Titanic tourist sub goes missing

[dogmush]

I ran across this video today, which talks in a little more depth [heh] about the ways the thing could surface.  According to the vid, there was a Deadman Switch surfacing system in which sandbags would be dropped automatically by dissolving links after 10ish hours in salt water, giving Titan positive buoyancy.

That's actually pretty clever, and had they not had a catastrophic hull failure would have had them bobbing around on the surface by Sunday evening.  They also had droppable metal pipe ballast and an inflatable airbag to get to the surface.

Comfort of the hatch design aside, the real issue seems to be the single bias CF cylinder for the main hull.  Not a great material or shape for compressive forces, and even worse at repeated compressive forces.  I note from a quick glance across the various DSV's that hit 4000M depth, while they have many external hull shapes, they all use a pressure sphere as the manned compartment.  Probably an engineering clue there.

Here's the video:  https://www.youtube.com/watch?v=odLJ0dSLxmc

[MechAg94]

You could say it was a Titan-ic disaster
https://www.youtube.com/watch?v=eqIvzvB--0s

Sacred Cow Shipyards hosts a bunch of sub memes on this video while talking about dark humor.   

[WLJ]

You could say it was a Titan-ic disaster
https://www.youtube.com/watch?v=eqIvzvB--0s

Sacred Cow Shipyards hosts a bunch of sub memes on this video while talking about dark humor.   

Bonus points if you get the Babylon 5 one at 03:20 

Edit: 07:05 Gowron eyes 

I'm still watching

[MechAg94]

I vaguely remember of that episode to get the joke.  I rewatched the series, but it was a few years ago before COVID.

[MechAg94]

double post.

[K Frame]

they've started bringing up pieces of the sub...

https://www.msn.com/en-us/travel/news/imploded-titanic-submarine-seen-for-first-time-as-pieces-recovered-up-from-sea-floor/ar-AA1daiXG?ocid=entnewsntp&pc=U531&cvid=88d122cd506f4c3db445d88c94d721b4&ei=34

[Brad Johnson]

Saw a passing reference Facebook about builders screwing stuff into the hull (ie creating flaws in the CF matrix). I always take FB stories with a grain of salt, but looked up photos unrelated to the FB story and it seems to check out.

From what I'm seeing in the photo below, it does indeed appear they mounted monitors and other items directly to the pressure hull with what appear to be simple screws. Even if there's a mounting plate behind it, that's a discontinuity in the CF, essentially wrecking the structural integrity of the entire assembly.





Nothing says "Hey, I'm an idiot!" like haphazardly screwing things into the pressure hull of a submersible destined for use at 200+ atmospheres. 

Brad

[WLJ]

Just saw something somewhere that mentioned a liner inside the sub.

[Brad Johnson]

Just saw something somewhere that mentioned a liner inside the sub.

Would almost have to be. I just noticed there seems to be illumination coming from multiple locations under the ceiling surface. Unless they embedded some kind of light strip or fixture in the pressure hull itself, a liner would have to be used.

Brad

[WLJ]

Can't even remember what I was looking at when I saw that. Was more than likely scanning one of the million news pages I look at in the course of a day.

Edit: Bet I know what it was,. an article headline talking about the Titanic ocean LINER

[K Frame]

You know, the more I read about this sub, the less sorry I feel for the guy. It truly seemed like he was bound and determined to go out of his way to screw up.

Friend of mine sent me a clip of him doing an interview with a reporter, and he says something to the effect of "At some point, safety is a massive waste."

That's just... wow.

[cordex]

"At some point, safety is a massive waste."

If his point is that there comes a point of diminishing returns when it comes to safety he's absolutely correct.  Obviously he didn't have a solid enough grasp on where that point was, but none of us believe otherwise.

[WLJ]

Like I said earlier, if there's any justice in this it's the fact he went down with the sub. Sucks though he took 4 others with him.

[MillCreek]

The CEO would have pretty much spent a major chunk of his life in giving depositions and testimony. He was spared that.

[MechAg94]

If his point is that there comes a point of diminishing returns when it comes to safety he's absolutely correct.  Obviously he didn't have a solid enough grasp on where that point was, but none of us believe otherwise.

I was thinking about that first part also.  I agree there comes a point where safety is used as an obstruction rather than an improvement tool.  However, when we are talking about a self contained composite tube going down to 12,500 feet, that point of taking safety too far is way way out there on the horizon. 

That is why I was asking about manual backups for that controller the other day.  Even if the backups are not manual, there need to be backups, and they need to be independent in some way to try and eliminate single points of failure.  You normally apply that only to critical systems, but in this case, most everything is critical.  And that carries forward to construction as well since we don't know if they are screwing monitor stands into the hull.  It also carries over into inspections and mechanical integrity testing of the hull between dives. 

[dogmush]

I know that these things are expensive, but as far as I know this is the first CF cylindrical submersible ever built.

Modeling is nice and all, but I'd probably want to test a prototype to destruction before I put a bunch of people in it.  Talking about repeated pressure cycles, this was the first sub, and this trip was the first time one had hit this pressure cycle.

At least raise and lower the prototype 10 or 15 times unmanned, and if it makes it cut it apart to see what happened to the hull.  Then you'd have a feel for cycle lifespan.

As far as I can tell their testing program was like that line from Yellowstone: "Best we came up with, sir, is like *expletive deleted*ck it, ya know?"

[WLJ]

Lets not lose sight of the fact that this, despite what the brochure may have said, was basically a tourist excursion, yes a high risk one, and safety wise should have been treated as such.

[BobR]

Lets not lose sight of the fact that this, despite what the brochure may have said, was basically a tourist excursion, yes a high risk one, and safety wise should have been treated as such.

Much like the space tourist industry. I fully expect a catastrophic end to one of those.

bob

[cordex]

Much like the space tourist industry. I fully expect a catastrophic end to one of those.

Yep, and immediately afterward we'll have tons of posts saying "what they should have done was ..."

[HankB]

They're bringing up some fragments of the sub using ROVs.

https://www.yahoo.com/news/imploded-titanic-submarine-seen-first-144824288.html

With chunks of the sub in hand, maybe they'll figure out why it failed . . . or maybe they won't. But it wouldn't surprise me if analysis showed that the failure originated at the joint between the carbon fiber body and one of the titanium end caps.

[Ben]

Interesting. The Yahoo article seems to allude that the nose hatch was brought up relatively intact. I wonder if the overall shape of the sub caused hull implosion to "explode" the hatch outward?

[K Frame]

If his point is that there comes a point of diminishing returns when it comes to safety he's absolutely correct.  Obviously he didn't have a solid enough grasp on where that point was, but none of us believe otherwise.

Well, we'll never quite know what he was thinking because the last thing through his mind was apparently a high velocity chunk of the hull.

That said, everything I've seen about this device's construction gives a very strong impression that he had absolutely NO regard for safety at all.

He really reminds me of a richer version of that jackass who built his own steam powered rocket to "prove" that the earth was flat.

He's quite dead, as well.

[BobR]

Well, we'll never quite know what he was thinking because the last thing through his mind was apparently a high velocity chunk of the hull.

That said, everything I've seen about this device's construction gives a very strong impression that he had absolutely NO regard for safety at all.

He really reminds me of a richer version of that jackass who built his own steam powered rocket to "prove" that the earth was flat.

He's quite dead, as well.

His rocket "worked" the first time also. It was a later attempt that got him.

bob

[230RN]

Sidebar. The outfit that recovered the debris.  Interesting that they could get down there and fiddle around.  Ummanned, of course, but apparently capable of quite delicate operations.  And communicate with the surface... acoustically, I presume.

https://duckduckgo.com/?q=Pelagic+Research+Services&t=brave&ia=web

(Search engine results.  Contains several packages of info.)_

[MillCreek]

^^^I think it is cute that the ROV retrieving the debris has a couple of milk crates to drop things into.  No need for fancy stainless or titanium baskets when we can get some milk crates from the back of the Safeway!  For years I used a similar milk crate on the back of my Suzuki WeeStrom.  I used zip ties to attach it to the rack and it gave me years of loyal service.