Titan Terminated at Titanic

[lpm]

If it has bobbed up to the surface there's a chance it could be spotted in the remaining few hours before they are out of oxygen. 20% chance the surface search would find it in a day?

If it's submerged there's zero chance of finding it, not that finding it would help in the slightest.

[Fishnut]

I'd be highly surprised if it's made it back to the surface. Given its depth when it was lost and reports that there were structural issues with the sub a few weeks ago it seems most likely it's lost structural integrity and its occupants quickly did the same. A quick way to go, at least, and probably the best outcome given the only other likely one is them suffocating to death.

If it does get to the surface, trying to spot it won't be easy. I know it's fairly big for a submersible but the ocean is bigger, they have no idea where it will have surfaced and it's white/grey which doesn't exactly stand out against the water. Plus it isn't clear how high in the water it sits - it could easily be bobbing a few feet below the surface and impossible to see from above.

[lpm]

I would have thought a dump ballast button would be somewhere. So plenty of scenarios where they lost comms or propulsion, but could still emergency surface?

[nekomatic]

I'm no fan of making light of people (probably) losing their lives but I think a bit of incredulity that anyone got into this thing is fair comment. And it literally is true that men tend to engage in riskier behaviour than women resulting in some of them dying sooner.

The basic shape of submarines is the same for all of them, the simplest vessels for deep sea are just spheres, they can get made bigger by putting a cylinder between hemispheres. This is similar for vessels designed to keep pressure in as well as out, which is why it resembles a hot water cylinder.

One Twitter comment observed that the craft is apparently made of carbon fibre composite which seems an odd choice for withstanding rather than containing pressure.

And the obvious comment to make is on the contrast between this and another recent maritime disaster.

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or if you don't mind a tiny bit of levity

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[TopBadger]

Image of same or similar vehical.
Spoilered cos nsfw
I kid you not
Spoiler:

bzzzzz.png

Not sure what's NSFW about that. Seems that military subs typically don't go much past 900m in depth... so commercial subs are 'it' when it comes to deep sea diving.

This isn't true. Alvin is US government owned and operated - Alvin is a US Navy vessel operated by Woods Hole Oceanagraphic Institute. The US Navy has two 1500m capable submarine rescue vehicles, and the Japanese government owns and operates Shinkai 6500. The Chinese government has a couple of deep ocean capable submersibles and bathyscapes.

Eh? I say military subs typically don't go much beyond 900m (and therefore military rescue craft don't need to go too much further beyond it either) and you quote 1500m... 1500m isn't much further, and certainly isn't enough to reach Titanic (3800m below).

The Shinkai 6500 isn't military, and being Japanese is likely on the opposite side of the world anyway.

You seem to be splitting hairs here chap, my general thrust is that a high tech military rescue isn't likely to be coming.

[IvanV]

If it has bobbed up to the surface there's a chance it could be spotted in the remaining few hours before they are out of oxygen. 20% chance the surface search would find it in a day?

If it's submerged there's zero chance of finding it, not that finding it would help in the slightest.

I presume the main detection method, whether the lost sub is surface or submerged, is sonar. Sonar is apparently used to locate drowned bodies floating on the sea, so it ought to be a bit easier to find a metal object "the size of a truck". Though it becomes difficult at the point it is lying on the sea bottom, 4km down, and so hard to distinguish from the bottom of the sea. It was hard to locate the Titanic wreck itself. But you'd think a submersible still off the bottom would give a clear sonar detection reflection to objects trying to seek it from the surface, if they were using suitable detection methods.

Anyone have any idea what the detectability using sonar that might be available to them is?

I'm a bit confused why they need to search an extensive area of sea. They were talking about an area the size of Connecticut, using the much more complex US measurement system. In UK measures, that's about 0.6 Wales. How can it have moved very far? Or if there are currents, those are surely capable of being taken into account?

Having read that this submersible is supposed to give off a sonar ping every 15 mins, if it is no longer doing that, then that would tend to suggest a disastrous situation. At least with a half sensible design. Given they lost it before for 5 hours, that does suggest it can stop giving its ping and still be intact - or else the ping isn't very useful. It does seem remarkable that they failed to give attention to a resilient location system, given the problems they had losing it before.

...

17 bolts/Apollo. Being at 4000m down in the sea presents a pressure difference between interior and exterior of a quite different magnitude from being in space. It's only a 1 atm pressure difference in space, but at 4000m it's a 400 atm pressure difference. So you need a a structural seal of much greater integrity than a space vehicle would require. I doubt you can have quick release entrances on a deep sea submersible.

[nekomatic]

It's only a 1 atm pressure difference in space, but at 4000m it's a 400 atm pressure difference. So you need a a structural seal of much greater integrity than a space vehicle would require. I doubt you can have quick release entrances on a deep sea submersible.

The differences are opposite in sign though. If the door to a sub were a plug seal from the outside then once submerged a bit one would think it wouldn’t really need any bolts at all.

[Grumble]

The Onion reports that the coastguard have sent another submarine full of billionaires on a rescue mission

https://www.theonion.com/coast-guard-se ... 1850556819

[dyqik]

Not sure what's NSFW about that. Seems that military subs typically don't go much past 900m in depth... so commercial subs are 'it' when it comes to deep sea diving.

This isn't true. Alvin is US government owned and operated - Alvin is a US Navy vessel operated by Woods Hole Oceanagraphic Institute. The US Navy has two 1500m capable submarine rescue vehicles, and the Japanese government owns and operates Shinkai 6500. The Chinese government has a couple of deep ocean capable submersibles and bathyscapes.

Eh? I say military subs typically don't go much beyond 900m (and therefore military rescue craft don't need to go too much further beyond it either) and you quote 1500m... 1500m isn't much further, and certainly isn't enough to reach Titanic (3800m below).

The Shinkai 6500 isn't military, and being Japanese is likely on the opposite side of the world anyway.

You seem to be splitting hairs here chap, my general thrust is that a high tech military rescue isn't likely to be coming.

I'm not splitting hairs, I'm pointing out that most deep sea submersibles are government owned and operated, not commercial, as you claimed. There's plenty of things that aren't commercial and aren't military.

Shinkai 6500 is not commercial, it's a government research vessel. Alvin (and its former sister ships) is US Navy owned, and NOAA operated.

[EACLucifer]

Lpm knows this. It's fake argument-from-incredulity. Likewise with the game controller thing, electrically actuated control surfaces or thrusters don't need yokes to move cables or hydraulics. After all, Airbus passenger jets are flown using a joystick, like the ones computer nerds use.

Men are idiots though

I could point to earlier threads about generalising and prejudice, or I could start explaining how pushing generalisations about half the population also legitimises generalising about the other half, but frankly none of it's going to sink in so I'm just going to point out you're being a dickhead and tell you to f.ck off.

[Millennie Al]

As referenced above, from Twitter:

Joanne Harris
@Joannechocolat

5 people, paying 250k to travel in an unsafe vessel to a dangerous place.
500 people, in an unsafe vessel, trying desperately to get to a safe place.
Why do some people feel such a connection with the first group, but not the second?

I see evidence of the opposite here. Considerable sympathy for the 500, and somewhat negative comments about the 5. And even looking at the Twiter thread, I see https://twitter.com/AJGavaghan/status/1 ... 1848052738:

AGavaghan
@AJGavaghan

And why is the wealth of those on board being highlighted, as if their lives are somehow worth more than the poor?

You can ask the opposite question: why is the wealth of those on board being highlighted as if that is somehow worth more than their lives.

[Millennie Al]

I hope that OceanGate will be paying for all this help.

That's not how rescues work. People rescued may well feel such gratitude that they start fundraising for the organisation that rescued them (since they are rarely personally wealthy to be able to pay as much as they can raise), but rescues are usually free, regardless of how much stupidity went into setting up the need for rescue or the cost of the rescue. Once you start expecting people to pay for their rescue, you'll have howls of outrage at illegai immigrants being excused payment due to being too poor.

[noggins]

I wonder if Salvage applies to civilian submarines?

[IvanV]

I hope that OceanGate will be paying for all this help.

That's not how rescues work. People rescued may well feel such gratitude that they start fundraising for the organisation that rescued them (since they are rarely personally wealthy to be able to pay as much as they can raise), but rescues are usually free, regardless of how much stupidity went into setting up the need for rescue or the cost of the rescue. Once you start expecting people to pay for their rescue, you'll have howls of outrage at illegai immigrants being excused payment due to being too poor.

If you want to go on an expedition in Greenland, then the local authorities make you buy insurance or a bond to cover rescue costs. It's not cheap. If you succeed in setting off without doing that, and get into difficulty, then you will be liable for the cost of the rescue. The Greenland wilderness is not a route favoured by refugees, so those issues do not arise.

Greenland is not the only place you have to pre-arrange your rescue, including payment. It can be a condition of obtaining a mountaineering licences in certain ranges of mountains, for example. Whilst those are formal arrangements, there are many other places in the world where, without any such formal arrangements existing, getting people to turn out to come and try and rescue you may be difficult if you have not made some kind of advance arrangement, including funding for it. And attempting to travel without permission in places where you should have permission, according to local laws, whether as refugee, researcher or sightseer, well their response might be a lot less friendly than trying to rescue you. (See for example the 46-day crossing of the Chang Tang by bicycle by Saulnier and Corax - they nearly died and shouldn't have been there, so the Chinese authorities were not very friendly when they turned up in a bad way.)

Countries and passing ships do have a duty under the 1982 United Nations Convention on the Law of the Sea to help those in distress at sea. When the incident is far out at sea, as in this case, and when rescue is a lot more complex than just sending a boat or helicopter to pick you up, then it is rather unclear how far that duty extends. The Canadians here turned up with specialist equipment, even though this is over 1000km off their shore, well outside their territorial waters by any definition. Many other countries would not do that, and most would not even have the ability to do so.

It strikes me as at least possible that OceanGate had arrangements with the Canadian authorities in event of problems, especially after their recent earlier difficulties. Though they have been so lax in other ways, maybe they didn't, and were just hoping they'd be nice.

[bjn]

What Ivan said. I have been on a few adventurous trips in my life, including mountaineering on the Greenland ice sheet. A major costs for that trip was rescue insurance.

[dyqik]

Countries and passing ships do have a duty under the 1982 United Nations Convention on the Law of the Sea to help those in distress at sea. When the incident is far out at sea, as in this case, and when rescue is a lot more complex than just sending a boat or helicopter to pick you up, then it is rather unclear how far that duty extends. The Canadians here turned up with specialist equipment, even though this is over 1000km off their shore, well outside their territorial waters by any definition. Many other countries would not do that, and most would not even have the ability to do so.

It strikes me as at least possible that OceanGate had arrangements with the Canadian authorities in event of problems, especially after their recent earlier difficulties. Though they have been so lax in other ways, maybe they didn't, and were just hoping they'd be nice.

It's also possible that this rescue assistance helps them meet their internal training quotas, which has budgeted funding already in place.

Plus rescuing a few billionaires is probably good for next year's budget request, and to justify why you have this kind of equipment.

[Imrael]

This might be out of date, but Canada used at one point to do a lot of (Soviet) submarine location and detection in the North Atlantic. They may well have both equipment for the task and skills that would benefit from training/practice.

In other words they may have both humanitarian and practical reasons for attempting to help.

[lpm]

None of that submarine stuff is at 4 km down!

There's no point in practicing for that depth. They'd be better off doing a pretend scenario at 300 metres.

To maximise odds, any ship that could lower a submersible should track back and forth across the surface, not actually lower the submersible.

[Imrael]

None of that submarine stuff is at 4 km down!

There's no point in practicing for that depth. They'd be better off doing a pretend scenario at 300 metres.

To maximise odds, any ship that could lower a submersible should track back and forth across the surface, not actually lower the submersible.

Not exactly disagreeing because I dont know, but theres been a bit of focus on cables lying at considerable depths. The French have program to be able to operate to 6Km depth (Remote of course) and I think the US also have some stuff. No idea whats operational or whether canada has any. Its obviously rare. Even more than space, the deep oceans dont seem to be a use case for actual human presence.

I did hear somewhere that the surfacing mechanism would actually have left this fairly small craft just under the surface, which would have made more standard ASW stuff relevant. No idea if thats true though. (It does make your point about surface tracking even stronger if it is true).

This has probably been a body recovery operation from day one, and I'd think a certainty now. I kind of hope it was a quick death - its not in me to cheer torturing strangers to death over several days even if they are rich idiots.

[lpm]

There is a ship on site that can lower a 4,000m cable. Not sure what the angle ends up being with the currents but it's not a lot of slack if the sub is at 3,800.

There is also an ROV that can operate at 4,000m.

I'm presuming once the submersible is located it would take a day or two to prep the ROV, send it down, tie the string on, winch it to the surface and open it up. The actual deadline was passed long ago.

[IvanV]

It would have been a good idea to have a cable attached to the thing in the first place. Clearly cable snags are a potential issue, but it would give additional recovery options most of the time.

5000m of 25mm steel cable, if that would do, weighs very roughly 25 tonnes. So clearly the ship would need sufficient size and some serious machinery, and doubtless this would make it all a lot more expensive.

[jaap]

It would have been a good idea to have a cable attached to the thing in the first place. Clearly cable snags are a potential issue, but it would give additional recovery options most of the time.

5000m of 25mm steel cable, if that would do, weighs very roughly 25 tonnes. So clearly the ship would need sufficient size and some serious machinery, and doubtless this would make it all a lot more expensive.

I just don't understand why there wasn't some kind of locator beacon on it. On the outside, with its own battery to make it independent of the electrical systems.

[Pishwish]

https://twitter.com/cfishman/status/167 ... 03974?s=20 Thread, including 2 articles, on the rescue effort.

[noggins]

It would have been a good idea to have a cable attached to the thing in the first place. Clearly cable snags are a potential issue, but it would give additional recovery options most of the time.

5000m of 25mm steel cable, if that would do, weighs very roughly 25 tonnes. So clearly the ship would need sufficient size and some serious machinery, and doubtless this would make it all a lot more expensive.

I just don't understand why there wasn't some kind of locator beacon on it. On the outside, with its own battery to make it independent of the electrical systems.

Every commercial ship in the world has a locator beacon as part of the voyage data recorder.

The beacons work down to 20,000 feet and cost about 600 quid.

[Grumble]

Interesting difference between this submersible, which as someone pointed out up thread has not been subject to regulation, and indeed the owner has stated that regulation slows down innovation, and a submersible which goes to the bottom of the Marianas Trench and has fully involved the Norwegian regulator since day 1. I think I know which attitude I prefer.