Titanic tourist submersible goes missing with search under way

hamburgham

I've learnt so much from this thread, so many of you are so knowledgeable.

15 mins in an MRI was bad enough for me, nothing would get me into that, on land never mind under water.

AndyBoBandy

Heres some interesting reading on the deepest successful rescue of submariners ever, which happened off the coast of Cork;

They were at a depth of 480m and it was an extremely difficult rescue.

https://www.irishexaminer.com/news/munster/arid-41167276.html

https://en.wikipedia.org/wiki/Rescue_of_Roger_Mallinson_and_Roger_Chapman

MacDanger

A couple of questions for those of you who have some knowledge in this field - let's say that these people were still alive and trying to signal (3 mins every 30mins):

• what would be the best thing to use to signal from an acoustics point of view? Shouting? Banging metal on metal (I'm guessing that banging on the vessel wall would be dangerous?)? Or does the type of sound generated matter much?
• and secondly what are the chances that the sound would be able to escape a vessel which is rated for these kind of depths? I'd have thought the vessel would provide a level of "insulation" that'd hamper the sounds getting out

Mefistofelino

https://www.boards.ie/discussion/comment/120748394#Comment_120748394

And remember that in the case of Mallinson and Chapman, they knew exactly where the sub went down, what had happened, were dealing with "only" 480m depth, had rapid access to the right rescue equipment and the occupants were both experienced submariners. And yet it still took several days and its believed that the two crew had only minutes of oxygen remaining when rescued.

chooseusername

One called Roger would have made communications interesting, but two?

RetroEncabulator

We don't really know enough about the construction of the vessel to comment at this stage, other than it's a mixture of titanium and carbon fibre components. It's hard to know if it would carry. You'd think they'd have some kind of external sonar beacon though, it would seem like a rather obvious device to have.

There are a lot of concerns being flag in discussions about the design, for example the exposed thrusters keep coming up as they could have been knocked off or damaged.

Communication to deep ocean vessels is also not straightforward because radio waves don't pass through that depth of salt water very easily. Even very low frequency signals used for normal subs might be challenging at those depths. Normally for ocean exploration vessels they use some kind of long thing signal tether to get data and images back and forth e.g. a reinforced plastic fibre could be used.

Submarines typically communicate with very low frequency radio, and for quick phone home scenarios will release a tethered antenna on a buoy to the surface. For something non military this wouldn't be an issue. Military subs obviously prefer to be silent and hard to track.

There's also no standardised hatch or tower, so it's not possible to attach anything to the vessel to facilitate a quick escape or even connecting up an air supply externally. To get them out you have to bring the whole vessel up, undo seals and open the door.

standardg60

https://www.boards.ie/discussion/comment/120748048#Comment_120748048

Given that there were no tests conducted between trips it would seem that this early warning system was just another short cut.

The idea of it made me laugh, what's the point of an early warning system when you're 3000m down. What are you going to do about it at that stage?

Actually, hopefully it didn't go off a minute or two before implosion, that would have been terrifying.

RetroEncabulator

The other risk on something like this is a fire btw - electrical systems, source of potentially high concentrations of oxygen etc..

Mefistofelino

https://www.boards.ie/discussion/comment/120748477#Comment_120748477

Loss of a thruster shouldn't have prevented the vessel from surfacing (other than it getting snagged in wreckage etc) - the thrusters are for manouvering but the actual descent / ascent would have been controlled by adjusting buoyancy.

Loss could also have been due to a leak - sealing of porthole, cables for power / control passing through the hull etc. - flooding the interior. Not every loss of containment scenario would lead to implosion.

https://www.boards.ie/discussion/comment/120748477#Comment_120748477

We know a decent bit - there are photos and videos of it being constructed. It was a spun carbon fiber tube in the center with a titanium hemisphere on each end.

Titanium is a common material for submarines/submersibles. Carbon fiber is not - they boasted they were innovating and doing things other companies didn't do. Carbon fiber is a very unforgiving material, it's has to be manufactured very carefully, it's difficult to inspect and it fails without warning. They had strain guages around the hull, to compare how the hull was reacting from one descent to the next. Personally I am skeptical that these would be effective, i'm also skeptical that the CEO would pay attention to them, he seems very risk-tolerant.

Everybody has seen submarine movies where the hull starts to groan, then one-by-one pipes are springing leaks and guys are running around with spanners. That would not happen with this sub and at this depth. If the hull failed it would instantly shatter, the crew would be crushed by the water before they knew what was happening.

RetroEncabulator

Yeah, if there was an implosion it would have cracked like an egg.

AndyBoBandy

https://www.boards.ie/discussion/comment/120748441#Comment_120748441

I'm no expert but generally metal against metal would make the greatest sound, but crucially some of that metal should at least be a part of the outer shell/skin of the vessel, which would allow the sound out into the ocean.. Remember that the faintest sound can be detected.. (The analogy goes that a modern day military sub in New York Harbour would be able to hear & track a fishing boat in Galway Bay).

This sub supposedly has titaniam end caps, which would be ideal to strike something metal against... but do they have anything metal on board they could use to strike it? typically in movies they use a steel wrench/spanner/hammer, and that would indeed provide the greatest sound... Maybe they have access to spent oxygen cylinders which if metal would be blunt enough to bang against an end cap..

The 2 titaniam end caps would probably be the strongest part of the whole vessel, so there shouldn't be much issue with banging it a hammer type implement...

LambshankRedemption

https://www.boards.ie/discussion/comment/120747250#Comment_120747250

Everything going to plan you would spend 10 hours in there for your trip. Imagine spending 4 and a half days?

AndyBoBandy

Here's a good scene from The Abyss where a mini sub implodes, though I doubt it would actually happen like this whereby you see cracks appear and a leak spring in.... I'd imagine that in reality, and at the depth the Titan was at, it would have been milliseconds with no forewarning, and once the initial weak point failed, everything else would have failed almost instantaneously

https://www.youtube.com/watch?v=FkhBPF4yfkI

LambshankRedemption

• and secondly what are the chances that the sound would be able to escape a vessel which is rated for these kind of depths? I'd have thought the vessel would provide a level of "insulation" that'd hamper the sounds getting out

In submarine warfare, if an enemy sub is detected, the order will go out to rig the boat for silent running. That means everything in the ship gets strapped down. Even the plates in the galley are strapped down so there is no rattle which might give out some sound and therefore their position. Water is a better conductor of sound than air is. That is why whalesong can be heard hundreds of miles away. However, it does mean, due to the expanse of the ocean pinpointing where it is coming from is extremely difficult.

Of interest, a German sea Captain is facing charges in Italy for illegally rescuing around 1000 migrants on her ship.

chooseusername

How many times has this sub been down to the Titanic?

Yellow_Fern

https://www.boards.ie/discussion/comment/120747184#Comment_120747184

You say that but I do that all the time. I love visiting old grave yards. I once visited Ukraine a decade ago and the graveyards were fascinating. I would often accompany a visit with a prayer to the dead there. Same with shipwrecks. People love diving on shipwrecks. There is valid concerns about the risk of theft but I dont see anything wrong with it if the theft element is controlled.

AndyBoBandy

https://www.boards.ie/discussion/comment/120748704#Comment_120748704

I think I saw the number 30 mentioned somewhere.. Although that might just be 30 dives, and not all to Titanic.. Either way, if it was 30 deep dives, thats a lot of cycles of extreme pressure on an untested and uncertified carbon fibre hull!

AndyBoBandy

Here's the L'Atalante, which is the big French ship that arrived on scene today and deployed their ROV 'Victor-6,000'

Whatever happens from here, it's a recovery mission now as the widely mentioned 96 hour window is now closed.

may they rest in peace

https://www.boards.ie/discussion/comment/120748704#Comment_120748704

https://metro.co.uk/2023/06/22/how-many-times-has-the-titan-gone-to-the-titanic-and-how-deep-is-the-wreck-18994926/

Not very often

Tazium

RIP

Yellow_Fern

https://www.boards.ie/discussion/comment/120747250#Comment_120747250

Deepsea Challenger is even more cramped and goes down far far deeper. But in fairness, looks incredibly more sophisticated.

magicbastarder

is the pointy end of the sub pressurised? i.e. does it form part of the pressure hull?

AndyBoBandy

https://www.boards.ie/discussion/comment/120748808#Comment_120748808

I don't think so, I believe under that fairing there's another spherical titaniam dome similar to the one at the front end, but without the window.

Hotblack Desiato

https://www.boards.ie/discussion/comment/120748294#Comment_120748294

There's always some gobshite (not you!) putting a "US / NATO / Waaaah!" angle onto everything, regardless of evidence or lack thereof.

In the 80s a radar was blown up by the INLA (I think) and they said it was used for NATO blah blah despite of course the country it was in not being in NATO

It was a civilian air traffic control radar 🙄

LambshankRedemption

https://www.boards.ie/discussion/comment/120748704#Comment_120748704

The number keeps changing, I have seen the number 30 quoted in several places, however, I have just noticed in one article that it refferred to the fact that PH Nargeolet himself has made 30 dives to the Titanic. The OceanGate website says the Titan has gone down 3 times but has done over 50 test dives.

LambshankRedemption

https://www.boards.ie/discussion/comment/120748805#Comment_120748805

Yeah but Deepsea Challenger has a crew of 1. Titan has a compliment of 5.

Mefistofelino

https://www.boards.ie/discussion/comment/120748847#Comment_120748847

I think it was more than a knee-jerk reaction - I believe the accident location didn't coincide with the route of any of the then current transatlantic cable installations.

Juran

How on earth is there not a GPS tracking / locating system on that sub to track it when its on the surface. If it was to come up from a normal dive and the currents pushed it off course coming up and the sea is really choppy, the mother ship might not find it easily.

Surely you'd expect a tracker so the mother ship can find it quickly once it surfaces. its so sickening to think the support ships & planes have been looking on the surface for days, totally depending on visual contact to see if they surfaced. As someone already posted, its like looking for a transit van in the area of half of Ireland. A transit that would be bopping with almost all of it under the surface. It would not be above the surface like a small boat.

I know the chances are so slim that they surfaced, but a locator position device would rule it out, and have allowed assets to focus on underwater search from the start.