GM Guy
rollin' along...
That would be a major snag hazzard when they are poking around wrecks. Its not calm waters down there, so you could drift to places unexpectedly or venture too close and end up snagging.
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Tourist submarine exploring Titanic wreckage disappears in Atlantic Ocean
- Thread starter Landslide
- Start date
aczlan
Good Morning!
As I understand it, there is a loophole in Canadian law that let them load it as a "deck cargo" and not be inspected or regulated at all.It’s a flawed design, considering no other deep sea submersible vessels, that I can find at this time, resembles Titan’s non-sphere pressure vessel.
Crazy on how they thought they can get away with untested and unproven carbon fiber cylinder for the pressure vessel, let alone carrying fare-paying passengers in it.
Plus the hassle and expense of dealing with that much line, probably would greatly limit what they could use for ships and limit them to ones that cost more money
Aaron Z
plym49.2
Sasquatch49.2
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When the asteroid hits and a rag-tag group of survivors need to rebuild civilization, I hope it's all the IBB members. Excepting any that were a Fed, a ne'er-do-well, or a communist from the EU.At bottom at the Titanic wreck you're at a pressure of 5340psi. If you had 6000psi HP bottles to fill emergency lift bags, you only have 660 usable psi before the bottle was empty. It would take a lot HP bottles to work, but it would be technically possible.
The weight of all those bottles creates it's own set of issues to be delt with.
A good friend of mine's dad was part of the Trieste dives. Very cool guy and some interesting stories about it.
*When the plexiglass view port started to fail on the shallower dives, they went to lexan. Which was one of the earliest uses of the material.
*The sphere was measured after the last dive to the bottom. It was actually smaller by a small amount.
*They determined where to launch the sub by tossing explosives over the side of the mother ship and timed the return of the sound.
Mr. Rechnitzer ( friend dad) was supposed to go on the dive to the bottom. But Paccard wanted his son to have the glory so my buddies dad got bumped. He said Paccard was an asshole, hated him for years. Buddies dad did make the dive down past 20k feet.
11/16/59
Left to Right: Lieutenant Larry Shumaker, Assistant Officer in Charge; Lieutenant Donald Walsh, Officer in Charge; Dr. Andreas B. Rechnitzer, Scientist in Charge; Jacques Piccard, Co-Designer and Technical Advisor of Bathyscaphe Trieste.
Bathyscaph Trieste, 1960. Lieutenant Don Walsh, right, and Dr. A.B. Rechnitzer, possibly during testing by the Naval Electronics Laboratory in San Diego, California.
I can actually remember seeing the Trieste in Point Loma. My dad also worked at the Naval electronics Labatory.
sdmuleman
Red Skull Member
It's hard to wrap your head around the pressure at that depth. Gases behave differently under that kind of pressure. Even normal submarine depths it's a problem. You might be able to make something work with a chemical gas generator, but then that means you also have what is essentially an explosive device strapped onto the boat.... not exactly desirable. Also, because gas expands with decreased depth control is very difficult was a system like that. If you can generate enough gas to inflate the bladder at 12000 ft you have far far too much gas if you need it at a shallower depth. More problematically, once you inflate the bladder enough to get positive buoyancy at depth, it will begin to expand as the depth and external pressure decreases. This increase buoyancy, which in turn generates a runaway feedback loop. In other words, the vehicle start rocketing to surface until you reach a point where the bladder explodes, at which point the now negatively buoyant vehicle falls back to the bottom. This actually happened in a number of salvage operations in the early 20th century.
I'm not claiming to be an expert, but . . .
I think every single step they did involving resin should have had high vacuum pulled on it before curing. Including ~JB Weld-ing the non-crushy parts to the composite . . . limit finder. Any porosity in that resin is an Achilles' heel when there's 6000 psi of hydraulic pressure to exploit any flaws. Chain porosity enabling penetration would be a death sentence for sure - repeated pressurization fatigues the resin bond, a bit more hidden real estate delaminates, and it's more vulnerable to the next assault from every angle - eventually, <poof>
I'm less sure. Delamination may not be as much of a threat as it would be in most applications because it's compression loading. In tension the resin is critical, but in compression it's all squished together. Large amounts of delamination is undoubtedly a problem, but I suspect it's fairly tolerant to small scale damage.
How much do you think 3 miles of cable weights? Also have to consider waves/tides - water surface moves a considerable amount relative to the bottom. Early unmanned vehicles were done exactly this way, and this is how Titanic and a number of other deep water wrecks were found. You also see many examples of where the vehicle was run into the bottom because of wave motion, and problems with broken machinery elsewhere. Never a very precise way to maneuver either with the length of cable and dynamics.
Treefrog
Book Wheeler
So, you are saying to use a parachute underwater to go up? Excess gas just slips out
I was referring to small-scale, localized delamination where ~6ksi pushes outward into the composite matrix from its foothold in the theoretical chain porosity (string of small pores, even .010" / 0.25mm diameter, with near-zero wall thickness of resin between). Any layup or epoxy joint they didn't cure under high pressure an/or after high vacuum will have 10-100x the pore sizes it could have. At that level of performance demand, your composites need to be ~flawless.
gt1guy
Apparently a racist
Off topic but interesting non the less.
Here's something to blow your mind.
If you were to scuba dive to the Titanic ( forget the simple fact that you'd never make it) you would need .164% O2 in your breathing mix. Helium wouldn't even work for the inert gas, so the other gas would have to be .99.563% Hydrogen. They've done tests down to 2700ish feet and everyone of the test subjects were fucked up after and a few killed themselves after the fact.
.164% O2 at that depth (.6PPO2) is still over 5 times the amount of 02 we're breathing at the surface. The part that sucks is that .767% O2 brings brings it up to a 2.6 PPO2 and you'll be heading for oxygen toxicity and doing the fish out of water after enough time breathing that high of a PPO2. That's the fucked up part of diving real deep, you're safe parameters get so narrow it's impossible to stay within them.
Fun fact: At 1000ft it feels like you're breathing gas is almost a solid. It's hard to inhale and exhale. Just about any hard work will get you unable to catch you breath. Only way to fix it is to go back to the bell and take off your dive hat. The other thing is that all your joints feel like they are being pushed apart.
I know, cool story
Every single ROV that went down to pick up the pieces of the failed sub, had a cable lifting wire connected to the TMS (tether management system) that was lowered into the water. Every. Single. One. That cable will go through a big shieve on a U-boom to a winch on the deck of the boat. That cable looks like a normal non-twist crane wire, except inside it is packed with 12k volt power wires and fiber optic lines. The boom and winch on the boat is called the LARS (Launch And Recovery System).
The TMS at the end of the cable (known as a cage or dog house or even oddly enough the TMS) has it own power/thrusters/lights/telemetry/beacons/cameras. Everything to let the operators know it's depth, compass heading and exactly where it is in real time.
The TMS will also have the reel for the ROV's teather. It is what pays out and recovers the tether to the ROV. Most of the time the tether will be 2-3 thousand feet long. Though in open water they prefer not to have a ton of tether out to get caught on obstructions. That allows the ROV to move about without a ton of extra shit hanging off it. The TMS is usually kept within a 100' or so of the working depth of the ROV, So if the ROV goes black it's not being lifted very far by its tether,,,,which can be damaged pretty easy.
All the electrical junction boxes on ROV and TMS are filled will non electrical conducting oil. They are not affected by depth and even have compensators connected to equalize the pressure inside them
So to answer your question....yes....they could have done something like that..............but it wouldn't have kept them from becoming dead.
That would technically work, but there's no way to control the speed of the accent. The second it hit the surface, the bags would dump the gas and down it goes again.
All the deep water flotation/buoyancy I've seen offshore have been solid and hard as a rock. They weren't meant to lift something to the surface though. They were meant to keep a sub sea valve assembly or a future tie-in T orientated correctly when a pipeline was set on bottom.
Here's something to blow your mind.
If you were to scuba dive to the Titanic ( forget the simple fact that you'd never make it) you would need .164% O2 in your breathing mix. Helium wouldn't even work for the inert gas, so the other gas would have to be .99.563% Hydrogen. They've done tests down to 2700ish feet and everyone of the test subjects were fucked up after and a few killed themselves after the fact.
.164% O2 at that depth (.6PPO2) is still over 5 times the amount of 02 we're breathing at the surface. The part that sucks is that .767% O2 brings brings it up to a 2.6 PPO2 and you'll be heading for oxygen toxicity and doing the fish out of water after enough time breathing that high of a PPO2. That's the fucked up part of diving real deep, you're safe parameters get so narrow it's impossible to stay within them.
Fun fact: At 1000ft it feels like you're breathing gas is almost a solid. It's hard to inhale and exhale. Just about any hard work will get you unable to catch you breath. Only way to fix it is to go back to the bell and take off your dive hat. The other thing is that all your joints feel like they are being pushed apart.
I know, cool story
Every single ROV that went down to pick up the pieces of the failed sub, had a cable lifting wire connected to the TMS (tether management system) that was lowered into the water. Every. Single. One. That cable will go through a big shieve on a U-boom to a winch on the deck of the boat. That cable looks like a normal non-twist crane wire, except inside it is packed with 12k volt power wires and fiber optic lines. The boom and winch on the boat is called the LARS (Launch And Recovery System).
The TMS at the end of the cable (known as a cage or dog house or even oddly enough the TMS) has it own power/thrusters/lights/telemetry/beacons/cameras. Everything to let the operators know it's depth, compass heading and exactly where it is in real time.
The TMS will also have the reel for the ROV's teather. It is what pays out and recovers the tether to the ROV. Most of the time the tether will be 2-3 thousand feet long. Though in open water they prefer not to have a ton of tether out to get caught on obstructions. That allows the ROV to move about without a ton of extra shit hanging off it. The TMS is usually kept within a 100' or so of the working depth of the ROV, So if the ROV goes black it's not being lifted very far by its tether,,,,which can be damaged pretty easy.
All the electrical junction boxes on ROV and TMS are filled will non electrical conducting oil. They are not affected by depth and even have compensators connected to equalize the pressure inside them
So to answer your question....yes....they could have done something like that..............but it wouldn't have kept them from becoming dead.
That would technically work, but there's no way to control the speed of the accent. The second it hit the surface, the bags would dump the gas and down it goes again.
All the deep water flotation/buoyancy I've seen offshore have been solid and hard as a rock. They weren't meant to lift something to the surface though. They were meant to keep a sub sea valve assembly or a future tie-in T orientated correctly when a pipeline was set on bottom.
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sdmuleman
Red Skull Member
More of less how subs do it - ballast tanks are open to water at the bottom, so excess air can escape. On the other hand, they also have other systems to maintain control.
When used for salvage work, what is usually done is to have large bleed off valves, and then use air to provide only a portion of the lift and then a large crane or similar from the surface for the rest. Thus you don't need a crane big enough to lift the entire thing, but can also positively control it to not go up any faster than you want by controlling crane hoist.
Agree in general, but I have difficulty with the mechanism where that leads to catastrophic failure without significant leakage. Seems likely to me that the overall effect would be progressive saturation of pores moving inward, and eventually these would connect to the inner skin and cause leakage into the people tank. Even if there's saturation and porosity as long as the individual pores are fairly small it should not compromise the bulk structural strength that badly. Or put another way, it seems like before you could get enough progressive damage to impact the bulk strength you'd have significant enough leakage through the hull to cause problems that way. Remember too there's a theoretical 1.5 factor of safety - so there should be a fair amount of damage tolerance.
The other aspect of this theory I have trouble with is that damage should be a progressive function of time and pressure. Progressive damage from porosity would take time to occur, so it seems unlikely the hull would sufficiently resist several dives with ~4 hrs on the bottom, but then suffer sufficient additional damage during the decent to collapse before even seeing max pressure.
I just came across this - "Real Engineering" Yoot Hoob Dood analysis:
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gt1guy
Apparently a racist
GM Guy
rollin' along...
On spheres and tolerance, and how symetrical they want it (approx at the 10m30s mark).
Building a deep sea submersable with safety in mind;
Building a deep sea submersable with safety in mind;
aczlan
Good Morning!
Makes sense. Ballast to be very slightly negative and you also aren't straining the crane/hoist as much as lifting the whole weight would?
If the leaked transcript is accurate, they may have had a water leak (possibly into the "equipment" section?), it said they they were going down significantly faster than normal (based on timestamps/depths), kept going down when they dropped the weights/frame, A power bus was shorting out.
Would going down at a higher than normal rate of speed make hull degradation worse?
Aaron Z
Like a raw egg in the hands of the hulk
Deeper = higher exponentia pressure from the sea on this little ill designed craft, POP goes the WEASEL!!
Deeper = higher exponentia pressure from the sea on this little ill designed craft, POP goes the WEASEL!!
aczlan
Good Morning!
Obviously, deeper is worse, but would increasing pressure faster than normal (ie: making a 4 hour descent in 2.5 hours) be significantly worse as well?
How much excess flotation would it have without ballast?
Could going down too fast have been caused by not calculating the weight of the passengers/gear correctly?
Obviously if it kept going down (or just went to neutral) once they dropped the frame, there was more than just a miscalculation in ballast, but could they have had too much ballast because of passenger/gear weight which then caused them to sink too fast, didn't give the pressure vessels time to acclimate and sprung a leak in something which caused them to sink even faster?
Aaron Z
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Why don’t they just come up with a liquid that people can “breathe” so that they can go down to those depths without needing such a strong pressure vessel? Seems like that would be easier/safer than trying all these exotic materials that don’t work that well to begin with.
Lungs aren't the only parts of our body that aren't designed to function at ~6000 PSI
aczlan
Good Morning!
They have one, but getting it to flow properly, then leave when you want to "surface" hasn't been figured out yet.
There are also (as ExWrench said) other considerations.
Bone marrow for example would need to somehow be pressurized and depressurized to that kind of pressure to avoid it imploding/exploding when pressure changes, to say nothing of your brain, eyes and ears.
Aaron Z
nahmus
Refugee from syrup
When they actually get parts of the sub up, If the problem was the pressure cycling was the issue and the material started to break down would it show if they started cutting and taking samples? Or is he CF just a big pile of hay on the bottom.
aczlan
Good Morning!
From what has been shown of pictures of the parts coming off the ship it looks like the carbon fiber is no longer attached to the titanium end rings. I'm not sure how much of the carbon fiber was recovered / recoverable, I don't know if that has been released by anyone who knows what they brought back up.
Aaron Z
plym49.2
Sasquatch49.2
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If they were taking on water, if it was in the rear in the equipment bay I would expect that they would’ve been out of trim with the stern much lower. That would seem to be some thing they would’ve commented on. So my guess is that the carbon fiber structure was taking on water fairly evenly and that they remained on a even keel on their descent
aczlan
Good Morning!
Would probably depend on if the rear bay was isolated from the rest of the sub, or the water could flow under the floor of the "human section"
Would think that would have been noticable (especially with 2 "experts" in the sub).
Aaron Z
redneckengineered
Angry
From the Trieste Wiki...
"After passing 9,000 metres (30,000 ft), one of the outer Plexiglas window panes cracked, shaking the entire vessel"
I wonder if the Navy had to pressure wash the shit out of the pressure vessel upon return?
"After passing 9,000 metres (30,000 ft), one of the outer Plexiglas window panes cracked, shaking the entire vessel"
I wonder if the Navy had to pressure wash the shit out of the pressure vessel upon return?
plym49.2
Sasquatch49.2
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I believe that they had no through-hull stuff going on. The equipment area aft was separate from the pressure cylinder. They used wireless controls.
aczlan
Good Morning!
How would that work with the titanium skin on the inside of the "barrel" of the pressure vessel and the titanium end caps?
Aaron Z
rugger
TheOrginalMiataGuy
I'd be looking to weld the bells on the end and then wrap the cylinder. That's exactly what I did when I made SS wrapped hydraulic cylinders when I needed to reduce weight.
CarterKraft
Red Skull Member
And while it's the reverse in practice it probably matters "hoop stress" the larger the diameter the larger the force.
aczlan
Good Morning!
True, my point was how are you going to make wireless signals pass through titanium?
Aaron Z
MuntCuffin
Upgrayedded user
Tell it to go around, through the carbon fiber?
Void_of_Light
Keeping I.T. real
Was it ever verified the thimble was still part of the sub? It sure looked like the interior was CF when the pic of the monitor screwed into it surfaced.
CrustyJeep
Well-known member
Sorta like a tubular sub, right?A triangular sub wouldn't benefit from isostatic forces like a sphere would, but that doesn't necessarily mean a triangular sub would implode