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Tourist submarine exploring Titanic wreckage disappears in Atlantic Ocean

1oddtech said:
Why would they not?
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If they were inside, they would have been blown to pieces, or at least blown around with the rest of the debris.


Elwenil said:
I would guess whatever memory it was saved on would survive. It looks like most of the equipment was in the tail and not in the capsule, so it would be exposed for the most part anyway or at least independent of the main capsule and may have maintained it's integrity.
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Has there been any video from past trips posted that showed video from inside that wasn't a cellphone or handheld camera? Only thing I've seen are the exterior shots looks out toward the Titanic. Those cameras really aren't going to show anything more than a bunch of shit flying. And the chances of recovering whatever little box they may have been saved on? Unless the get lucky and it stayed attached to the bigger chunks of wreckages.


Hey, just send the ROV down to pick up that SD card over there! :laughing:
 
All I'll say is that I would expect some sort of venture like this to be recorded. Yeah, it was a bit rough around the edges, but it would still be a huge event in people's lives and I don't think a camera and a small computer to record video would be out of the question considering it's purpose. I mean, people record weddings and shit, why wouldn't they want to remember their trip to the ocean floor to see the Titanic. Again, it's just an assumption, but I would think it's a very logical one. If it were a scientific vessel, I would expect something more like a "black box" recorder, but since this was a bit more"relaxed", simple video would be more likely.
 
Elwenil said:
All I'll say is that I would expect some sort of venture like this to be recorded. Yeah, it was a bit rough around the edges, but it would still be a huge event in people's lives and I don't think a camera and a small computer to record video would be out of the question considering it's purpose. I mean, people record weddings and shit, why wouldn't they want to remember their trip to the ocean floor to see the Titanic. Again, it's just an assumption, but I would think it's a very logical one. If it were a scientific vessel, I would expect something more like a "black box" recorder, but since this was a bit more"relaxed", simple video would be more likely.
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Wow ! A fucking selfi of yourself being imploded. :eek::eek::eek::eek:
 
At those pressures you would need thousands of frames per second to catch anything. Any data they do find will just go dark.
 
aczlan said:
From what I was reading, it sounded like they put the whole thing on a lathe after they were done and trued the ends up, would they do that if there was a thimble in the end?

Aaron Z
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I don't see why not. They would want the OD at the ends machined perfectly round and square to match the collars.

I'm going off the video of them winding the hull. You can clearly see it being wound over a thimble. That would have stayed with it for ever.

Capture.JPG


You can still see it when they glued the collar to the tube.

Capture.JPG
 
On recording, from what I can see and read between the lines it looks to me like they had two completely separate systems, the life support and controls in the sub and the diving/moving controls outside, I assume that those outside controls also had storage for the outside cameras.
I thought that I heard them say on one video that there were no penetrations through the pressure hull of the sub, and that controls were done via wireless means back to the orange"control box" in the tail (which had motor controllers in it) but I could be wrong (thinking further, I don't see how that could work with the titanium end caps and thimble).

Aaron Z
 
FlatLander said:
View port missing is interesting. Wonder if that could happen during a hull failure implosion.
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Not surprising, and to me suggests the failure was not the viewport. Had this been the source of the failure, I would expect distortion of the fwd end bell, and likely the rear end bell/rear structure of the boat to be destroyed by the resulting jet of water down the axis of the hull. However, if the CF tube failed it would essentially blow the end bells off both ends and blow the porthole out of it's socket. Remember there is little holding the porthole in against internal forces.

To me the most likely scenario is general failure of the cylindrical hull section. Behavior of a structure under external pressure is complex and difficult to model. In particular, what is not typically well understood is that the cylindrical hull section in a body of revolution hull is subject to very significant axial compression in addition to the obvious ring stress, and it essentially acts as a column holding the end bells apart. This in turn means buckling and various difficult to predict instability modes come into play. There is also interaction between hoop stress, axial compression and buckling instability. The junctions between the end bells and cylinder are particularly critical because the different shapes have somewhat different elastic deformation behavior. This is likely exasperated by the mismatch in materials.

Circularity of the hull and tolerances of the mating surfaces is also critical for stress behavior - very slight amounts of error can have significant impacts on the resulting stress field.

Beyond that, behaviors of composite materials in general is complex, and can be difficult to predict. Also don't think there's been much work done on composite materials as pressure vessels under external loading. Submarine use is practically unique in this regard. Also likely significant that composite strength is very dependent on proper assembly/layup/curing, and I am unsure to what degree NDT is effective on this thick of structure.

Highly likely to me this will come back to simple incompetence in engineering not understanding/missing some aspect of complex interaction that results in a factor of safety much closer to 1 than they thought combined with defects in workmanship/materials. Ultimately this traces back to doing graduate level cutting edge engineering with completely inexperienced personnel and deliberately ignoring anyone with actual underwater structures experience.
 
aczlan said:
On recording, from what I can see and read between the lines it looks to me like they had two completely separate systems, the life support and controls in the sub and the diving/moving controls outside, I assume that those outside controls also had storage for the outside cameras.
I thought that I heard them say on one video that there were no penetrations through the pressure hull of the sub, and that controls were done via wireless means back to the orange"control box" in the tail (which had motor controllers in it) but I could be wrong (thinking further, I don't see how that could work with the titanium end caps and thimble).

Aaron Z
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I think they did it that way. Wahrless.
sdmuleman said:
Not surprising, and to me suggests the failure was not the viewport. Had this been the source of the failure, I would expect distortion of the fwd end bell, and likely the rear end bell/rear structure of the boat to be destroyed by the resulting jet of water down the axis of the hull. However, if the CF tube failed it would essentially blow the end bells off both ends and blow the porthole out of it's socket. Remember there is little holding the porthole in against internal forces.

To me the most likely scenario is general failure of the cylindrical hull section. Behavior of a structure under external pressure is complex and difficult to model. In particular, what is not typically well understood is that the cylindrical hull section in a body of revolution hull is subject to very significant axial compression in addition to the obvious ring stress, and it essentially acts as a column holding the end bells apart. This in turn means buckling and various difficult to predict instability modes come into play. There is also interaction between hoop stress, axial compression and buckling instability. The junctions between the end bells and cylinder are particularly critical because the different shapes have somewhat different elastic deformation behavior. This is likely exasperated by the mismatch in materials.

Circularity of the hull and tolerances of the mating surfaces is also critical for stress behavior - very slight amounts of error can have significant impacts on the resulting stress field.

Beyond that, behaviors of composite materials in general is complex, and can be difficult to predict. Also don't think there's been much work done on composite materials as pressure vessels under external loading. Submarine use is practically unique in this regard. Also likely significant that composite strength is very dependent on proper assembly/layup/curing, and I am unsure to what degree NDT is effective on this thick of structure.

Highly likely to me this will come back to simple incompetence in engineering not understanding/missing some aspect of complex interaction that results in a factor of safety much closer to 1 than they thought combined with defects in workmanship/materials. Ultimately this traces back to doing graduate level cutting edge engineering with completely inexperienced personnel and deliberately ignoring anyone with actual underwater structures experience.
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I think you’ve nailed it. We’ll find out in 6 to 24 months when the various agencies complete their $$$$$ analyses.
 
plym49.2 said:
I think they did it that way. Wahrless
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I do as well, completely stupid in my opinion to not have hardwired connections for something that important (not everything, but at the very least your system to control motors should be completely separate from your video system and the system drop the ballast weights should have a hardwired backup control).
From what the one video said, they were having significant issues with the switch in the orange box that controlled signal to the motor controllers...
I wouldn't do that for a critical desktop at work, let alone life safety controls.

Aaron Z
 
Fullsize80cherokee said:
this reminds me of the van life girl who got killed last year, I feel like your guys’ social media feeds are pushing this story as a major distraction
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Perhaps they need to analyze some soil samples from the wreckage site to determine the hull density at time of implosion?
 
sdmuleman said:
I am unsure to what degree NDT is effective on this thick of structure.

Highly likely to me this will come back to simple incompetence in engineering not understanding/missing some aspect of complex interaction that results in a factor of safety much closer to 1 than they thought combined with defects in workmanship/materials. Ultimately this traces back to doing graduate level cutting edge engineering with completely inexperienced personnel and deliberately ignoring anyone with actual underwater structures experience.
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The verification of process does seem to be tough. Some mentioned you couldn't do any NDT on composites which I'm not sure if correct but think the above nails it.
 
aczlan said:
I do as well, completely stupid in my opinion to not have hardwired connections for something that important (not everything, but at the very least your system to control motors should be completely separate from your video system and the system drop the ballast weights should have a hardwired backup control).
From what the one video said, they were having significant issues with the switch in the orange box that controlled signal to the motor controllers...
I wouldn't do that for a critical desktop at work, let alone life safety controls.

Aaron Z
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It's all a risk discussion though. Penetrations through the pressure hull to run cables are also a failure point. If you set up the wireless correctly it should be possible to have pretty high reliability. Also, there's limited ability to control the vehicle in the first place - really all you have is the ability to move around slowly once on the bottom and drop ballast. Not like an airplane where positive control is needed continually to prevent a crash. Could also design in a fail safe system where a loss of comms would automatically drop ballast.

Admittedly, the entire setup reeks of questionable engineering and reliability analysis, but the use of wireless through hull comms is not inherently a bad idea.
 
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Weasel said:
The verification of process does seem to be tough. Some mentioned you couldn't do any NDT on composites which I'm not sure if correct but think the above nails it.
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I don't think that's completely true - info I found suggested you can used 3D UT to find voids/delaminations, but it seems like effectiveness would be impacted by material thickness. Also not sure if that would catch all the defects you'd care about under compression loading.

Other question would be what their hull inspection plan was - I'd want to do NDT inspections on the CF after every dive to make sure there's not any progressive failures but somehow I doubt they did that.
 
sdmuleman said:
I don't think that's completely true - info I found suggested you can used 3D UT to find voids/delaminations, but it seems like effectiveness would be impacted by material thickness. Also not sure if that would catch all the defects you'd care about under compression loading.

Other question would be what their hull inspection plan was - I'd want to do NDT inspections on the CF after every dive to make sure there's not any progressive failures but somehow I doubt they did that.
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We used ultrasonic testing on the Atlas V helium bottles to do the same verification.
 
sdmuleman said:
It's all a risk discussion though. Penetrations through the pressure hull to run cables are also a failure point. If you set up the wireless correctly it should be possible to have pretty high reliability. Also, there's limited ability to control the vehicle in the first place - really all you have is the ability to move around slowly once on the bottom and drop ballast. Not like an airplane where positive control is needed continually to prevent a crash. Could also design in a fail safe system where a loss of comms would automatically drop ballast.

Admittedly, the entire setup reeks of questionable engineering and reliability analysis, but the use of wireless through hull comms is not inherently a bad idea.
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I am still wondering what provisions they had for controlling tilt and trim.
 
plym49.2 said:
I am still wondering what provisions they had for controlling tilt and trim.
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It would appear all they had was hope and arrogance... For virtually everything.

Also, what do we make of this?

1688049178929.png


Just duct tape together to offload, of is that some sort of cover taped over to keep prying eyes from seeing a big ole fracture in the hull?

I assume duct taped to offload.
 
westracing01 said:
It would appear all they had was hope and arrogance... For virtually everything.

Also, what do we make of this?

1688049178929.png


Just duct tape together to offload, of is that some sort of cover taped over to keep prying eyes from seeing a big ole fracture in the hull?

I assume duct taped to offload.
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That looks like the non-pressurized skin of the tail, looks almost like a piece of plastic taped to the side.

Aaron Z
 
westracing01 said:
It would appear all they had was hope and arrogance... For virtually everything.

Also, what do we make of this?

1688049178929.png


Just duct tape together to offload, of is that some sort of cover taped over to keep prying eyes from seeing a big ole fracture in the hull?

I assume duct taped to offload.
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That piece was probably part of the tail and wouldn't have anything to do with structural integrity.
 
sdmuleman said:
if the CF tube failed it would essentially blow the end bells off both ends and blow the porthole out of it's socket. Remember there is little holding the porthole in against internal forces.
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Like crushing a plastic bottle with a loose cap. Path of least resistance.
 
If the porthole was the failure point then the pressure wave would have been a EXlosion not implosion?
I are not real smart and working in vacuums is about the max of my processing power:shaking:

Edit: The obvious size difference of the Limiting factors viewports, they are 15" in diameter at the outside but taper to 3"? while being 7" thick.
Obviously completely different depth rating...

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FlatLander said:
Like crushing a plastic bottle with a loose cap. Path of least resistance.
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No. Not at 5500 psi external pressure. There is no "blow the end bells off" in this scenario. As soon as the CF stopped resisting, those bells either collided at high velocity, or just fell away. There is no force to blow anything outward. The interior of the hull was at a vacuum of 12000 inches of mercury.
 
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