Report about the failure of the OceanGate Titan published

[LTig]

The Canadian Transportation Safety Board published the report about the disaster of the OceanGate Titan submersible which imploded on June 18, 2023 in a depth of 3,346 metres, resulting in 5 fatalities. The report about the possible failure cause starts at page 104.

TL,DR: bad engineering practices and very bad risk management (careless rejection of warnings by experts in the field) are the likely causes. (EDIT: see page 120)

 

[Redacted]

Was it made by Topping or similar?

 

[LTig]

Proudly made in the US.

 

[Somafunk]

Was it made by Topping or similar?

All it needed was a Danny Ritchie upgrade kit

 

[Roland68]

The Canadian Transportation Safety Board published the report about the disaster of the OceanGate Titan submersible which imploded on June 18, 2023 in a depth of 3,346 metres, resulting in 5 fatalities. The report about the possible failure cause starts at page 104.

TL,DR: bad engineering practices and very bad risk management (careless rejection of warnings by experts in the field) are the likely causes. (EDIT: see page 120)

At this depth, the pressure is 335 bar.
If you look at videos on YouTube of pressure cookers exploding at 2.7 bar, you realize that this submersible had to withstand a force 124 times greater than that.

Normally, a submersible like this should be tested at double the pressure and for twice the maximum duration at depth.

I just read that the central pressure hull was made of wound carbon fiber. Unless they laminated it onto a sufficiently strong core tube made of aluminum alloy or titanium, that laminate had a very short lifespan. But any materials expert in the field should have known that.

 

[pablolie]

There was little need for an official report. People that worked for/with the egomaniac leader had warned the authorities repeatedly about the utterly unsafe and unprofessional practices. And speaking about gullible consumers, as we often do in ASR, this was at a grander scale.

 

[Somafunk]

I just read that the central pressure hull was made of wound carbon fiber. Unless they laminated it onto a sufficiently strong core tube made of aluminum alloy or titanium, that laminate had a very short lifespan. But any materials expert in the field should have known that.

That’s why every materials expert told him he was f**king crazy and refused to be involved

 

[LTig]

There was little need for an official report. People that worked for/with the egomaniac leader had warned the authorities repeatedly about the utterly unsafe and unprofessional practices. And speaking about gullible consumers, as we often do in ASR, this was at a grander scale.

It was necessary to find out what caused the implosion, as there were several possible suspects. The acrylic viewport was specified for a maximum depth of 650 m (!, see page 30) and was a highly likely suspect in my view. But it wasn't - it was blown out, not in.

 

[pablolie]

It was necessary to find out what caused the implosion, aas there were several possible suspects. The acrylic viewport was specified for a maximum depth of 650 m (!, see page 30) and was a highly likely suspect in my view. But it wasn't - it was blown out, not in.

What I read years ago was that there was material fatigue going on, and the owner ignored it based on the "it's worked before" premise, despite all his engineers crying out for caution. It's like trying to drive your car 150k miles without any maintenance as an Uber driver. There was no money for a new carbon sub. But there were rich customers, and with a few more he'd gotten the money to build a new one.

 

[Ricardus]

I was so stunned that it was an engineering failure! (sarcasm).

I knew that guy was a dangerous narcissist from that CBS (?) interview where he kept invoking Elon Musk and Steve Jobs. He wanted to be seen as a "rogue innovator" like those guys. His ego was DESPERATE for it. But do you think NASA is sending up any of their gear or living beings in Musk's rockets without proper testing and certification??

I'm not a a materials engineer, but I have a carbon fiber bike, and I know that carbon fiber works best under tension not compression. That is LITERALLY all you needed to know, NOT to make your hull out of carbon fiber.

Such pointless loss of life.

 

[JSmith]

carbon fiber works best under tension not compression

Hmm... compressive strength is still exceptional compared to aluminum or steel, provided the composite matrix is properly designed.


JSmith

 

[Owis]

Watch the documentary on Netflix

 

[Keith_W]

This reminds me of the famous argument by W. K. Clifford called "The Ethics of Belief", which is the strongest philosophical argument I have ever come across against all types of faith. In his essay, Clifford describes a wealthy ship owner who sold tickets for a trans-Atlantic crossing. He knew his ship was old, it was rickety, and it was in dire need of repairs. But he justified each trip by telling himself that the ship had survived many voyages before, and pushed his concerns aside. When the ship eventually "went down mid-ocean and told no tales", he quietly collected his insurance money.

Clifford said "verily, he was guilty of the deaths of those men", because "he had no right to believe on such evidence as was before him. He had acquired his belief not by honestly earning it through patient investigation, but by stifling his doubts". But what if the ship had safely arrived in New York? Does that alter his culpability? "Not one jot. He is equally guilty for believing something on insufficient evidence".

I read that essay in my early 20's and since then I have expunged every faith-based belief from my life. No religion, no ideology, and sometimes - if I suspect the science has been corrupted by ideology or politics, I question that science as well. There is no way I will climb aboard such any vessel that does not have rigorous government certification proving its safety. I have declined flights from friends who own airplanes. And there is no way you will catch me on a hot air balloon, let alone something like the Oceangate Titan or a Blue Origin Orbiter.

 

[Roland68]

Hmm... compressive strength is still exceptional compared to aluminum or steel, provided the composite matrix is properly designed.


JSmith

For one thing, such extreme pressure cycling (0 → 335 bar → 0) inevitably causes delamination at the weakest point—and such a weak point always exists—which then spreads during the next cycle of loading.
Added to this is the negative coefficient of thermal expansion of carbon fiber. At depth, the water temperature is around 0°C; this causes the carbon fibers to lengthen and thin, while the epoxy resin contracts. This, too, actively contributes to delamination.
Given these conditions, I find it remarkable that the accident did not occur until after 13 dives to that depth.

 

[kemmler3D]

any materials expert in the field should have known that.

They did, and the owner of the sub company firmly rejected all the good advice he got.

 

[Fledermaus]

For those new to this matter or interested in any way, this guy, who usually deals with plane crashes and air safety, made interesting videos (and even wrote a book) about this disastrous adventure - this is the 1st of 4 :

(Use auto translate if your French has got rusty )

 

[FrantzM]

Hi

The story of human advancement is one of taking risks , sometimes enormous. Oversized egos , unreasonable demands and expectations seem to be at the forefront of Human Advances..
Think about it for a second ( or several ) .. You have people that , this very minute, are eager, perhaps mentally , ready to go to Mars ... knowing very well what the challenges , no, the dangers are ... Heck ! we had a few people, now celebrated as heroes , that were willing to strap themselves to a bomb (which is what those rocket virtually are), to go to "space" ..

In this endeavor, the one we're discussing about, mistakes were made and some people paid with their lives, Im certain they knew the "ride" was extremely risky .. That didn't stop them , nor would that stop, other people in similar, perhaps riskier endeavors.

May those who lost their lives, RIP. May those who knowingly exposed them to grave danger pay the price.

...

Exploration (risk taking) shall continue ..


Peace and be safe you all

 

[Ruediger]

Some people can't work selfless / for a greater good even when granted or trusted with a task that is way larger and more important than some standard work. By granted I mean that this guy was allowed to do all this, no one stopped it, he grasped the opportunity and made it "his thing". It should spark responsibility in a person, but instead it sent an ego on a rollercoaster.

The world is lucky that it was no nuclear plant, giant hydro plant or commercial airline operated in such fashion.

(Followed the incident back then. What a display of massive personal shortcomings. Just sad.)

 

[Redacted]

What was the SINAD number for this machine?

 

[JSmith]

From page 109;

There were a few factors identified as contributing to the reduced compressive strength of
the cylinder, including the presence of severe ply waviness in localized regions of the
carbon fibre laminate, as well as visible porosity. It was also identified that some of the
processes used in the manufacturing of the cylinder may have allowed defects to be
introduced. For example, the process of vacuum bagging and curing the hull introduced the
potential for delamination and porosities. The process of grinding down the raised areas of
the cylinder to make them flush with the cylinder’s design curvature potentially introducing
defects on the surface of the cylinder, reducing the overall strength of the structure.

JSmith