Also in the News - Part 2

[Jon the Hat]

1 hour ago, The Doctor said:

Doing that and sending it down anyway... Its not nice to say but if it hadn't gone down with a full compliment of passengers you'd be wondering about insurance fraud with this level of intentional negligence 

Worrying article, but I am somewhat puzzled as to why I read all that to find right at the end the line: Spencer Composites says that the Titan was not using its carbon fiber hull on Sunday’s dive.

[FoxesDeb]

http://BBC News - Migrant crisis: Tunisian fisherman finds dead bodies in his net https://www.bbc.co.uk/news/world-africa-65952520

 

Grim reading, the whole article.

[yorkie1999]

3 hours ago, ClaphamFox said:

The BBC live feed is reporting on ‘banging sounds’ being picked up in the area the sub disappeared…

 

https://www.bbc.co.uk/news/live/world-us-canada-65953941

Bet it’s the sub bumping into the titanic, they’ve only got a plastic PlayStation controller and I doubt you’d hear that from 12000 feet away. 

[ClaphamFox]

Just now, yorkie1999 said:

Bet it’s the sub bumping into the titanic, they’ve only got a plastic PlayStation controller and I doubt you’d hear that from 12000 feet away. 

It's been reported that the noises have been heard at regular 30-mminute intervals, which would suggest those on board are alive and trying to communicate. 

[stripeyfox]

Even if they locate the sub at the bottom of the ocean, is there any actual way of rescuing the passengers (assuming they are still alive)?

 

 

Edited 21 June 2023 by stripeyfox

[yorkie1999]

4 minutes ago, stripeyfox said:

Even if they locate the sub at the bottom of the ocean, is there any actual way of rescuing the passengers (assuming they are still alive)?

 

 

The only way is to lift it up which, apparently, is not that difficult to do. 

[OwnGoal]

If they save them I just know the film will be out next year. As the potential to be harder viewing than both the Thai Cave rescue film and that Netflix movie where the two girls climb that massive phone mast thingy. The anxiety of watching them pair was bad. This will be next level. 

[leicsmac]

31 minutes ago, yorkie1999 said:

The only way is to lift it up which, apparently, is not that difficult to do. 

The problem then becomes pressurisation. No point in bringing the thing up if everyone then turns inside out upon opening it.

[stripeyfox]

 

first  they've got to locate the sub - which is pretty difficult I imagine. You would think it would have some kind of "ping" which could be picked up by a sonar device.

 

Then they've got to send another submersible (ROV? - or are there other  "manned" machines available to go to that depth) down. If it can be established that the occupants are still alive then they have got to find a way of "raising" it slowly (I think I read it is around 8 hours to raise "safely")

 

and all with a dwindling amount of O2. I'd say the chances of a good outcome here are very low

 

 

 

[Flamey]

24 minutes ago, leicsmac said:

The problem then becomes pressurisation. No point in bringing the thing up if everyone then turns inside out upon opening it.

Agreed, but maybe lift it high enough to a rescue sub level which would have depressurisation equipment?

[grobyfox1990]

58 minutes ago, OwnGoal said:

If they save them I just know the film will be out next year. As the potential to be harder viewing than both the Thai Cave rescue film and that Netflix movie where the two girls climb that massive phone mast thingy. The anxiety of watching them pair was bad. This will be next level. 

Successful multi jurisdictional business men on board. They’ll be negotiating their book, film and appearance fees as we speak. Knowing brokers and lawyers they will have found a communication feed down there and be presenting draft agreements for sign off 

[ClaphamFox]

7 minutes ago, Flamey said:

Agreed, but maybe lift it high enough to a rescue sub level which would have depressurisation equipment?

Isn't air in subs kept at a normal pressure like an aeroplane, and therefore no decompression is needed? 

[The Doctor]

1 hour ago, stripeyfox said:

Even if they locate the sub at the bottom of the ocean, is there any actual way of rescuing the passengers (assuming they are still alive)?

 

 

Would be very difficult, very few subs can go to that depth. Could potentially send a ROV to attach to it and haul it up if it can't move under its own power but idk if we've actually got the tech to haul things up from that deep, you're looking at over 1000 atmospheres of pressure pushing back down on it.

[The Doctor]

17 minutes ago, stripeyfox said:

 

first  they've got to locate the sub - which is pretty difficult I imagine. You would think it would have some kind of "ping" which could be picked up by a sonar device.

 

Then they've got to send another submersible (ROV? - or are there other  "manned" machines available to go to that depth) down. If it can be established that the occupants are still alive then they have got to find a way of "raising" it slowly (I think I read it is around 8 hours to raise "safely")

 

and all with a dwindling amount of O2. I'd say the chances of a good outcome here are very low

 

 

 

There kind of are, James Camerons one that went down the challenger deep a few years back, but getting them on site is the issue with the time restrictions.

[Flamey]

9 minutes ago, ClaphamFox said:

Isn't air in subs kept at a normal pressure like an aeroplane, and therefore no decompression is needed? 

No idea...think I will tap out at this point! 🤣

[SpacedX]

3 minutes ago, The Doctor said:

 you're looking at over 1000 atmospheres of pressure pushing back down on it.

About 400 I think. 

[The Doctor]

Just now, Line-X said:

About 400 I think. 

You're right, I'm thinking of the Mariana Trench and the subs that would be able to get down there 

[leicsmac]

Every 10m depth is one atmosphere of pressure, as a rule.

 

The sub may not be pressurised exactly to that depth, but the pressure differential will still be huge and so sorting that will also take time, care and resources.

[yorkie1999]

1 hour ago, leicsmac said:

The problem then becomes pressurisation. No point in bringing the thing up if everyone then turns inside out upon opening it.

Is that a problem with a submersible? 

[leicsmac]

42 minutes ago, yorkie1999 said:

Is that a problem with a submersible? 

Well, my knowledge of submarine engineering isn't encyclopaedic, but bear with me...

 

Manned submersibles are hardened against increased pressure differentials (the difference between the air pressure inside the craft and the water outside), but when you get to a deep enough depth of water, pretty much any craft that we can design that has air inside is going to fold up like Leicester in the second half of last season - the difference in pressure is just too big for whatever materials and design we make to withstand. That's why submersibles have a "crush depth".

 

So, to actually get down to places where the pressure is that high without becoming a small tin can, these submarines will have to pressurise the air inside to more closely match the pressure outside. This is pretty standard for diving work.

 

This craft will be no exception, and will have been pressurised to a certain amount/depth inside - low enough to keep the passengers and crew comfortable, but high enough to keep the pressure differential between inside and outside from flattening it.

 

As a result, if/ when these guys are found, when the door is opened it must be to an air pressure similar to what they have now. If it's not, then the best to expect is bad decompression sickness. At worst...well, turning inside out isn't even the half of it. )Look up the "Byford Dolphin" for more on what happens when the human body is exposed to a large pressure differential suddenly.)

 

So yes, they can't just raise it up and pop the hatch, they're going to also need special submarines and decompression chamber facilities close by if anyone is to survive.

[leicsmac]

1 hour ago, ClaphamFox said:

Isn't air in subs kept at a normal pressure like an aeroplane, and therefore no decompression is needed? 

A comment on this: airplanes aren't exactly kept at "normal pressure" because at 37000 feet, the pressure differential would cause strain on the aircraft materials. Usually, they're kept at a pressure equivalent to about 4000-8000 feet altitude, enough for people to still mostly feel OK (but don't go diving just before you fly!), but also enough so that not so much strain is put on the airframe, especially again and again.

[Trumpet]

7 minutes ago, leicsmac said:

A comment on this: airplanes aren't exactly kept at "normal pressure" because at 37000 feet, the pressure differential would cause strain on the aircraft materials. Usually, they're kept at a pressure equivalent to about 4000-8000 feet altitude, enough for people to still mostly feel OK (but don't go diving just before you fly!), but also enough so that not so much strain is put on the airframe, especially again and again.

Although I’m a bit of an aviation nerd, pressurisation isn’t my strong point - the changing of pressure during descent is why ears tend to pop, I think?

[leicsmac]

2 minutes ago, Trumpet said:

Although I’m a bit of an aviation nerd, pressurisation isn’t my strong point - the changing of pressure during descent is why ears tend to pop, I think?

That's right, as you go through final descent (and initial ascent), the pressure inside the aircraft will slowly change, and you feel it in your ears.

Edited 21 June 2023 by leicsmac

[The Doctor]

7 minutes ago, leicsmac said:

A comment on this: airplanes aren't exactly kept at "normal pressure" because at 37000 feet, the pressure differential would cause strain on the aircraft materials. Usually, they're kept at a pressure equivalent to about 4000-8000 feet altitude, enough for people to still mostly feel OK (but don't go diving just before you fly!), but also enough so that not so much strain is put on the airframe, especially again and again.

 

12 minutes ago, leicsmac said:

So yes, they can't just raise it up and pop the hatch, they're going to also need special submarines and decompression chamber facilities close by if anyone is to survive.

https://www.bbc.co.uk/news/world-us-canada-65969476

 

Fortunately that is on hand *if* it's found: "Two Canadian Coast Guard ships and a Royal Canadian Navy ship equipped with a six-person mobile hyperbaric recompression chamber are also en route."

 

Less than 24 hours of oxygen left for 5 people, there's only one way to make the maths math for longer survival, and it involves a long pork dinner

[leicsmac]

Just now, The Doctor said:

 

https://www.bbc.co.uk/news/world-us-canada-65969476

 

Fortunately that is on hand *if* it's found: "Two Canadian Coast Guard ships and a Royal Canadian Navy ship equipped with a six-person mobile hyperbaric recompression chamber are also en route."

 

Less than 24 hours of oxygen left for 5 people, there's only one way to make the maths math for longer survival, and it involves a long pork dinner

I can't laugh react to that because of the second half of the post, damn it.

 

Glad they have the gear in place, but they still need to find them and do everything in a very short time frame.