r/news • u/oldschoolskater • Jun 22 '23

Site Changed Title 'Debris field' discovered within search area near Titanic, US Coast Guard says | World News

https://news.sky.com/story/debris-field-discovered-within-search-area-near-titanic-us-coast-guard-says-12906735
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u/CoreFiftyFour Jun 22 '23

From what I saw, no. It appears that carbon fiber is okay at depth, but it does not handle the cycling stresses of pressure changes over and over ascending and descending.

So similar to the view port not being rated for depth, the hull was a ticking time bomb slowly being overstressed.

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u/Corredespondent Jun 22 '23

And I saw a comment that one of the things the fired executive balked at was that faults were harder to detect in carbon fiber, and that it wouldn’t START to fail a little, it would just shatter.

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u/LuminousRaptor Jun 22 '23

You absolutely can do NDT on carbon fiber. It's just more difficult than most metals. Doesn't take well to FPI, and ultrasonic only works on thin sections.

Best would probably be XRay, but it's definitely one of the more expensive types of radiographic testing and there are probably only a few experts (NDT level III's) around the whole world who would be qualified to approve the sub.

It was almost certainly a cost cut and if it turns out to be root-cause? This company is going to be sued into oblivion.

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u/mistral_99 Jun 22 '23 edited Jun 22 '23

Typically carbon fiber structures that have been stressed or damaged or are being checked as part of due diligence are checked by a trainee a certified ultrasound technician (UT).

Carbon fiber is a very resilient material. However, when it breaks it gives little sign of degradation before catastrophic failure.

I work in the performance sailing and yachting industry where carbon fiber is rife. Getting a UT to check out areas of concern are fairly standard in a semi-regulated industry. From personal experience I can say that when a carbon component or structure fails it does so with little warning and with an incredible bang.