Outside Topic OT: Underwater topic

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OT: Underwater topic - gailtate - 06-21-2023

Re the latest Billionaire Bucket-List Thrills-and-Chills Bragging Rights: Who picks up the tab for the Coast Guard's soon-to-be futile rescue mission? I can't imagine the resources allocated on this caper. All due respect to the CG, of course, but I want to believe that the aggregate net worth of the hapless passenger list might be tapped, somehow/someway. Anyone? Anyone?

RE: OT: Underwater topic - Goose - 06-21-2023

(06-21-2023, 01:54 PM)gailtate Wrote: Re the latest Billionaire Bucket-List Thrills-and-Chills Bragging Rights: Who picks up the tab for the Coast Guard's soon-to-be futile rescue mission? I can't imagine the resources allocated on this caper. All due respect to the CG, of course, but I want to believe that the aggregate net worth of the hapless passenger list might be tapped, somehow/someway. Anyone? Anyone?

The lifesaving and rescue services performed/provided by the Coast Guard have always been delivered without regard to the ability of the target to pay. The funding was assumed to be provided by the taxpayer for the "common good". The cost of searching for a small boat that has issued a "mayday" call is often many. many times more than the worth of the vessel or the ability of those (hopefully) rescued to pay. There have been efforts to create licensing fees that would help "special risk" activities defer the extra costs they require of the Coast Guard to be supported by the users. Generally, that hasn't worked because the potential costs are difficult to estimate and the worst-case costs are enormous. In theory, you could attempt to force such activities to buy insurance policies for their operations that the Coast Guard could "tap into" in the event of a disaster, but nobody will write such policies. The potential liability is too high to make it economically viable. This is very unlikely to change.

RE: OT: Underwater topic - CompSci87 - 06-21-2023

This thread isn't all that political IMO, at least not partisan political, but it's already been reported as political. So it will get a very short leash before being closed.

RE: OT: Underwater topic - gailtate - 06-21-2023

(06-21-2023, 03:00 PM)Goose Wrote:
(06-21-2023, 01:54 PM)gailtate Wrote: Re the latest Billionaire Bucket-List Thrills-and-Chills Bragging Rights: Who picks up the tab for the Coast Guard's soon-to-be futile rescue mission? I can't imagine the resources allocated on this caper. All due respect to the CG, of course, but I want to believe that the aggregate net worth of the hapless passenger list might be tapped, somehow/someway. Anyone? Anyone?
The lifesaving and rescue services performed/provided by the Coast Guard have always been delivered without regard to the ability of the target to pay. The funding was assumed to be provided by the taxpayer for the "common good". The cost of searching for a small boat that has issued a "mayday" call is often many. many times more than the worth of the vessel or the ability of those (hopefully) rescued to pay. There have been efforts to create licensing fees that would help "special risk" activities defer the extra costs they require of the Coast Guard to be supported by the users. Generally, that hasn't worked because the potential costs are difficult to estimate and the worst-case costs are enormous. In theory, you could attempt to force such activities to buy insurance policies for their operations that the Coast Guard could "tap into" in the event of a disaster, but nobody will write such policies. The potential liability is too high to make it economically viable. This is very unlikely to change.

Noted, thx. So once again we're seeing our tax dollars at work. In vain, this time. What remains of Titan, if anything, probably resembles large, empty tube of toothpaste.

RE: OT: Underwater topic - Leftcoast - 06-21-2023

I grew up near Yosemite and had many friends in various official and unofficial S&R roles so I am familiar with the very similar problem with thrill/adrenaline sports at National Parks - Base jumping, hang-gliding, mountain climbing, ultra class white water rafting, heli-skiing extreme slopes.

Search and rescue activities are expensive and enthusiasts resist attempts to curtail their sports. Sometimes the results are tragic. (I decided to edit out a well known example from base jumping off El Capitan in protest of the parks prohibition but it's easily found with Google.)

(Feel free to delete CompSci if this is "political". Not my intent and my feelings will not be hurt)

/Lefty

RE: OT: Underwater topic - newguy - 06-21-2023

i feel bad for that 19-yr-old kid.
i bet his mother is angry with his father (who is also on the vessel) for taking their son on that excursion.

RE: OT: Underwater topic - M T - 06-21-2023

A real tragedy.

Compassion abounds.

RE: OT: Underwater topic - OutsiderFan - 06-22-2023

The comically terrible corporate news business has quite the shiny object to attract attention with this impossibly stupid story of hubris and excess, doesn’t it?

Why anyone cares about it is beyond my comprehension. There are millions of more important truths to report and many people going through far worse. But I guess uncovering those stories costs money the news business would rather not spend. Hard to think of too many types of enterprises less interested in the quality of their product.

Breathlessly reporting on this silliness as if the empty soul of News Business Inc. actually gives AF about the people involved insults well developed intelligence. But that isn’t nearly as bad as trying to profit off the misery of the poor bastards involved and their families by trying to monetize the emotions of those manipulated into caring about it.

RE: OT: Underwater topic - 82lsju - 06-22-2023

(06-21-2023, 05:29 PM)Leftcoast Wrote: Search and rescue activities are expensive and enthusiasts resist attempts to curtail their sports. Sometimes the results are tragic. (I decided to edit out a well known example from base jumping off El Capitan in protest of the parks prohibition but it's easily found with Google.)

/Lefty

we arrived in Yosemite that day with my Mom (her only visit to the park) and were wondering what all the activity was about, we found out later what happened.

an interesting read on this topic is "Off the Wall: Death in Yosemite". One of the takeaways from the book is that if you are not in the demographic of males in their teens and twenties the likelihood of dying in the park goes down significantly....which should not be a surprise to anyone....

RE: OT: Underwater topic - newguy - 06-22-2023

just out of curiosity, are there any engineers here with knowledge of the advantages and disadvantages of constructing deep-sea submersibles with carbon composite materials?

RE: OT: Underwater topic - Nan3cy - 06-22-2023

(06-22-2023, 06:19 PM)newguy Wrote: just out of curiosity, are there any engineers here with knowledge of the advantages and disadvantages of constructing deep-sea submersibles with carbon composite materials?

I’m absolutely not an engineer, but from what I read, the first and most basic mistake was not getting the carbon-based material tested to see if it would resist the deep-sea pressure. Apparently it didn’t.

RE: OT: Underwater topic - jacket3ree - 06-22-2023

The death of 5 billionaires willing to die in search of adventure is no more or less tragic than today's deaths of some 160,000 souls worldwide. But it is more interesting, so CNN et al will fixate on it until the next kid is found down a well.

Presently I'm camped out at a very large construction site where we don't use carbon fiber anything, relying instead on codified materials like concrete, steel, and dirt. (Yeah, dirt isn't so codified - I guess that's our bleeding edge.) If something hasn't been in use exposed to the elements, especially UV light, for a few decades, we won't design with it.

We have a real diverse cast of characters from all walks of life out here on the daily (and weekends) building this thing. Some of us talked about this incident over lunch. We even have a genuine former USN submariner. He explained what likely happened while telling us none of us know shit. A quick implosion and instant, painless death. We then learned all the things he went through while trapped in a steel can full of radioactive material, fire hazards, and dickheads. Oh, the alternative of slowly suffocating is definitely neither quick nor painless. Universal reaction: 'The rich get to die easy too, don't they?"

I haven't really gotten into this, but it sounds like these adventurers weren't taking the first Airbus; they were X15 test pilots. It would be interesting to read the waivers.

RE: OT: Underwater topic - 82lsju - 06-23-2023

(06-22-2023, 11:18 PM)jacket3ree Wrote: I haven't really gotten into this, but it sounds like these adventurers weren't taking the first Airbus; they were X15 test pilots. It would be interesting to read the waivers.

what previous passengers had to say about the waiver

Quote:A former passenger on the missing Titanic tourist submersible said he prepared himself to never get off the vessel after signing a waiver which listed 'three ways to die on page one'.
...
The disclaimer, read out by CBS correspondent David Pogue, read: “This experimental submersible vessel has not been approved or certified by any regulatory body, and could result in physical injury, disability, emotional trauma, or death.”

https://inews.co.uk/news/world/experimental-sub-waiver-missing-titanic-tourists-2423390

RE: OT: Underwater topic - newguy - 06-23-2023

(06-22-2023, 11:18 PM)jacket3ree Wrote: The death of 5 billionaires willing to die in search of adventure is no more or less tragic than today's deaths of some 160,000 souls worldwide. But it is more interesting, so CNN et al will fixate on it until the next kid is found down a well.

Presently I'm camped out at a very large construction site where we don't use carbon fiber anything, relying instead on codified materials like concrete, steel, and dirt. (Yeah, dirt isn't so codified - I guess that's our bleeding edge.) If something hasn't been in use exposed to the elements, especially UV light, for a few decades, we won't design with it.

We have a real diverse cast of characters from all walks of life out here on the daily (and weekends) building this thing. Some of us talked about this incident over lunch. We even have a genuine former USN submariner. He explained what likely happened while telling us none of us know shit. A quick implosion and instant, painless death. We then learned all the things he went through while trapped in a steel can full of radioactive material, fire hazards, and dickheads. Oh, the alternative of slowly suffocating is definitely neither quick nor painless. Universal reaction: 'The rich get to die easy too, don't they?"

I haven't really gotten into this, but it sounds like these adventurers weren't taking the first Airbus; they were X15 test pilots. It would be interesting to read the waivers.

I used to work as a civilian at an army post in Maryland, alongside other civilians, as well as soldiers, Air Force officers, Marines, and former submariners.

Submariners are a colorful lot. It was quite an experience working with them.

RE: OT: Underwater topic - pefloresjr - 06-23-2023

One question I have for the engineers here is based on something James Cameron said about carbon fiber. He said carbon fiber composites have great strength and rigidity but no compression strength. Does anyone know more about this? It seems that OceanGate had several successful trips to the Titanic and other deep sea locations. Is it possible that the fiber weakened over time like metal fatigue? Supposedly, there were sensors on the hull designed to give a warning about weakness that was supposed to allow the pilot a chance to resurface. One commenter said that by the time the sensor went off, it would already be too late to do anything about it. I have no knowledge to evaluate the legitimacy of those claims. Any expert opinions?

Cheers,
Pete F.

RE: OT: Underwater topic - g1313 - 06-23-2023

(06-22-2023, 06:19 PM)newguy Wrote: just out of curiosity, are there any engineers here with knowledge of the advantages and disadvantages of constructing deep-sea submersibles with carbon composite materials?

Just an educated layperson, but have been following this pretty closely out of morbid curiosity.

From what I gather, the main advantage in this use case is carbon fiber is lightweight compared to steel or titanium. That's great when you are shooting something into the air or space, but typically not as necessary for sinking to the bottom of the ocean. The real benefit here is having a lighter weight vessel fits on a smaller boat because you don't need a giant crane to launch it.

Traditionally carbon fiber seems more known for tensile strength (it won't break when you pull it apart) and is not considered optimal for strength under compression. From what I have read it is possible to be used for compression with the correct design, but it is relatively novel and perhaps not well studied.

The big drawback seems to be that it is hard to inspect carbon fiber for fatigue in a non-destructive way, and that difficulty increases with the thickness (in this case five inches). Also, the design of the Titan is a carbon fiber cylinder with titanium end caps, so the interface between the two materials is a potential failure point.

Finally, to the original point on the cost to society of a rescue effort, this seems like a relative drop in the bucket, I'm sure it is dwarfed by the aggregate cost of other fun, less risky but more common activities (skiing, playing sports, etc). There is already a big disincentive (risking your own life) so I don't think there is some big moral hazard.

RE: OT: Underwater topic - dabigv13 - 06-23-2023

[Tweet]https://twitter.com/nycsouthpaw/status/1672289491153764359?s=20[/tweet]

Good interview with James Cameron where he goes over some of the problems with carbon fiber designs. He speculates that they likely heard the hull cracking in their last moments and tried an unsuccessful emergency ascent. Horrific.

They probably never felt or recognized the final implosion however. From analysis of the Argentinian submarine ARA San Juan that had a similar event a few years ago, the estimation was that the implosion took about 40 milliseconds. This vessel was even deeper and pressures would have been even higher.

[Tweet]https://twitter.com/Shippers999/status/1672239686708756483?s=20[/tweet]

RE: OT: Underwater topic - Hurlburt88 - 06-23-2023

I believe carbon fiber composites can also suffer from delamination as the primary fatigue mechanism. Really key to not miss a trick in a design like this.

On a lighter note, classmate of mine for senior mech eng project designed and built a small sub. Prof did not really expect the group would get as far as they did, and the day before they were to test in Lake Lag she nixed it. IIRC, they ended up testing in Lake Tahoe after graduation--successfully. He laughs about it to this day. And for the curious, steel was the key material.

RE: OT: Underwater topic - CowboyIndian - 06-23-2023

(06-22-2023, 09:27 PM)Nan3cy Wrote: I’m absolutely not an engineer, but from what I read, the first and most basic mistake was not getting the carbon-based material tested to see if it would resist the deep-sea pressure. Apparently it didn’t.

My understanding is that the carbon fiber worked for a few dives but over time became "fatigued". That's according to James Cameron, director of "Titanic" and a veteran of many dives in the deep, including the Mariana Trench. Cameron noted that the fact that there were mixed materials (carbon and resin) made it ultimately unsafe.

RE: OT: Underwater topic - rudruff - 06-23-2023

Spent three years on an LA class after graduating.

The other issue you have is checking for flaws after a successful dives in any submersible. Just because something worked the last time does not mean it wasn't weakened. We had dozens of sailors with with dozens of checklists before we submerged and certainly weren't dealing with the pressure issues of operating at that depth.

I doubt they knew anything before it was over.