Sub thing going on is fascinating

[mbasic]

I mean .... after reading up on the sub that imploded, and reading up on DeepSea Challenger ... there's not much left to say.

That Titan thing was a piece of utter shit.

How did these five people talk themselves into it? .... I get that the Pakistani guy and his kid could get Jim Jones'ed into signing up and duped into thinking its safe. But the other three all thought this was a good worthy craft for the task at hand? Some kind of group think thing going on?

It makes more sense this is an elaborate life insurance scam, and/or these five guys REALLY wanted to get away from their wives or something (the sub only went 100 ft deep off to another recovery craft or something .... the pieces they found were planted weeks ago). I believe that over "men of science" strapping in to that untested piece of garbage.

[Renascent]

... there's not much left to say.

Pretty much.

"Play stupid games," and all that.

Imagine what kind of warped, conceited asshole one has to be to hand over a quarter of a mil to drag their kid along for such an authentic "thrill."

[mbasic]

I guess doing some reading, clicking, skimming ....
... as Elon Musk would say: "It's not that hard".

The news keeps talking about 13000 ft deep and 6000 PSI pressure. That's actually not a lot of pressure. Our hydraulic cylinders on our equipment operate at about 5000 PSI. The walls of the barrel are only 1/4" thick .... if that really. Millions of duty and heat cycles. Huge hydraulic cylinders on mining equipment, their barrels aren't much thicker and the bore increases. And this stuff (I'm using) is comparative garbage compared to 'space age' materials.

I understand a big sub is different in many ways, .... but we sent Bathyescapes down to the Marianas Trench back in the 1960's.

The hull is the last thing that should have failed (or that glass portal/dome thingy).

Its so easy, and egg can do it.

[mbasic]

Imagine what kind of warped, conceited asshole one has to be to hand over a quarter of a mil to drag their kid along for such an authentic "thrill."

maybe you saw this (recent) .... or not yet?

https://www.yahoo.com/news/19-old-titan ... 14349.html

"Azmeh Dawood — the older sister of Pakistani businessman Shahzada Dawood — told NBC News that her nephew, Suleman, informed a relative that he "wasn't very up for it" and felt "terrified" about the trip to explore the wreckage of the Titanic."

[chrisd]

I guess doing some reading, clicking, skimming ....
... as Elon Musk would say: "It's not that hard".

The news keeps talking about 13000 ft deep and 6000 PSI pressure. That's actually not a lot of pressure. Our hydraulic cylinders on our equipment operate at about 5000 PSI. The walls of the barrel are only 1/4" thick .... if that really. Millions of duty and heat cycles. Huge hydraulic cylinders on mining equipment, their barrels aren't much thicker and the bore increases. And this stuff (I'm using) is comparative garbage compared to 'space age' materials.

I understand a big sub is different in many ways, .... but we sent Bathyescapes down to the Marianas Trench back in the 1960's.

The hull is the last thing that should have failed (or that glass portal/dome thingy).

Its so easy, and egg can do it.

I think it's question of scale. The pressure differential of deformation of a curve is proportional to the cubed sine of the square of the hypoteneuse or something.

Anyway, what I do know is that one atmosphere is enough to implode a tube. That's why the hyperloop is such a comical failure. Vacuum tubes work fine for small stuff, up to a couple of inches across, beyond that the tube has to be so strong it's hard to build. Likewise 6000psi might be easy to deal with when you're dealing with inches, but when the object is a few yards long, it's harder.

Given that this thing appears to have been put together with gewgaws and bittybobs, I wouldn't be surprised if the basic design hadn't been scaled up from a toy sub from a cornflakes packet and not put through much more than an immersion test like you do to test watches.

There already proper submersibles that can do this kind of thing, albeit rather risky. Why not just use one of them ?

[mbasic]

I guess doing some reading, clicking, skimming ....
... as Elon Musk would say: "It's not that hard".

The news keeps talking about 13000 ft deep and 6000 PSI pressure. That's actually not a lot of pressure. Our hydraulic cylinders on our equipment operate at about 5000 PSI. The walls of the barrel are only 1/4" thick .... if that really. Millions of duty and heat cycles. Huge hydraulic cylinders on mining equipment, their barrels aren't much thicker and the bore increases. And this stuff (I'm using) is comparative garbage compared to 'space age' materials.

I understand a big sub is different in many ways, .... but we sent Bathyescapes down to the Marianas Trench back in the 1960's.

The hull is the last thing that should have failed (or that glass portal/dome thingy).

Its so easy, and egg can do it.

I think it's question of scale. The pressure differential of deformation of a curve is proportional to the cubed sine of the square of the hypoteneuse or something.

Anyway, what I do know is that one atmosphere is enough to implode a tube. That's why the hyperloop is such a comical failure. Vacuum tubes work fine for small stuff, up to a couple of inches across, beyond that the tube has to be so strong it's hard to build. Likewise 6000psi might be easy to deal with when you're dealing with inches, but when the object is a few yards long, it's harder.

yards or inches it doesn't matter that much. the cross-section of that sub isn't that much different than a huge cylinder on a mining dump or something. Those cylinder tubes are also as thick as they as because the cylinder is also dealing with massive dynamic loads of whatever it is supporting or moving....its a structural member as well as a pressure vessel. Not exploding is probably the easy part. I know we are talking inward vs outward pressure .... but 6,000 PSI isn't a lot.
I think the rub is coming up with something thats not overly heavy for "buoyancy systems" to still work .... anyone can just throw excessive metal at the problem. The two domed end caps were solid titanium half-spheres tho ...

As far as the hyper loop thing. The problem there, is not only structural ... but the amount of time and energy it would take to suck out a tube several miles long is fucking ridiculous. Even a partial vacuum would be silly.

[Renascent]

Imagine what kind of warped, conceited asshole one has to be to hand over a quarter of a mil to drag their kid along for such an authentic "thrill."

maybe you saw this (recent) .... or not yet?

https://www.yahoo.com/news/19-old-titan ... 14349.html

"Azmeh Dawood — the older sister of Pakistani businessman Shahzada Dawood — told NBC News that her nephew, Suleman, informed a relative that he "wasn't very up for it" and felt "terrified" about the trip to explore the wreckage of the Titanic."

Yeah, I read about that sometime this morning.

Admittedly I wasn't too interested in the whole story, but then I had to sit through a "Moment of Silence" in a Zoom meeting the other day and wondered if they were dead yet.

Not sure if this is on topic with the spirit of the thread, but I can't really muster any sympathy for anyone involved besides the nineteen-year-old.

If one wants to go gliding from the top of the Eiffel Tower in a homemade wingsuit, or riding off to Jupiter in a life-size bottle rocket... well, Godspeed. Guilting your kid into becoming another likely casualty is probably more of a testament to one's personage than one's apparent sense of adventure.

As for the rest of the crew, I guess being a "learn'd astronomer," so to speak, doesn't make a person immune to stupidity. Exploration is cute, but so is common sense.

"Look on my Works, ye Mighty, and despair!"

Yea.

[dw]

Lol @ the moment of silence.

I guess if your work for a submarine factory or something that would make sense... otherwise why is this the one thing in the world today that requires public expression of mourning?

[Renascent]

... otherwise why is this the one thing in the world today that requires public expression of mourning?

Because it's the kind of thing that brings people together.

Like global warfare or championships. Or beer.

[hector]

... otherwise why is this the one thing in the world today that requires public expression of mourning?

Because it's the kind of thing that brings people together.

Like global warfare or championships. Or beer.

I think our wars are dumb and I don’t drink beer. This explains why I’m a misanthrope. All makes sense now.

James Cameron goes deep in a sub he helped design. There are ways for rich people to do this safely it seems. I guess these people got scammed.

[mgil]

Tensile strength is different than compressional strength.

I believe this rig went to a similar depth prior. The issue seems to be that the cycling of the hull wasn’t fully considered and/or inspected.

Lots of bad business decisions being made here.

[mbasic]

Tensile strength is different than compressional strength.

That bullshit sounds like its straight outta SuperTraining.

There is only general strength.

[Philbert]

Tensile strength is different than compressional strength.

That bullshit sounds like its straight outta SuperTraining.

There is only general strength.

Hydraulic cylinder walls are in tension, while submersible walls are in compression, as Mgil said. The difference is that in compression any deformity, however slight, creates a massive local stress point, inviting failure. Carbon fiber composites are also brittle, more so at 40 degrees than at typical room temperature. The utility of carbon fiber is, as you suggested, its light weight, allowing for simpler flotation systems to achieve neutral buoyancy. One of the most famous true deep sea submersibles used a large tank of gasoline for flotation to balance the massive steel shell.

[mbasic]

Tensile strength is different than compressional strength.

That bullshit sounds like its straight outta SuperTraining.

There is only general strength.

Hydraulic cylinder walls are in tension, while submersible walls are in compression, as Mgil said. The difference is that in compression any deformity, however slight, creates a massive local stress point, inviting failure. Carbon fiber composites are also brittle, more so at 40 degrees than at typical room temperature. The utility of carbon fiber is, as you suggested, its light weight, allowing for simpler flotation systems to achieve neutral buoyancy. One of the most famous true deep sea submersibles used a large tank of gasoline for flotation to balance the massive steel shell.

You missed the joke. In the book SuperTraining, they define seven different types of strength: ultimate strength, speed strength, explosive strength, etc. Rip always balked at this idea.

My point was about the hydraulic cylinder example was: 1-these are rather pedestrian pressures that are delt with all the time in regular ol' industry. 2-same with metal, known stress tolerances, duty cycles, can inspect, x-ray, etc, model it etc.....we went to the bottom of Marianas Trench clear back in 1960 in a VERY asymmetrical looking metal can. I Laugh Out Loud at your differential pressure stresses concerns....it's a thing, but it's also 2023. It's not like we're sending a probe into a gaseous giant planet (Saturn) or something.

It appear carbon fiber and the duty cycle thing is probably what did "it". I guess those Virgin clowns were going to make a deep submersible with carbon fiber hull too....rub was it was disclosed ahead of time they would only certify it for one trip and one trip only for the "cycle" reasons.

Or, it also could've been the titanium adapter rings (for the TI half domes).....looks like those were JB Welded onto the fiber tube .... a lot of dissimilar materials there all right "in a row".

Or the OBVIOUS clear plastic dome window....was grossly underrated for the task at hand.

[mgil]

The Trieste may look asymmetric but what you’re seeing are the ballast tanks. The actual bathysphere that those two dudes sat in was a sphere and only about 1.5m or something in diameter. The porthole on that rig was acrylic glass, so also a plastic. However, properly engineered (although it did crack going down to Challenger Deep).

There are two main lessons here:

1. It’s difficult to over-engineer things when the operational environment is harsh.

2. Safety inspections are necessary and issues must be resolved.

[Renascent]

1. It’s difficult to over-engineer things when the operational environment is harsh.

With that said, I'll ask a question out of genuine curiosity:

Assuming all the plebian reporting is true (or I've fallen for it), why the fuck would someone agree to pilot a submersible with a wireless Logitech controller?

I have two (!) Logitech gaming controllers that I use every blue moon when:

1) I'm in the mood to lose with little consequence.

2) I wanna play Fire Pro Wrestling Returns, and -- given the scripted and predetermined nature of theatrical "sport" -- it makes no difference whether I win or lose, as long as I go down in a blaze of face-kicking glory.

But since there is no face-kicking glory in being crushed to death as one approaches the floor of the ocean in a propietary shitbox, why would an engineer consider a Logitech product gaming controller to be a viable steering apparatus?

[mgil]

1. It’s difficult to over-engineer things when the operational environment is harsh.

With that said, I'll ask a question out of genuine curiosity:

Assuming all the plebian reporting is true (or I've fallen for it), why the fuck would someone agree to pilot a submersible with a wireless Logitech controller?

I have two (!) Logitech gaming controllers that I use every blue moon when:

1) I'm in the mood to lose with little consequence.

2) I wanna play Fire Pro Wrestling Returns, and -- given the scripted and predetermined nature of theatrical "sport" -- it makes no difference whether I win or lose, as long as I go down in a blaze of face-kicking glory.

But since there is no face-kicking glory in being crushed to death as one approaches the floor of the ocean in a propietary shitbox, why would an engineer consider a Logitech product gaming controller to be a viable steering apparatus?

There are tales of Xbox controllers being used on USA submarines. However, these have limited impact and there are backups. Things that actuate actual control surfaces are analog.

I get that to control the piloting of this ship, a basic controller would likely work. Using a cheap one seems, well, cheap, but maybe that was the easiest to integrate with the system software?

I don’t know what the control surfaces and propulsion systems were on this craft, but they might’ve been simple enough to control with that controller.

That being said a real console and controllers would probably have been a good idea.

[Renascent]

1. It’s difficult to over-engineer things when the operational environment is harsh.

With that said, I'll ask a question out of genuine curiosity:

Assuming all the plebian reporting is true (or I've fallen for it), why the fuck would someone agree to pilot a submersible with a wireless Logitech controller?

I have two (!) Logitech gaming controllers that I use every blue moon when:

1) I'm in the mood to lose with little consequence.

2) I wanna play Fire Pro Wrestling Returns, and -- given the scripted and predetermined nature of theatrical "sport" -- it makes no difference whether I win or lose, as long as I go down in a blaze of face-kicking glory.

But since there is no face-kicking glory in being crushed to death as one approaches the floor of the ocean in a propietary shitbox, why would an engineer consider a Logitech product gaming controller to be a viable steering apparatus?

There are tales of Xbox controllers being used on USA submarines. However, these have limited impact and there are backups. Things that actuate actual control surfaces are analog.

I get that to control the piloting of this ship, a basic controller would likely work. Using a cheap one seems, well, cheap, but maybe that was the easiest to integrate with the system software?

I don’t know what the control surfaces and propulsion systems were on this craft, but they might’ve been simple enough to control with that controller.

That being said a real console and controllers would probably have been a good idea.

Interesting.

I kinda figured it might be safer and/or wiser to reverse-engineer one's own controller with better parts (especially if you have any experience with a Logitech controller in an environment with lower stakes), though I gather that particular design feature likely wasn't a factor in the failure of the sub.

[JonA]

I kinda figured it might be safer and/or wiser to reverse-engineer one's own controller with better parts (especially if you have any experience with a Logitech controller in an environment with lower stakes), though I gather that particular design feature likely wasn't a factor in the failure of the sub.

Reliability is sometimes easier to achieve through redundancy. Cheap controllers means they probably had a bunch of spares, the likely hood that they'd all fail is much, much less.

[Renascent]

I kinda figured it might be safer and/or wiser to reverse-engineer one's own controller with better parts (especially if you have any experience with a Logitech controller in an environment with lower stakes), though I gather that particular design feature likely wasn't a factor in the failure of the sub.

Reliability is sometimes easier to achieve through redundancy. Cheap controllers means they probably had a bunch of spares, the likely hood that they'd all fail is much, much less.

Hmm.

Makes sense, but I was a little surprised that a submersible pilot would be fine with dealing with analog stick drift, assuming it's as much of a problem in that scenario as it is when using the controller for its marketed purpose.