Technical Analysis on Titan Sub (Titanic Sub)

[hutchphd]

I had to unfriend a guy I've known since high school because he was "giggling with glee" about the plight of these (as he calls them) "oligarchs" (one of whom was actually a nineteen-year-old lad). I want to go wash off the stink.

I had a similar experience although there was no glee. But there was a rush to make it a polemic.
I think the better lesson is that mixing carbon fiber with titanium is very tricky.

And apparently the Navy did report the implosion to the Coasties at the time.

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[berkeman]

And apparently the Navy did report the implosion to the Coasties at the time.

Ooo, link?

 

[hutchphd]

I saw it on the TV news I think. I will try to do better, but later.

 

[Baluncore]

I think the better lesson is that mixing carbon fiber with titanium is very tricky.

We know how tensile carbon fibre composite structures age when subjected to cyclic internal pressure, through aircraft construction.

The cyclic compression of composites composed of tensile carbon fibres
is a different problem. Ageing of the material will follow a different process that involves crushing the filler. Significant bending must take place before the tensile fibres can again come into play at high external pressures. That deflection asymmetry is the weak point of a submarine hull.

 

[berkeman]

I saw it on the TV news I think. I will try to do better, but later.

No need, a quick Google search found many references to it. And because of the secrecy of the Navy sub-sea acoustic detection network, the exact details aren't being disclosed. But it's interesting that the USCG kept on searching anyway, even though they had the communications from the Navy early-on...

https://www.ktvu.com/news/titan-sub...us-navys-secret-acoustic-system-official-says

After detecting the sound of the implosion just 500 meters from the Titanic shipwreck, the Navy went back and analyzed its acoustic data.

It found that anomaly was "consistent with an implosion or explosion in the general vicinity of where the Titan submersible was operating when communications were lost," according to the senior Navy official.

The official spoke on condition of anonymity in order to discuss the U.S. Navy's sensitive acoustic detection system.

The official said the Navy passed on the information to the Coast Guard, which continued its search until the time had passed that the Titan would have sustained its passengers with breathable air.

 

[Vanadium 50]

A few points, in random order

• It's a submersible, not a submarine.
• There is more to acoustic undersea surveillance than a microphone and a guy with headphones.
• Sound can travel a long way underwater, but there are lots of sounds underwater. It is far from clear that had the mothership been listening they would have known what they are hearing.
• The same properties of water that cause sounds to sometimes carry much greater distances than average also cause sounds to sometimes carry much smaller distances than average also,
• At depth, the water pressure is about 5500 psi. That limits a lot of options.
• Shouldn't this be in GD?
• Major world governments spending a lot of time, money and effort listening to the oceans. They do not want their capabilities in this respect known to their potential future adversaries. So they are cagey about what they do and do not disclose.
• Once there is an implosion it no longer is "rescue". It is now "recovery" and is much less time-critical.

 

[berkeman]

It's a submersible, not a submarine.

I'm too lazy right now to go back to Google. What's the difference, no torpedos?

Shouldn't this be in GD?

Good point; I'll move it now.

 

[DaveC426913]

I had a similar experience although there was no glee.

It troubles me to have to clarify that "giggling with glee" is not surrounded by air quotes; those are bona fide quote marks - as in: I am quoting his words about how he's feeling.

 

[DaveC426913]

I'm too lazy right now to go back to Google. What's the difference, no torpedos?

Submarines are independently operable. They can get to and from their port of call (or whatever) unassisted.

The crew of this submersible can't even exit the craft on their own. They're bolted in. If they had surfaced safely and had been bobbing on the ocean all this time they'd still be dead by now, just inches from life-giving air.

 

[berkeman]

The crew of this submersible can't even exit the craft on their own. They're bolted in. If they had surfaced safely and had been bobbing on the ocean all this time they'd still be dead by now, just inches from life-giving air.

"Yeah, the hatch. We need a hatch with explosive bolts that we can open ourselves."

(Quiz Question -- what movie is that from?)

 

[hutchphd]

(Quiz Question -- what movie is that from?)

Mercury capsule.......Right Stuff?

 

[Slimy0233]

I read most of the comments (especially comments after the time Navy confirmed the implosion), I wonder how the crew might have died. Is it too graphic to ask someone? I mean, I as a puny human can't imagine such great forces. Would they have been compressed? Would they have lose consciousness instantly (painless death let's say)? Also, what would their bodies look like after the implosion?

 

[DaveC426913]

I read most of the comments (especially comments after the time Navy confirmed the implosion), I wonder how the crew might have died. Is it too graphic to ask someone? I mean, I as a puny human can't imagine such great forces. Would they have been compressed? Would they have lose consciousness instantly (painless death let's say)? Also, what would their bodies look like after the implosion?

This may be too graphic to be an appropriate topic of discussion here. I suggest, instead, that you Google Byford Dolphin Disaster to get a pretty good idea. Some articles are more detailed than others. YMMV.

 

[DaveC426913]

"... likely..."

 

[DaveE]

A few points, in random order

• It's a submersible, not a submarine.
• There is more to acoustic undersea surveillance than a microphone and a guy with headphones.
• Sound can travel a long way underwater, but there are lots of sounds underwater. It is far from clear that had the mothership been listening they would have known what they are hearing.
• The same properties of water that cause sounds to sometimes carry much greater distances than average also cause sounds to sometimes carry much smaller distances than average also,
• At depth, the water pressure is about 5500 psi. That limits a lot of options.
• Shouldn't this be in GD?
• Major world governments spending a lot of time, money and effort listening to the oceans. They do not want their capabilities in this respect known to their potential future adversaries. So they are cagey about what they do and do not disclose.
• Once there is an implosion it no longer is "rescue". It is now "recovery" and is much less time-critical.

If I may presume to add a bullet point:

• What the armed forces tell the news media may be very different than what they are saying on the bridge of the command vessel. It looks really bad if you give up to early, OTOH, and extra day or two of searching is both good PR and good training. Plus, they might not be 100% sure, maybe 90% sure isn't good enough.

 

[Baluncore]

OTOH, and extra day or two of searching is both good PR and good training.

It is important that a search be efficient and safe, without unnecessary additional risk. Every action is part of a training exercise, from which lessons will be learned. Log everything.
We are learning;
1. How long it takes to respond to a real submersible emergency.
2. Operational monitoring and communication requirements.
3. Things to avoid when constructing submersible vessels.
4. The applicability of external and independent transponders.

 

[Slimy0233]

View attachment 328281

"... likely..."

There's always a possibility that they were teleported by an alien UFO who foresaw this accident. :')

 

[Baluncore]

Maybe ChatGPT can be sued for not giving sufficient warning.
It had all the information necessary, and failed to act.

 

[Vanadium 50]

What's the difference,

A submarine does not require a support ship - it can execute its mission from pierside to pierside.,

This is a statement about what it can do, not what it does do. A submarine operating wuth the support of a surface shup does not become a submersible. Although I understand that the IAU wants to reclassify thm as "dwarf submarines", starting with the HMS Pluto.

 

[Vanadium 50]

the hatch....explosive bolts

Remember 5500 psi? You have 3 tons per square inch and a could hundred square inches and your "hatch" doesn't look like a hatch any more. It's a thick, semiconical metal plug. I have neither4 seen rgus one or pictures of it, but suspect that it is too heavy for muscle-power to move. It likely requires a special fixture to get it on and off.

Pyrotechnicl fasteners (what the 'pros' call explosive bolts) atr problematic - not only do they not have the necessary oomph. in what direction do they point?

 

[Rive]

in what direction do they point?

It's a frequent topic for 'gun fails' when the barrel is plugged by whatever reason - and suddenly all the oomph coming out on the other direction, yes...

I have neither4 seen rgus one or pictures of it, but suspect that it is too heavy for muscle-power to move.

Well, not really.

I think a more important issue is, that these subs are usually barely able to float so to safely open that can it's better to have it out of the water first.

 

[Vanadium 50]

A submarine that is neutrally buoyant in 4C water at 5500 psi will be negatively buoyant at 15C and 15 psi.

 

[hutchphd]

At depth the "fasteners" are irrelevant. This is in contradistinction to spacecraft (except Apollo block 1). For operations near the surface it is good to have your hatch securely fastened. At the surface it would be nice to be able to somehow extricate yourself although you probably would not wish to remove the entire front of your craft.
The cheapest solution is to bolt the spam into the can. It is a compelling argument.

 

[russ_watters]

I read most of the comments (especially comments after the time Navy confirmed the implosion), I wonder how the crew might have died. Is it too graphic to ask someone? I mean, I as a puny human can't imagine such great forces. Would they have been compressed? Would they have lose consciousness instantly (painless death let's say)? Also, what would their bodies look like after the implosion?

Using the slowest/easiest assumptions I can think of, the sub and everything in it would be obliterated in about 1/120th of a second. That's how long it would take for the window to traverse the length of the sub if smoothly accelerated up to the speed of sound (of water). Way too fast for human perception. But it likely collapsed from the sides, not the front and back. It's not unlike standing next to an explosion.

I also calculate the energy to be 32 kg of tnt, which unlike an explosion, all of it is directed towards the occupants.

 

[russ_watters]

At depth the "fasteners" are irrelevant. This is in contradistinction to spacecraft (except Apollo block 1). For operations near the surface it is good to have your hatch securely fastened. At the surface it would be nice to be able to somehow extricate yourself although you probably would not wish to remove the entire front of your craft.
The cheapest solution is to bolt the spam into the can. It is a compelling argument.

Looking at the DSV Alvin, it had a hatch on top, held in place by its weight and water pressure. It's unclear to me though if it can be opened from inside due to the weight.

But the Titan seems to have been more cheaply/simply engineered..

 

[Astronuc]

But it likely collapsed from the sides, not the front and back. It's not unlike standing next to an explosion.

If the personnel chamber is tubular/cylindrical rather than spherical, it would be much more prone to buckling, which I suspect is the mechanism of failure. Any amount of eccentricity, lack of concentricity, or nonuniformity in wall thickness increases risk.

Alvin and Trieste used spherical personnel chambers.
https://en.wikipedia.org/wiki/DSV_Alvin
https://en.wikipedia.org/wiki/Trieste_(bathyscaphe)
https://en.wikipedia.org/wiki/Trieste_II_(Bathyscaphe)

So it can be done right as evidenced by the visits to 20,000 ft (6096 m) depth down to 10,911 metres (35,797 ft) in the Challenger Deep of the Mariana Trench near Guam.

As I understand the news, the Titan may have imploded at around 9000 ft (2743 m), so it didn't even get to the Titanic depth. It suggests severe design deficiencies. The lack of certification is troubling. The reason for having regulations (mandatory rules in design and construction, followed by rigorous testing) and following them is precisely to prevent such tragedies.

 

[Vanadium 50]

obliterated in about 1/120th of a second.

And in that time the sound of the implosion would have traveled around 40 feet. So "why didn't the sonar operators do something?" has an easy answer - by the time the sound made it to them, there was nothing to be done.

 

[JLowe]

As I understand the news, the Titan may have imploded at around 9000 ft (2743 m), so it didn't even get to the Titanic depth. It suggests severe design deficiencies. The lack of certification is troubling. The reason for having regulations (mandatory rules in design and con

There aren't enough regulations in the world to persuade me to ride a private sub to 13k feet. It's hard to believe billionaires weren't aware of the risk regardless of what was claimed. I have sympathy, but this isn't something to be doing on a whim with a "trust me bro" CEO.

 

[Vanadium 50]

And if you ban this, do you also ban space tourism? Mountain climbing? (Who certifies those Sherpas anyway?) Swimming in the ocean? Eating fugu? Eating a high-cholesterol steak dinner? Anything that follows the phrase "Hey, hold my beer."? Where do you draw the line?

 

[BillTre]

There aren't enough regulations in the world to persuade me to ride a private sub to 13k feet. It's hard to believe billionaires weren't aware of the risk regardless of what was claimed. I have sympathy, but this isn't something to be doing on a whim with a "trust me bro" CEO.

I would seriously consider going in James Cameron's sub.