Sub implosion: safety issues raised in 2018, whistleblower subsequently FIRED

[Ace-Garageguy]

EDIT: For those not following the news, debris from the instantaneous catastrophic failure last Sunday of a small submarine taking sightseers 13,000 feet under the ocean surface to visit the remains of Titanic was located on Thursday, all occupants presumed lost

QUOTING FROM   https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired/

"The director of marine operations at OceanGate, the company whose submersible went missing Sunday on an expedition to the Titanic in the North Atlantic, was fired after raising concerns about its first-of-a-kind carbon fiber hull and other systems before its maiden voyage, according to a filing in a 2018 lawsuit first reported by Insider and New Republic.

David Lochridge was terminated in January 2018 after presenting a scathing quality control report on the vessel to OceanGate’s senior management, including founder and CEO Stockton Rush, who is on board the missing vessel.

According to a court filing by Lochridge, the preamble to his report read: “Now is the time to properly address items that may pose a safety risk to personnel. Verbal communication of the key items I have addressed in my attached document have been dismissed on several occasions, so I feel now I must make this report so there is an official record in place.”

The report detailed “numerous issues that posed serious safety concerns,” according to the filing. These included Lochridge’s worry that “visible flaws” in the carbon fiber supplied to OceanGate raised the risk of small flaws expanding into larger tears during “pressure cycling.” These are the huge pressure changes that the submersible would experience as it made its way and from the deep ocean floor. He noted that a previously tested scale model of the hull had “prevalent flaws.”

Carbon fiber composites can be stronger and lighter than steel, making a submersible naturally buoyant. But they can also be prone to sudden failure under stress. The hull that Lochridge was writing about was made by Spencer Composites, the only company to have previously made a carbon fiber hull for a manned submersible. (That submersible was commissioned by explorer Steve Fossett for a record-breaking dive, but he died in a light aircraft crash before it could be used.)

Lochridge’s recommendation was that non-destructive testing of the Titan’s hull was necessary to ensure a “solid and safe product.” The filing states that Lochridge was told that such testing was impossible, and that OceanGate would instead rely on its much touted acoustic monitoring system.

The company claims this technology, developed in-house, uses acoustic sensors to listen for the tell-tale sounds of carbon fibers in the hull deteriorating to provide “early warning detection for the pilot with enough time to arrest the descent and safely return to surface.”

Lochridge, however, worried in the lawsuit that the system would not reveal flaws until the vessel was descending, and then might only provide “milliseconds” of warning before a catastrophic implosion."

END QUOTE   (read the rest of the article at the link provided above)

I've worked with composite materials in engineering and fabrication capacities for decades on and off. Anyone familiar with carbon fiber knows 2 things: 1) though it's very good in tension (where the pressure would be coming from INSIDE a pressure vessel, like compressed gas tanks), it's not so hot in compression (where the pressure would be coming from OUTSIDE a pressure vessel, like a submarine hull), and 2) although very strong up to their design limits, carbon structures are inherently brittle, and when they fail, they do so instantly, literally shattering, with almost no yield or deformation prior to catastrophic failure, unlike the behavior exhibited by most metals.

Anyone familiar with composite structures is also aware that small defects in a composite laminate can propagate within the structure over repeated cycling, leading to eventual catastrophic failure at well below the design loading.

Quoting another source, an engineer for a company that's designed and built numerous submersibles using carbon:          https://www.designnews.com/industry/carbon-fiber-safe-submersibles-when-properly-applied

"The key is diligence in designing and testing the composite structures, Hogoboom explained. “We have a very high confidence in the strength of what’s been built,” he said. “We use engineering models, but we test to failure to validate what’s been modeled. That’s a crucial step that OceanGate has skipped," according to Hogoboom. “They never brought an exact clone to failure.”"       END QUOTE

Looks like the OceanGate company head, quoted as saying he didn't want experienced "50 year old white guys" on staff because they're not "inspirational" might have been mistaken about that.

https://www.breitbart.com/tech/2023/06/21/oceangate-ceo-didnt-hire-50-year-old-white-guys-for-titanic-sub-because-theyre-not-inspirational/

Yup, I'm pretty inspired.

 

Edited June 25, 2023 by Ace-Garageguy
TYPO

[BlackSheep214]

IBTL.....

[Ace-Garageguy]

18 minutes ago, BlackSheep214 said:

IBTL.....

Nothing in the least controversial to ignite a firestorm here.

Just stating facts.

[Classicgas]

Reminds me of the warnings given to NASA about the solid rocket booster seals potentially failing in freezing temps. It's all pretty darn sad.

[NOBLNG]

Tragic? The only one I feel sorry for is the 19yo son who didn’t want to disappoint his father. They were all wealthy enough and intelligent enough that a little bit of research would have turned up apparently credible warnings about the safety of the vessel and the cavalier attitude of the operator. 😕

[bobthehobbyguy]

Definitely tragic. Usually when somebody(in this case the CEO) who makes the poor decisions seldom pay the ultimate price for it. When you are going to operate in such a harsh environment you simply cannot take shortcuts. Those shortcuts will eventually catch up with you. And being wrong just once in this case is a fatal error. Doing all the due diligence and doing the proper testing will help but there is always the potential for a failure in such an unforgiving environment.  Proper testing always important.

[Mark]

The one thing you can say about that guy, was that he put his money where his mouth was, and wasn't content to just let others test the thing out by themselves.

The other thing is, it's about time that site was left alone.  It's a gravesite, not a theme park.

[1972coronet]

"Stepping-over dollars to pick-up dimes.", or some such. Typical U.S. business practise (exponentially worsening since the 1980s). 

[Raoul Ross]

moar

https://www.theregister.com/2023/06/22/oceangate_titanic_titan_sub_implosion/

 

[KMcc]

Unfortunately, seems like they tested it to failure without realizing it. Sad...

[Ace-Garageguy]

This unfortunate occurrence also brings into focus a disturbing push by the new-mo-better-don't-need-no-fogeys-tellin'-us-nothin engineering community to do away entirely with physical prototypes, and rely solely on computer modeling for testing...going straight from CAD/CAE to production.

Can you say "stupid", boys and girls?

EDIT: And now I see the internet is awash in "experts" condemning carbon fiber out of hand as being unsuitable for submersibles...the typical talking-out-their-backsides-rebleaters with probably no more real-world experience with the stuff than putting a poorly-made carbon hood on their fartcan-equipped clapped out Civic, and seeing it shatter when they drove into somebody while texting.

 

Edited June 25, 2023 by Ace-Garageguy
ADDITIONAL INFORMATION

[OldTrucker]

2 hours ago, KMcc said:

Unfortunately, seems like they tested it to failure without realizing it. Sad...

Over 50 test dives and three to the Titanic of I read reports correctly.

That is a lot of stress it was subjected to without any proper inspection for stress if it was even possible to find.

[89AKurt]

I'll avoid posting morbid humor memes.  This sure looks like the problem.

[PowerPlant]

The bicycle helmet alone should have been a red flag to anyone with half a wit, let alone the talk about plexiglass being great, because it first “crackles” as a “huge warning that it’s about to fail”. At a depth of 3800 meters? This incident definitely proves that some people have entirely too much money and nowhere near enough grey matter. 

[Dave Ambrose]

4 hours ago, OldTrucker said:

Over 50 test dives and three to the Titanic of I read reports correctly.

That is a lot of stress it was subjected to without any proper inspection for stress if it was even possible to find.

You could probably submerge the section in water and check it ultrasonically. Back in the '70s we built a machine that did that for tires. The return wave will be different in the presence of one or more delaminations. That said, I'm going to speculate that the cause will ultimately be due to the carbon fibers breaking rather than delamination. 

[slusher]

17 hours ago, Mark said:

The other thing is, it's about time that site was left alone.  It's a gravesite, not a theme park.

So true, told my wife something similar!

Edited June 26, 2023 by slusher
Typo

[Mike C]

6 hours ago, 89AKurt said:

I'll avoid posting morbid humor memes.  This sure looks like the problem.

It should have had a mounting plate bonded to the CF and then screwed to the mounting plate.

[Ace-Garageguy]

Ignorance, meet hubris. Y'all have a lot in common, so let's see what you can come up with together.

Oops, sorry. It's pretty obvious you guys have been working together hand-in-hand since the dawn of Man.

Edited June 26, 2023 by Ace-Garageguy
TYPO

[Ace-Garageguy]

8 hours ago, Dave Ambrose said:

You could probably submerge the section in water and check it ultrasonically. Back in the '70s we built a machine that did that for tires. The return wave will be different in the presence of one or more delaminations. That said, I'm going to speculate that the cause will ultimately be due to the carbon fibers breaking rather than delamination. 

Ultrasonic testing is SOP in the aerospace and other industries that depend on high-performance composite structures.

It's well known technology, and continues to evolve rapidly due to the proliferation of composite applications.

A brief overview, with some of the issues and limitations explained.

https://www.sciencedirect.com/science/article/pii/S2588840420300342

https://www.compositesworld.com/articles/how-ultrasonic-testing-can-find-flaws-in-composite-materials

NDT (non-destructive testing) methods for composite materials

https://www.sciencedirect.com/science/article/pii/S2452321616000093

Ultrasonic NDT of composite materials, an overview

https://www.sciencedirect.com/science/article/abs/pii/S2214785322074296

Edited June 26, 2023 by Ace-Garageguy

[slusher]

I wonder if they will bring as much of the sub wreckage as they can for testing?

[iamsuperdan]

What's a shark's favourite fast food?

Five Guys.

 

 

 

Anyway, I think the amount of attention given to this story for exceeds the amount of attention it deserves.

Tragic for sure, but I think the hundreds that died on the migrant ship last week is a more important story. But I guess they're not wealthy, so obviously not worth the attention.

 

 

 

[Ace-Garageguy]

7 minutes ago, iamsuperdan said:

Anyway, I think the amount of attention given to this story for exceeds the amount of attention it deserves.

Tragic for sure, but I think the hundreds that died on the migrant ship last week is a more important story. But I guess they're not wealthy, so obviously not worth the attention.

You're missing the point entirely. I stated it above.

16 hours ago, Ace-Garageguy said:

This unfortunate occurrence...brings into focus a disturbing push by the new-mo-better-don't-need-no-fogeys-tellin'-us-nothin engineering community to do away entirely with physical prototypes, and rely solely on computer modeling for testing...going straight from CAD/CAE to production.

This kind of stupidity has the potential to affect everyone who relies on anything made by somebody else.

[bobthehobbyguy]

10 hours ago, 89AKurt said:

I'll avoid posting morbid humor memes.  This sure looks like the problem.

This picture is mind boggling. I simply can't believe that anyone could think that was a proper way of doing that. Complete idiocy. Wonder what other things were done like this.

[Ace-Garageguy]

1 hour ago, bobthehobbyguy said:

This picture is mind boggling. I simply can't believe that anyone could think that was a proper way of doing that. Complete idiocy. Wonder what other things were done like this.

Well see, if you have rainbow-dyed hair, know nothing about real-world materials or fasteners or much of anything that you can't do with your phone, and come from a "diverse" background, you don't have to think about stuff like driving screws into a pressure hull that has to withstand roughly 6000 pounds per square inch. That's for old fogeys.

Edited June 26, 2023 by Ace-Garageguy

[Mike C]