Hacker News Reader

Comment by ommpto | Hacker News Reader

"Two months later, OceanGate faced similarly dire calls from more than three dozen people — industry leaders, deep-sea explorers and oceanographers — who warned in a letter to its chief executive, Stockton Rush, that the company’s “experimental” approach and its decision to forgo a traditional assessment could lead to potentially “catastrophic” problems with the Titanic mission."

https://www.nytimes.com/2023/06/20/us/oceangate-titanic-miss...

letter (pdf): https://int.nyt.com/data/documenttools/marine-technology-soc...

View on HN

I don't understand why they didn't just drop it to the bottom of the ocean without people hundred times to see if it still holds. Who experiments with a crew in the age of remote control sensors and computers?

I think they just didn't think there hull design would implode. In there minds the worst case is, they're stuck in deep ocean for a few hours until the backup dissolvable weights fall off and they pop back up to the surface (and then hopefully located).

From what I've read, in there minds there hull design was the best part of the sub. I inclined to believe he believed it, since the CEO frequently dove in it.

The hull was replaced because the previous one showed damage due to repeated stress cycling:

"This is shaping up as a rebuilding year for the nearly 11-year-old venture, based in Everett, Wash. The main task on the agenda is to build two new submersibles capable of diving as deep as 6,000 meters (3.7 miles), which is more than a mile deeper than the part of the North Atlantic ocean floor where the Titanic is resting.

OceanGate will take advantage of lessons learned during the construction of its carbon-hulled Titan submersible, which was originally built for Titanic journeys. Rush said tests that were conducted at the Deep Ocean Test Facility in Annapolis, Md., revealed that the Titan’s hull “showed signs of cyclic fatigue.” As a result, the hull’s depth rating was reduced to 3,000 meters.

“Not enough to get to the Titanic,” Rush said."

From:

https://www.geekwire.com/2020/oceangate-raises-18m-build-big...

From a link within that article:

> Because Titan was once known as Cyclops 2, the working titles for the new submersibles will be Cyclops 3 and 4.

So they lowered the depth rating of Titan back in 2020 .. but then continued to dive down to the Titanic with it?

With a new hull. But this was then also subjected to multiple dives but I'm not aware of any subsequent testing. Possibly if they had tested it defects would have shown up because that's pretty much the way this sort of structure responds to stress cycling. We'll never know unless a record of subsequent tests surfaces.

Isn't implosion like the one obvious danger of being deep underwater?

> I think they just didn't think there hull design would implode.

Even the diver that piloted it imagined at least one way how it could implode (window).

The carbon fiber hull has a limited cycle life. It's designed for a single-digits number of dives, and it becomes weaker on each cycle.

If it's a consumable, they should have tested at least one hull to destruction, just so they could be sure of it's failure modes.

Based on what I've seen, it doesn't sound like OceanGate had decided on a fixed number of dives. Instead they were planning to continually monitor it (x-ray scans after every dive and real-time acoustic monitoring during the dive) with the assumption that they would get some warning before it failed.

That makes sense, but to me that just means "keep dropping it until it implodes and then you can find out exactly how many dives it's good for". I still see absolutely no reason why humans should have been inside that thing. It's easy to criticize from an armchair, but goodness it just boggles my mind.

They did roughly that with the previous hull: it was used until it had to be derated. This accident was on the replacement hull which already had a few cycles on it... tested but supposedly not worn out.

Material science is hard, especially on a budget. This is definitely daredevil territory.

That puts a new spin on a “brittle unit test”

Testing is costly in terms of time and money, particularly with a submersible. It's one thing to test a piece of code, but testing a submersible under realistic conditions means basically arranging a full mission for every test run (which is hugely expensive, requiring a support ship, etc.). There's no such thing as perfect safety, which always has to be balanced with cost. I'm not saying Rush's approach was sound (he apparently eschewed more thorough testing) but testing that submersible a hundred times surely would have been cost-prohibitive.

Also the Titan did successfully complete ~20 deep dives from what I've read, so the design was apparently sufficient to stand up to the pressure more than once, meaning even a non-trivial testing program might not have detected the problem. Unfortunately the problem (as many have stated) seems to be in the choice of carbon fiber, which (particularly when taking into account the interfaces with other materials) will weaken over time even if the initial flaws are very small. All materials experience fatigue but the problem is much worse with carbon particularly under those kind of pressures.

I'm guessing they couldn't afford to without going bankrupt.

Then they couldn't afford it, period.

In the end all participants consented and were aware of the risks.

There's no absolutely safe way to dive that deep, just like there's no absolutely safe way to ascend K2. People still want to do it.

K2 is attempted by experts using their own gear under their own power. They know exactly what risks they are taking.

This submersible was basically a rollercoaster ride that wasn't up to spec. If a participant doesn't need to know or do anything on a trip, they are going for a ride not an adventure, and they aren't expected to be safety experts in the field.

Also one of the passengers was a teenager who was concerned about going, but went along to make his dad happy. Hardly a clear eyed risk taker who was fine with the risk.

1000% this. A previous participant Mike Reiss, former Simpsons producer, did a interview a few days ago where he all but compared himself to one of the astronauts on the Mercury missions. It was nearly borderline delusional.

He even said he was well aware of the risks involved and kissed his wife goodbye not knowing if he would see her again. Just because something is insanely dangerous doesn't make you an explorer, and you're not performing in any research capacity, you're a former writer for the Simpsons and this is TOURISM. Get some perspective.

> There's no absolutely safe way to dive that deep

That's true, but there are (substantially) safer ways. This design should have never been used for passengers.

I really draw the line there: innovators are free to do whatever the hell they want to do with their own lives and if a professional who really understand the risks decides that they want to take those risks they should be free to do so.

But to charge passengers for a ride requires a completely different attitude towards safety. No matter what you are going to write on your consent forms. Besides being unable to properly evaluate the risks inherent in your design they will be subject to all kinds of pressure to participate which will reduce their ability to properly assess the risks.

This is why we have different classes of aircraft, and why depending on your goals you will be assessed differently by the authorities if you intend to operate one for ferrying (paying) passengers.

> free to do whatever the hell they want to do with their own lives

Is that entirely true? In a scenario like this they're going to incur tremendous costs borne by others in search and recovery, and potentially put rescue personnel in harm's way. Modulo these things being used as useful exercise and training for the military.

That's true, but then we'd have to outlaw a whole bunch of other activities as well.

Besides the legal complications of being in a place that technically is outside of the legal boundaries of all countries, so who would enforce that?

> This design should have never been used for passengers.

That's cheap talk. As soon as there is some major accident, some people creep up to declare: it was obvious all along. Of course it wasn't quite obvious enough for them to actually make that declaration in advance.

Except for the experts Rush hired that did make that declaration well in advance.

That he fired.

Then sued.

This expert should get money after company dissolution as a compensation, IMHO.

> In the end all participants consented and were aware of the risks.

They consented, but were they aware of the actual risks? That seems unclear at best, given the active concealment of safety issues and the misleading marketing that has been cited in various reports.

> There’s no absolutely safe way to dive that deep

Nothing is absolutely safe, but deep submersion diving isn’t a new field, there are established safety standards and practices (including in the latter third-party audits to confirm compliance to the former) and OceanGate uniquely among operators of manned vehicles refused to conform to either (though it marketed its subs as exceeding the standards it decided not to be certified against). And its also unique in experiencing a manned disaster.

Now, we aren’t at the point where it can conclusively be shown that those two unique features are directly connected (and practical issues with investigating a disaster at this depth may not make that practical any time soon), but, its not unreasonable to suspect that they are.

> Now, we aren’t at the point where it can conclusively be shown that those two unique features are directly connected

I would take that bet.

> > Now, we aren’t at the point where it can conclusively be shown that those two unique features are directly connected

> I would take that bet.

And I would agree that that is where the smart money is, I’m just acknowledging that the actual specific cause of the disaster and any connection to specific cut safety corners remains unknown.

There are a lot of tell tales in how the debris field is structured.

The fact that the two end bells are separated from the central cylinder and that the cylinder itself can't be located pretty much singles out the carbon fiber structure. The company was aware of problems with previous iterations of the hull of Titan which may have been rebuilt at least once and possibly more than once (this is a bit unclear in what I've been able to dig up about it so far). If the window blew first I would expect things to look a bit different.

I wonder to what extent gross negligence trumps the language in the consent waiver.

> There's no absolutely safe way to dive that deep,

No, but using a vessel built the same way as the one James Cameron used would be safer (he did 33 dives).

This is how they test aircraft... It's very expensive and time consuming. Pilots, technicians, all staff, must be paid. You are subject to weather cancellations. It takes years. Like everyone has said, move fast and break things!

My thoughts exactly. How do pull a design out of your hat, against literally every expert's advice, and not test it a thousand times? It's insane.

`Over the years it has carried out more than 200 dives with its three submersible vessels in the Atlantic, Pacific and Gulf of Mexico.`

But not with the same hull. So that's a bit of a tricky statement.

https://www.geekwire.com/2020/oceangate-raises-18m-build-big...

They didn't change the name and technically the cylinder is just another part but it suggests that the same hull was used which isn't correct as far as I read it.

Right. Also, the difference in depths matter just as much as number of dives.

Reply on news.ycombinator.com