Posted on 07/05/2023 3:38:26 AM PDT by spirited irish
David Lochridge, a submersible pilot and engineer who had served in Great Britain’s Royal Navy and worked all over the world, had expressed reservations about the design and build of OceanGate’s submersible, but his concerns were reportedly dismissed. He found numerous problems with the vessel, including the carbon-fiber hull having “very visible signs of delamination and porosity,” the glue for ballast bags coming off, sealing faces with errant plunge holes, and O-ring grooves whose design was not standard, among many others, The New Yorker reported. When Lochridge brought up his concerns at a company meeting, he was fired.
(Excerpt) Read more at dailywire.com ...
ping to article of interest
Everything I have read and heard makes me agree with the idea that the (former) OceanGate CEO was a dangerous and narcissistic nutjob.
Independent of whether carbon fibre was the best choice of materials for this application, and whether layup of layers is the best construction method for this, evidence of delamination demonstrates after only a few cycles suggests poor cleanliness and quality control during layup.
Yes, everything about the slapdash design, incorrect material selection, sloppy construction, lack of adequate testing, and refusal to obtain certification screams unsafe and dangerous. People in the know rejected the entire mess. The CEO had to convince gullible, wealthy individuals to fork over US$250K for a session of undersea Russian roulette.
Carbon fiber is extremely strong in tension. In compression it sucks. There was about 6000 psi of compression on that hull.
OceanGate was coined The Macgyver submersible afterthefact by engineers who really only gave it a quick glance. More to follow I reckon.
Delamination at depth or at speed (Aloha Flight 243) can have disastrous outcomes.
Yeh tht's it...just like the astronauts that got blown up...they wanted to be really, really famous. s/
If the dead CEO inherited family wealth, maybe a wrongful death lawsuit could tap into the CEO's estate.
It was merciful that the implosion occurred in one thousandth of one second. The occupants of the death trap were killed instantly and did not know what happened. Stay tuned for huge lawsuits; the lawyers will find the deep pockets.
My guess is the lawyers will go after the carbon fiber material supplier, the hull construction company, or others involved who may have deep pockets, including liability insurance. Do not know if OceanGate has/had insurance coverage.
The structural problem is knowing how it failed. The reason a compressed vessel normally fails is actually buckling - a sphere or hoop deforms out of round, and at a certain stress this becomes untable and the sphere collabses into two "flat" plates. That is why in a normal submarine hull you have large I-beam hoops - to keep the hull round so that strength is controlled by compressive hoop stresses and not buckling.
Expert “white” pilot...
Miss the actual point much?
The guy willingly risked his life - along with others - as he pooh-poohed safety measures...and refused to concede he was doing anything wrong.
Excellent explanation, thx.
With a magazine fed handgun.
However, if the plaintiffs can prove criminal negligence, and the CEO's estate has money worth chasing, they will chase it.
As to suppliers, no manufacturer would offer any warranty, or do business with the CEO without a blanket release.
Is Lockridge white, and 50-something? Obviously, he wasn’t qualified to be working for OceanGate. I mean, c’mon man!
I watched them attaching the ends to the carbon tube. It looked like they thew a painting party to help spread the adhesive. Nothing that I saw showed concern about quality control. Looked like 5 people without experience spreading bondo.
And the compressive strength of expoxy can be as high as 25 kpsi. It's a good engineering problem. Submarine hull steels used to be about 80kpsi and are more recently 120kspi or more. But harder steels are not necessarily tougher steels. It is a tradeoff between strength and toughness and in a military vessel you want a tough steel to withstand explosive devices or impacts with seamounts in addition to overall hull strenght.
So the problem with carbon fibre epoxy hulls is that the vessel becomes quite thick in comparison with the volume. Normal submarine hulls using high strength steels or titanium [if you can afford it - and the Russians could and the US couldn't] are pretty thin by comparison.
It was perhaps a flawed choice but it requires a detailed analysis to understand exactly how bad it was and not just a oh, carbon fibre is weak under compression [weaker is not weak] and so it is not an actual analysis. Now, as in all engineering practice, the burden of proof is on the designer and not the detractor and the designer clearly failed in the burden of proof.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.