Titanic submersible

Indeed. I was once asked to look at the electrical supply for a pump being fittted to an aircraft. It was to pump fuel from a belly tank to a high wing tank. The pump was in the wing. I was not popular when I pointed out that at cruise altitude there was not enough air pressure for it to work. The highly qualified system designer did not realise that it the pump only created a vacuum and air pressure pushed the fuel up the pipe. He didn't belive me but I attended a meeting with the pump supllier who promply said their product would not work when he was shown the concept drawing. They ended up with a pump in the belly tank. I also pointed out that on a hot day the fuel would "boil" if they tried to lift it by vacuum. They then realised that while I was employed s a Avionics designer I was also experiened and qualified on fuel systems.....

Robert.

Edited By Robert Atkinson 2 on 24/06/2023 19:13:12

Hi Robert, taking about vacuum pumps, I had to give a new chap a water pump job, you know the sort of person, been everywhere and what he didn't know, wasn't worth learning about. Anyway he had to set up a portable land based pump, which had a vacuum pump to prime the water pump, after about an hour setting out all the pipework etc., he came back to me to say the pump wouldn't pump the water, and asked if I could have a look. Well the pit he had to pump out was about 50 Ft. below a bank, when I went to look, I saw the pump on the bank and 50 Ft. of suction pipe going down to the pit. I simply told him there and then that he would have to alter his pipes and move the pump down to the lower space next to the pit, as the vacuum wasn't capable of lifting the priming water to the height of the bank, he doubted me, but I told him he had no choice, he wasn't very happy to have to move the pump, but soon realised I was right when it pumped within a minute or so after starting it, once he got it into the correct place.

Regards Nick.

Edited By Nicholas Farr on 24/06/2023 21:03:45

Where I work, we employ a physicist who specialises in fluid dynamics, he has a phd in the subject...I will ask him on Monday what he thinks happened during the failure and report back.

All the best

Derek

Well-played, Derek

MichaelG.

What I don't understand is why they were running at atmospheric pressures. IIRC you can handle 2-3bar abs without decomp, and you have two hours for that if needed.

Fulmen 30 odd psi inside would not have made any difference when you have got a few thousand psi on the outside. Please correct me if I am wrong.

With 6000psi acting on every square inch of your body , you will be turned to dust 150 milliseconds before your brain could register it happening . At least they didnt suffer.

Fulmen -

Submarines and submersibles normally work at atmospheric pressure inside.

The object of the design is to make the pressure-hull withstand the external pressure, which increases at the rate of 1 Atmosphere for every 10m depth, with a factor of safety - and repeatably.

It was only civil-engineering caissons that were pressurised internally, and it was using these that caused the first cases of "the bends". ( I don't know if they are still used, though obviously with much more stringent practices and precautions).

@Baz: You're right, I have been in the sun too long today. I started thinking in ratios, not difference for some reason.

The high pressure systems were so divers could work at depth, entering and leaving the capsule

Hazardous stuff, even nowadays, they also had to breathe some weird mixtures of gasses

THIS BBC article contains the following, from a retired submarine officer:

....................................................................

Which is probably the source of the "turned to dust" that seems to be mentioned everywhere on the media. Sounds like something crews are all taught at submarine school.

But is a submarine the same situation? Depth is nowhere near the Titan's, so pressure would be far less. Submarine is much larger, giving more time and distance for the water to accelerate before meeting the oncoming water, so possibly higher velocity.

And the auto-ignition of hydrocarbons under compression in the air in a sub is probably not relevant to the Titan. Submarine is full of all sorts of oils and solvents and possibly diesel fuel for standby generators etc. Certainly a conventional sub is awash in diesel fumes from the main engines and their fuel supply, some of which inevitably ends up down in the bilge before being run through a separator and stored in a tank to be environmentally consciously disposed of in port. My ex-submariner co-workers at the shipyard building Collins subs told me the stink of diesel fuel was a pervasive fact of life in a sub, rivalled only by human flatulence, which was elevated to an artform as the main source of entertainment. They were all crazy.

Edited By Hopper on 25/06/2023 00:24:50

Edited By Hopper on 25/06/2023 00:26:46

Looking forward to hearing what he says. Well done.

With the exception of the last line of the last quote from the US submariner, which was included to explain the pervasiveness in the media of statements about turning to dust, the discussion here is purely the engineering aspect of what happened to the vessel itself from a technical viewpoint. And nobody is claiming to know everything. Quite the opposite in fact. Your personal insults are quite out of line.

This stuff is going to be all over the media for the next six months and more as the official inquiry and various legal actions etc proceed. This obscure thread makes not one jot of difference in the overall picture.

Edited By Hopper on 25/06/2023 00:54:27

I suppose we and the families of those who died ought to take solace from the fact that those on Titan died instantly.

I don’t believe that there was any forewarning or that any prior attempt was made to resurface or ditch ballast.

It was a catastrophic failure that led to instant death, so quick, that without any conscious of what had happened.

I don’t think that anything debated on here would cause any of the families of those who died any concern. They would want to know that their loved ones didn’t suffer.

I think you'll find that at a given depth the pressure in a liquid is the same in all directions, but it gets higher as you go deeper.

Give it a rest guys. Let the dead lie

I don't mind exiting this thread but they were grave tourists paying 200k a pop to ogle at a disaster site with hundreds of victims

And for what? A bucket list tick?

Edited By Ady1 on 25/06/2023 01:34:00

Yes that is the point. We were led by the media to believe for several days that those people were alive and desperately banging on the hull for rescue until the air ran out. An instantaneous catastrophic implosion is in fact good news under the circumstances.

Edited By Hopper on 25/06/2023 02:06:52

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… and I think Nick makes a very good point, Duncan

Difficult to visualise, but all about vectors

A gas exerts the same pressure in all directions, because the pressure is generated by molecular activity. But the hydrostatic pressure is dominated [umpteen orders of magnitude] by Gravity, and is therefore directional.

As I opined previously … the column of water will descend to occupy the vacant space before it has time to do any significant shape-changing.

No … I am not an expert, I am just here to improve my own infinitesimal comprehension of things by discussion [the most useful part of which involves ‘listening’], so I was grateful that Nick, with his hands-on experience, seemed to endorse my hypothesis.

Understanding Nature is a work-in-progress, but barely started !

MichaelG.

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Amen to that, Hopper

Surely there is no “better way to go”

MichaelG.