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Titanic tourist submersible goes missing with search under way

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581–590 of 649 posts

Re: Titanic tourist submersible goes missing with search under way

#581

Earlier quoted context omitted.

Its a slur for prostitutes in German ;-)

And with that in mind, you may want to re-read the post you replied to. (That's about as close to explaining the joke as I'm willing to go.)

Haha gotcha, but Huren also means renting in Dutch (with no other connotation AFAIK)

Re: Titanic tourist submersible goes missing with search under way

#582

Earlier quoted context omitted.

And literally steered with a cheap game controller. There's a YouTube video from CBS of their reporter taking a trip on this thing. It's almost comical how cheap it seems.

What’s wrong with game controllers? They are built to be ergonomic and in use for extended periods of time. Also a lot of people are already familiar with how to use them. Not saying we should replace every bespoke interface with a game controller, but using a game controller isn’t necessarily bad either.

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Re: Titanic tourist submersible goes missing with search under way

#583

Earlier quoted context omitted.

If your design breaks at less than the target then you really have to question the logic of continuing with that design. Making it slightly bigger won't fix the inherent issue with the materials. They're potentially opening themselves up to charges for killing these people. They knowingly or recklessly put them on a boat when it isn't capable of reaching the depth safely and now they are dead.

The fact they took it to some testing facility to test for cyclic fatigue shows that they understood that it was an unknown in the design, decided to test it at a facility designed for exactly that, it failed so they redesigned presumably with a design to mitigate the failures of design one. They probably took design two through the same testing process, and presumably it passed or they wouldn't have paying guests in…

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Re: Titanic tourist submersible goes missing with search under way

#585

Earlier quoted context omitted.

And literally steered with a cheap game controller. There's a YouTube video from CBS of their reporter taking a trip on this thing. It's almost comical how cheap it seems.

What’s wrong with game controllers? They are built to be ergonomic and in use for extended periods of time. Also a lot of people are already familiar with how to use them. Not saying we should replace every bespoke interface with a game controller, but using a game controller isn’t necessarily bad either.

Good point. Might be nice to have some redundancy if a game controller is used for a mission critical component, but apparently, the US military approves.

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

Re: Titanic tourist submersible goes missing with search under way

#586

Earlier quoted context omitted.

>Metals are uniform and broadly predictable. That's not true at all: metals have a grain structure, and how those grains are oriented can change the metal's properties in different directions. >Composites vary cure to cure. Metal castings can vary from cast to cast.

Forging and heat treatment are processes to introduce uniformity of metallic grain structures. These have been perfected over hundreds of years. I challenge you to find a single structural component in a safety-critical context which is made of cast metal.

https://www.investacast.com/industries/safety-critical/

These folks, among others, make a lot of them. You are also incorrect about forging being used to introduce uniformity into the grain, it is typically (though not always, as some forging operations may just be for establishing shape) to stretch the grains such that they are oriented along the load path, resulting in higher allowable stresses. Look up highly loaded aircraft parts like landing gear, they are typically forged to establish the grain direction and then machined to final dimension. Nothing stops you from heat treating metal after it has been cast, either. Some heat treatments are also expressly to produce nonuniform conditions in the metal, case hardening for example.

Re: Titanic tourist submersible goes missing with search under way

#587

Earlier quoted context omitted.

And literally steered with a cheap game controller. There's a YouTube video from CBS of their reporter taking a trip on this thing. It's almost comical how cheap it seems.

What’s wrong with game controllers? They are built to be ergonomic and in use for extended periods of time. Also a lot of people are already familiar with how to use them. Not saying we should replace every bespoke interface with a game controller, but using a game controller isn’t necessarily bad either.

> What’s wrong with game controllers?

They are made for living rooms and not salt water marine environments.

Re: Titanic tourist submersible goes missing with search under way

#588

let me be naive : carbon fiber composite is about tensile stength, not compression strength ? what happens in the ocean ? compression...

The fibers are strong in both tension and compression (not equally so, see figure 1: http://home.iitk.ac.in/~mohite/axial_compressive.pdf), but in compression their aspect ratio is very very very large so they buckle instantly… unless you glue them together so each strand is supporting the ones near it and the effective aspect ratio is much less. Aside from fiber wound pressure bottles just about any real world composite structure will experience bending forces which will put the top in compression and the bottom in tension. The designer might need to reinforce the compressive side more, depending on the application (e.g. if designing for stiffness the strength might end up with considerable margin for both tension and compression).

Re: Titanic tourist submersible goes missing with search under way

#589

Earlier quoted context omitted.

The Baha'i religion is pure free thought. Truly admirable. Pity it didn't catch on (and probably never will).

You may end up surprised, its a religion which handles meeting modern world and its values much better than any other major religion (maybe apart from Buddhism, if you consider it religion per se). Sad to see its cradle, Persia, to go full hatred on it. Interestingly, they found their safe haven in Israel. I hope main reason wasn't to just insult arch enemy, but rather simple tolerance.

The were repeatedly exiled by persian authorities and ultimately sent to a prison city in Israel (Akka), so it wasn't their direct choice they ended up there. I guess the political situation back then was different. Abdul-Baha from the article above was with them, and His father Baha'u'llah as well

https://en.wikipedia.org/wiki/Bah%C3%A1%CA%BCu%27ll%C3%A1h#F...

That said they would not consider their oppressors as their enemies but rather that the oppressor is hurting themselves more than their victim by depriving themselves of actual happiness

Here is a letter Abdul-Baha's father wrote to the persian Shah while in prison. It is just incredible to say the least

https://www.bahai.org/library/authoritative-texts/bahaullah/...

Re: Titanic tourist submersible goes missing with search under way

#590

Earlier quoted context omitted.

The door can still be designed to open outward and also able to be unlatched from the inside: those aren’t mutually exclusive properties.

It needs to remain perfectly watertight at over 5000psi or everyone dies. That design constraint probably eliminates most clever latch designs.

This is usually done with a plug hatch and it's not that complex. The Alvin submersible has one and it's from 1964.
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