Titanic Sub Missing

[marina_irc]

On CNN they just gave an optimistic interview with someone in St Johns near a ship about equipment ready to leave St John's once the PAPERWORK was cleared and it takes 24 hours to get there by ship, they also mentioned it's waiting at the airport.

Do they have a clue they run out of air in ten hours or less?

This is contextless without understanding what paperwork this individual is referring to. If it's chain of custody paperwork, safety inspections, etc, then this is a critical part of the process which keeps people actually safe while performing highly dangerous activities. Of course, it could also just well be a speculative venture unapproved by the coastguard or any of a countless dozen other things. But imagining some kind of bureaucracy is holding up international rescue at sea over paperwork is just the wrong way to take that. All resources mobilised and requested by the US and Canadian Coastguards will move rapidly through approved channels under preexisting agreements which handle costs and international transfers of materiel and personnel. If those are running slowly, then military channels via NORAD can be resorted to as the USCG is a uniformed service. The USCG is very much the most action-oriented, scrappy and willing to 'do what it takes' of the uniformed services and the Canadians are very practical about these things.

FADOSS can potentially be airdropped to a ship on the scene from a heavy lifter bird -- other than that, to be blunt, the only chance these men have assuming they are still alive is Atalante, with Victor 6000 and the "Maestro" 6dof robotic manipulator arm. If they are trapped in debris, there is a good chance the ROV can free them. If for some reason the Titan cannot reach positive buoyancy, successful recovery is more slim, as it will be difficult to generate sufficient lift forces and sustain them without a FADOSS attachment. It is unlikely the Atalante has lift balloons and the necessary shackles to successfully connect them to the Titan onboard and I'm not sure they could be delivered any faster than FADOSS could get there.

The one thing I will note is that it is unreasonable to assume panicked heavy breathing. More likely the people onboard would be breathing slowly, and the design oxygen levels are in fact conservative. There is almost certainly more time, not less, on the basis of oxygen. My real concerns would be CO2 scrubbing and hypothermia. Still, if there's anything that the history of submarine rescue teaches us, the number of excedances of nominal survival time in which people were actually recovered is rather high; the human body is stubborn.

 

[marina_irc]

Well, it is pretty obvious there should have been regulations governing this type of submersible. And if not, why not? Pretty much the same with the British Board of Trade in 1911/12. Very very sad. I suspect/suppose that the 5 occupants of Titan died due to a catastrophic failure of Titan on it’s decent on Sunday. Very very sad.

I don’t think the USA coastguard has confirmed a 30 minute interval of sound of ‘SOS’ from sonar detectors. Probably bits falling off Titanic or something else. Not the sort of news that would give the families of those involved any hope.

There are regulations, but the "Bounty" loophole* was used: The tourists paying for their ride officially were paying for training, and then were "mission specialists" performing "work". Because they were then officially "crew", there was thus no way for regulators to prevent the dives, as they were experiments on an experimental submersible manned only by the crew.

*The Sailing Vessel Bounty that was lost during Hurricane Sandy 100 miles off Cape Hatteras was not legally a ship for purposes of conveying passengers, but rather only licensed as a tourist attraction which could execute non-revenue moves from port to port. The owners then essentially sold experiential "be a member of the crew" opportunities to people who wanted to live a historic sailing lifestyle. Though the physical circumstances are quite different, the legal loophole is more or less the same. Perhaps it will finally be closed.

 

[Gordon Mooneyhan]

I believe the biggest safety issue that Lochridge and others raised with the Titan was the safety rating of its viewport, which is certified to only 1300 meters max, whereas the wreck is at around 4000 meters. From the pictures that George Jacub posted in Post #44 of this thread, the viewport appears to be a separate 380mm acrylic unit fixed to the main composite hull. Does anyone know how this fixation is done? Is it something similar to the hyperglue that some Airbus aircraft used? I ask because if the viewport failed at the join, then it would be immaterial how good and resilient the composite material used for the main hull had been.

Arun,

I think that if the viewport failed, it would most likely not have happened at the joint. The rivets, or whatever makes the connection with the hull, would seem to be one of the stronger points on the Titan. I suspect the failure would occur somewhere on the surface of the viewport.

 

[marina_irc]

Arun,

I think that if the viewport failed, it would most likely not have happened at the joint. The rivets, or whatever makes the connection with the hull, would seem to be one of the stronger points on the Titan. I suspect the failure would occur somewhere on the surface of the viewport.

I'd add that it's also important to understand exactly what the issue with the viewport was. It was sized, with material of the appropriate strength, for 4,000 meters. But it was not tested, it was not validated, to the required strength reserves and demonstrated qualities in NDT (non-destructive testing) to be certified to 4,000 meters. In particular, a factor of safety is often in part a function of uncertainty in the design; the greater the uncertainty, the higher the factor of safety (when you are prudent). If it had only been sized for 1,300 meters, we wouldn't be having this conversation because the Titan would have been lost on its first dive past that depth. What happened was that Ocean Gate wanted to procure the viewport without the tests, verification, chain of custody, etc which are required to guarantee it met manufacturing standards and tolerances sufficient to allow for a low factor of safety. The vendor said "your thickness and your verification checks correspond to a Factor of Safety which means we only certify to 1,300 meters". Ocean Gate said to the effect of: "well, I calculated the thickness and it's good enough."

And this is why it could function over and over -- and then potentially abruptly fail.

 

[samson]

I'd add that it's also important to understand exactly what the issue with the viewport was. It was sized, with material of the appropriate strength, for 4,000 meters. But it was not tested, it was not validated, to the required strength reserves and demonstrated qualities in NDT (non-destructive testing) to be certified to 4,000 meters. In particular, a factor of safety is often in part a function of uncertainty in the design; the greater the uncertainty, the higher the factor of safety (when you are prudent). If it had only been sized for 1,300 meters, we wouldn't be having this conversation because the Titan would have been lost on its first dive past that depth. What happened was that Ocean Gate wanted to procure the viewport without the tests, verification, chain of custody, etc which are required to guarantee it met manufacturing standards and tolerances sufficient to allow for a low factor of safety. The vendor said "your thickness and your verification checks correspond to a Factor of Safety which means we only certify to 1,300 meters". Ocean Gate said to the effect of: "well, I calculated the thickness and it's good enough."

And this is why it could function over and over -- and then potentially abruptly fail.

Is your theory that the viewport failed? I know everything is still speculation at this point but I'm still trying to guess what happened. Wouldn't a failed viewport cause an implosion that would be picked up on sonar from the mothership?

 

[samson]

Crazy how so many are now denying involvement with OceanGate. The University of Washington and now Boeing came out with a statement saying they were not at all involved with the design and build of Titan.

 

[marina_irc]

Is your theory that the viewport failed? I know everything is still speculation at this point but I'm still trying to guess what happened. Wouldn't a failed viewport cause an implosion that would be picked up on sonar from the mothership?

I don't have a theory for the exact failure mechanism. The hull seems as suspect as the viewport; remember all the problems Boeing had with carbon fibre composite quality control to aviation standards in the early days of the 787 programme. This is a more demanding application.

As for the implosion being detected, remember that the internal space on the submersible is very small, so the acoustic signature will be correspondingly small, orders of magnitude less than a full sized nuclear submarine like Kursk or Thresher. The mothership is unlikely to have sophisticated noise detecting hydrophones; it is chartered for this application and was originally a Canadian Coast Guard ship, now owned by a private company. Finally, people with sophisticated equipment may nominally detect it, but then have to sort through a lot of garbage data to actually identify the sound of interest, and possibly perform multiple filtering steps to be able to properly resolve what they're looking for. There's a big difference between having a recording of big data from a hydrophone for a region of the ocean and being able to understand and interpret what that data is telling you, and that effort is normally focused on specific known targets, or retrospectively when a recording demonstrates something of interest. If the Titan was lost to an implosion I expect someone heard it -- but we will only know when reviewing and processing logs weeks or months later. And acoustic propagation in the ocean varies tremendously between different ocean layers, with the larger number of layers the deeper you go increasing the uncertainty. There are calcuations which can explain all of this, but to be frank, most people wouldn't be interested in discussing them in detail because they all involve fourier transforms and differential equations.

 

[Arun Vajpey]

I don’t understand why if Titan got to the sea surface it would not have some kind of tracking device to enable it’s location to be detected.

Probably a question of saving money. There is only so much they could have done with safety measures when they were charging only $250,000 per head per trip.

 

[Matthew Q]

... We put a man on the moon in 1969 but it was over five decades until "paying passengers were allowed in "space". Many adventurers in many venues understand safety but sometimes push the edges of that safety. I do not know enough about engineering to have a clue how safe was this submersible trip to the Titanic.

It's worth noting that space is empty. Getting there is a trick, but once you're there, the stresses aren't too severe.
The bottom of the ocean is much worse. Constant, unrelenting strain is placed on equipment down there. It's a much greater challenge.

 

[chrismireya]

And this is why it could function over and over -- and then potentially abruptly fail.

This is why stress testing is so vital. Testing a potential submersible can not only test if a design is viable for target depths (with associated pressures), but it can also determine long-term stress from repeated use.

My dad assisted with a jet that is currently in use by the U.S. Navy. It went through many rigorous tests -- to the point of destroying prototypes (i.e., "destructive testing"). These tests included structural stress tests associated with carrier/tail hook landings. Not only did the tail hook and the fuselage structure need to survive such harsh, repeat testing, but so did EVERY component that would be included on the jet. This is how real-world point-of-failure could be identified.

I imagine that the same is true with nautical engineering. This was one point of contention in David Lochridge's lawsuit against OceanGate.

At this point, the seven resurfacing redundancies built into Titan (including the no-power scenarios) should result with the vessel being somewhere on the surface. This doesn't seem to be the case. At this point, I think that it would be somewhere in the vicinity of its carrier ship. If it isn't on the surface, then the remaining scenarios are bleak:

1.) It could have continued its mission to Titanic (without comms) and somehow become snagged/trapped;
2.) It could have lost power and its no-power redundancy failed (meaning it is sitting somewhere on the ocean floor); or,
3.) It imploded.

I'm hoping for a miracle. I hope that the sound of knocking/banging is from Titan. I hope that it is floating somewhere on the surface -- and is found in time.

However, given the little that the public has been told, it seems like the most likely scenario is #3. There was no communication at roughly 1:45.00 into the descent. If, as some outlets have reported, Titan was supposed to try to send a message every 15 minutes during descent, then it seems like something went catastrophically wrong during the descent.

I realize that speculation isn't necessarily good at this point of search and rescue (but it's part of our nature).
I hope that I am wrong.

 

[Harrison Bland]

Do submersibles to the wreck site have a designated safe landing zone that’s known to be free of debris, or do they just drop down in the general vicinity of the wreck and hope they don’t land on a broken chunk of hull?

 

[Arun Vajpey]

No recent updates.

If the Titan is still intact and its occupants alive, we are only a few hours away from a critical air situation even with the best case scenario. Remember that the "96 hours" is only an estimate and relies on the occupants' breathing pattern. Also, how effective the CO2 brushers are; if the carbon-dioxide levels within rise, the rate of breathing invariably increases and with that the oxygen consumption.

I think realistically we have to prepare for the worst. I now wish that it was a catastrophic hull failure, in which case it would all have been over in a second.

Wouldn't a failed viewport cause an implosion that would be picked up on sonar from the mothership?

I expect it would in theory. But it also depends on exactly what was happening at the precise moment communication was lost as a result of a catastrophic hull failure. If the previous routine signal had been only a minute or two before, there is the possibility that the crew on the mothership missed the one from the implosion before they even realized that they had lost communication with the Titan.

IF there was a hull failure with implosion, what are the chances of finding any debris to aid investigation to reduce the chances of something like this happening again?

 

[PeterChappell]

It's a bit of a coincidence, but I recorded the film on the Kursk submarine disaster a few weeks ago and I've been watching parts of it from time to time. This morning I reached the part where the British are offering help. The Admiral says, "the Russians have only built 3 submersibles capable of helping, one is having repairs in the Black Sea, another is just a collection of bolts, the other the Mir was sold of to the West for rich people to go down and see the Titanic"! The Mir's really exist, but they seem to have been mainly used for exploration & science including Cameron's Titanic film!

 

[bewnyc]

Missing Titanic sub projected to run out of oxygen just after 7 a.m.​

The French government delivered its Victor 6000, a robot capable of diving 20,000 feet below sea level, to the area Titan vanished at around 6 p.m. Wednesday, with just 13 hours to scan the area for the missing sub.

The unmanned robot — which is one of the few vessels in the world capable of descending to the 12,000-feet-deep resting place of the Titanic — is equipped with a mechanical robot arm that could help drag the Titan back to the surface.

 

[PeterChappell]

If they are trapped in debris, there is a good chance the ROV can free them. If for some reason the Titan cannot reach positive buoyancy, successful recovery is more slim, as it will be difficult to generate sufficient lift forces and sustain them without a FADOSS attachment. It is unlikely the Atalante has lift balloons and the necessary shackles to successfully connect them to the Titan onboard and I'm not sure they could be delivered any faster than FADOSS could get there.

How much force can the ROV apply, and in which direction? If trapped on the muddy seabed, they will need a substantial force to move it, because normal rules of buoyancy don't apply until the water gets underneath the craft. This is the case even if there is no debris covering it, and the ballast weights are not holding it down.