - my brother told me about a CF bike seat post he bought and he got it scanned (ultrasound? X-ray?) at his job. They found a compression crack where the seat clamp had been tightened so he threw it out. One reason (in addition to cost) that I've never bought into CF bike handlebars.

Don't know how any of that would apply to a 5" thick piece backed by steel or titanium though.

Spooky how another father and son pair turned down seats on that ride after the son said it scared the crap out of him. I bet the mum of that boy that died wished they'd listened a bit harder to his fears.
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Actually, they just had the mother on the news.

She was supposed to do the dive with the father. The son really wanted to go so she gave up her place to the son.

Poor woman is going to be in multiple years of therapy….
 
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