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Titanic tourist submersible goes missing with search under way

bbc.com

41–50 of 649 posts

Re: Titanic tourist submersible goes missing with search under way

#41

“The Boston Coast Guard […]” As in the American city of Boston? If so, why are they the first responders here?

the wreckage of the Titanic is in their area of responsibility:

https://sarcontacts.info/contacts/rcc-boston-1st-district-57...

Re: Titanic tourist submersible goes missing with search under way

#42

“The Boston Coast Guard […]” As in the American city of Boston? If so, why are they the first responders here?

I was curious too.

> Contacted by CBS News, the Canadian Coast Guard said the rescue operation was being managed by the Boston Regional Coordination Center, and a map showing jurisdictions for the various coastal search and rescue agencies off the North American coast shows the location of the Titanic wreck within the Boston center's area of responsibility.

https://www.cbsnews.com/news/titanic-submarine-missing-rescu... https://sarcontacts.info/contacts/rcc-boston-1st-district-57...

Re: Titanic tourist submersible goes missing with search under way

#43
post #42

“The Boston Coast Guard […]” As in the American city of Boston? If so, why are they the first responders here?

I was curious too. > Contacted by CBS News, the Canadian Coast Guard said the rescue operation was being managed by the Boston Regional Coordination Center, and a map showing jurisdictions for the various coastal search and rescue agencies off the North American coast shows the location of the Titanic wreck within the Boston center's area of responsibility. https://www.cbsnews.com/news/titanic-submarine-missing-rescu…

I always assumed the Titanic went down further north. Didn't know there were icebergs that far south.

Edit: they float there https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2...

Re: Titanic tourist submersible goes missing with search under way

#44

A CBS article identified this company’s sub as the one involved; https://twitter.com/OceanGateExped

Fascinating theyre relying on starlink for operations. I heard starlink was fairly unreliable from folks who have it in remote areas.

What better alternatives would they have in the middle of the ocean?

Re: Titanic tourist submersible goes missing with search under way

#45
post #30

This appears to be the vessel in question: https://oceangate.com/our-subs/titan-submersible.html Pressure hull made from titanium and carbon fiber, capable of diving to 4000m (13,000 ft). I recall that one reason SpaceX switched from carbon fiber to stainless steel pressure vessels (fuel tanks) was the difficulty of detecting structural flaws. Can any engineers comment on whether that task is easier for a vessel expo…

The structural problems for space vessels vs submersibles I might believe to be quite different.

In space the main issue is containing internal pressure - so the skin is all in tension.

While a submersible the pressure is from without - so the skin is all in compression.

Re: Titanic tourist submersible goes missing with search under way

#46
post #30

This appears to be the vessel in question: https://oceangate.com/our-subs/titan-submersible.html Pressure hull made from titanium and carbon fiber, capable of diving to 4000m (13,000 ft). I recall that one reason SpaceX switched from carbon fiber to stainless steel pressure vessels (fuel tanks) was the difficulty of detecting structural flaws. Can any engineers comment on whether that task is easier for a vessel expo…

The structural problems for space vessels vs submersibles I might believe to be quite different. In space the main issue is containing internal pressure - so the skin is all in tension. While a submersible the pressure is from without - so the skin is all in compression.

Also of note, the pressure differences are much higher in submersibles.

Re: Titanic tourist submersible goes missing with search under way

#47
post #30

This appears to be the vessel in question: https://oceangate.com/our-subs/titan-submersible.html Pressure hull made from titanium and carbon fiber, capable of diving to 4000m (13,000 ft). I recall that one reason SpaceX switched from carbon fiber to stainless steel pressure vessels (fuel tanks) was the difficulty of detecting structural flaws. Can any engineers comment on whether that task is easier for a vessel expo…

I'm not really an engineer (general hobbyist, former chemist) but I have built and worked with pressure and vacuum vessels.

Positive pressure (tank vs exterior) is much easier to deal with than negative pressure (vacuum vessel at 1 atm, or bathyscape with 1 atm inside and high pressure exterior). In positive pressure, your stress is mostly in the hoop mode, which is stable. This is why aluminum cans can be so thin. In negative pressure vessels, you have a buckling mode, which is inherently unstable. As soon as it goes, it goes all at once.

I've had a 2L glass vacuum flask implode on me. There is no warning. All it takes is a tiny defect, and once you hit a certain pressure delta, kaboom. Composite is similar in that it's mostly brittle failure vs ductile. I've also imploded a 55 gallon steel vessel. That goes a lot more gradually (though still fast) - maybe enough to detect and abort the trip.

The other main advantage of steel vs composite is you can inspect with X-ray imaging to find defects.

Re: Titanic tourist submersible goes missing with search under way

#48
post #5

I had no idea that "tourists" visited Titanic. Is this the new thing after Everest became crowded?

[flagged]

That's a particularly crass thing to say about someone while their life is in jeopardy.

>Did it not occur to anyone that it might be a bad idea? It's hard to be sympathetic in the face of such arrogance

The company advertises the safety of their submersible and an active suite of sensors to detect and prevent failures.

Re: Titanic tourist submersible goes missing with search under way

#49

Skimming the website, I assume this submersible is using electromagnetically attached drop-weights so that if anything goes wrong and power is lost, the weights drop off and the submersible floats up to the surface again? And 96 hours of life support sounds good, but unless there is another submersible nearby that can dive down, find them AND attach a line, the number of hours of life support will be irrelevant. Of c…

Some articles I found suggest that a trip was 8 hours to get there and back. Another mentioned being in the sub for 12 hours. I'm guessing it's a 4 hour trip each way and then they spend a number of hours checking the wreckage.

The wreckage site is around 370 miles from Newfoundland, Canada.

Seems like the rescue effort could be unfolding over days.

Re: Titanic tourist submersible goes missing with search under way

#50

Earlier quoted context omitted.

[flagged]

That's a particularly crass thing to say about someone while their life is in jeopardy. >Did it not occur to anyone that it might be a bad idea? It's hard to be sympathetic in the face of such arrogance The company advertises the safety of their submersible and an active suite of sensors to detect and prevent failures.

Crass but maybe other rich people will also get hold of this sentiment and will avoid doing stupid stuff like this in the future.

Also, they were there visiting a place filled with dead and probably long decomposed people, can’t say I’m very sympathetic.

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