[rob74]

The use of the controller is symptomatic of their attitude, but I agree that it's probably not as relevant as, say, using an untested (and apparently untestable) carbon fiber hull:

> Lochridge’s concerns mainly focused on the company’s decision to rely on sensitive acoustic monitoring – cracking or popping sounds made by the hull under pressure – to detect flaws, rather than a scan of the hull.

Lochridge said the company told him no equipment existed that could perform such a test on the 5in-thick (12.7cm-thick) carbon-fiber hull.

“This was problematic because this type of acoustic analysis would only show when a component is about to fail – often milliseconds before an implosion – and would not detect any existing flaws prior to putting pressure on to the hull,” Lochridge’s counterclaim said.

Source: https://www.theguardian.com/world/live/2023/jun/21/titanic-s...

[sn41]

Interesting... This is similar to the concerns that Vince Weldon, the Boeing engineer had over the 787 Dreamliner hull made of composites: that flaws could not be found by a visual scan.

https://en.wikipedia.org/wiki/Vince_Weldon

[twic]

I have a carbon fibre fork on my bike. I had a low-speed accident a few years ago, and took the bike to a mechanic to get it checked out afterwards. He said he'd checked everything, and it was fine - except the fork, which he had no way of telling if was undamaged or about to fail. I think i'll get steel next time.

[hasmolo]

this isn't true anymore. you can get carbon bikes scanned after and accident to find any internal damage. Ruckus in Portland, OR is where i've shipped to before with luck, but there's a lot more local options now depending on the scene

[twic]

TIL! Apparently they do it with an ultrasound instrument:

https://www.olympus-ims.com/en/insight/ruckus-composites-ins...

[mrweasel]

Out of curiosity, does that actually work out financially, or is it really cheap or are carbon forks really expensive?

[benglish11]

You probably wouldn’t do this for a fork. You’d just replace it. The carbon frame though can be expensive

[HankB99]

Ouch! Folks across the street own a bike shop and sponsor an annual criteruim. Last year there was a crash right in front of our house - touch of wheels I suppose. There's a slight hill at the end of the street and I guess the riders could have been going in excess of 30 mph or more. No one badly hurt AFAIK but one bike had a broken frame. In this case no fancy equipment was required to detect the flaw. :-/

[major4x]

You may be interested in having a look at this relevant and interesting article "Nanoscopic origin of cracks in carbon fibre-reinforced plastic composites":

https://www.nature.com/articles/s41598-019-55904-2

[MuffinFlavored]

> The use of the controller is symptomatic of their attitude

https://www.theverge.com/2017/9/19/16333376/us-navy-military...

https://taskandpurpose.com/tech-tactics/us-military-video-ga...

https://www.pyrosoft.co.uk/blog/2007/11/04/army-fly-uav-spy-...

[AntonyGarand]

Xbox controllers are way ahead of low-end logitech controllers though, so the point stands: If you want to control the device using a controller, might as well pick a good reliable one instead of the cheapest option available.

[relbeek2]

I worked for a defense contractor, and we had initial plans for a contractor to build us a wireless controller. Their controller was an ugly box-shaped controller that they wanted to charge us 200k. I redesigned the architecture of our system so that we could use an Xbox controller instead.

There is no reason why these controllers can't be used over some other "industrial" controller, as long as you design the system appropriately to account for failures, which you should be doing regardless of what controller you select.

[distortionfield]

I’ve always hated this aspect of journalism- news stories latching on to an innocuous detail and then playing it up to make the whole operation seem like a circus. It plays to the Dunning-Krueger effect so hard.

[adql]

Or shove like 3 spares into a box somewhere on the vessel. $30 is not some bottom end falls-apart-if-you-look-at-it-wrong quality either

What's more perplexing is using a wireless one

[gukov]

Perhaps their decision was dictated by how easy it was to integrate with one vs the other (drivers, etc).

[omniglottal]

Nothing is untestable. If validation results in destruction, then destructive testing is how this is done.

Failing to test is a choice, similar to the choice made by a software engineer who determines, without testing, that their production service has no bugs.

If a component's flaw can only be detected right before a failure, we need statistical analysis of multiple such failures being intentionally induced to estimate the component's limits.

Not finding or knowing about existing limits or flaws is the direct result of not looking for them.

[salawat]

THIS.

As a Quality Assurance person, this is what drives me up the wall, across the ceiling, and down the other wall.

You can always do a test run. Not doing that test run is essentially saying every person you subject to that system is not worth the trouble of doing the test.

[berniedurfee]

FOMO is a helluva drug.

[jjk166]

No one was claiming that it was untestable, the company did decide to go with an acoustic monitoring, which is a destructive test, instead of a scan, which is a nondestructive test. The company claimed there was no non-destructive test that could be done. The issue is that when you're dealing with short run custom components, like the hull of a submarine, just because one passes a destructive test doesn't mean the others are free of manufacturing defects. You can't do useful statistical analysis when your sample size is small.

[Hamuko]

The details about the single window on the craft is also pretty damning:

>Further, the craft was designed to reach depths of 4,000 meters (13,123ft), where the Titanic rested. But, according to Lochridge, the passenger viewport was only certified for depths of up to 1,300 metres (4,265ft), and OceanGate would not pay for the manufacturer to build a viewport certified for 4,000 metres.

[N19PEDL2]

I read about the huge lack of safety measures on the submarine, and now this. I am beginning to think that perhaps the CEO of the company has voluntarily decided to die with his unfortunate fellow passengers. I know mine is big speculation, but taking the glass viewport to 300% of its certified maximum strength in an environment where the slightest setback can be fatal can no longer even be considered as "taking risks."

[nly]

Depends what certification entails. The company that certifies the ports might only have a sub that can go to 1300meters

Doesn't mean that the design isn't mathematically sound to far deeper.

[me_me_me]

there was a guy in other post on this story.

He says that testing of the composite materials is really difficult in comparison with metal. As they fail catastrophically without material stress.

Quotes like: "Lochridge’s concerns mainly focused on the company’s decision to rely on sensitive acoustic monitoring – cracking or popping sounds made by the hull under pressure – to detect flaws, rather than a scan of the hull."

are quite chilling in hindsight

[jimnotgym]

If the news report is true, some sonar bouy heard a knocking sound.

If they were knocking on the hull, at least we can be fairly certain that the hull did not implode.

[adventured]

We can't be fairly certain of anything regarding that knocking sound. They have no idea what it was and were not certain that it came from the sub.

[mechhacker]

Could mean a lot of things

Could be a pop of the hull that then flooded the inside almost immediately. Would like to see failure tests of how these kinds of hulls fail.

Other subs that failed with other hull designs were pretty gruesome, like Scorpion