Titanic tourist sub goes missing

[WLJ]

Has anyone seen anything on whether or not the every 15 minute "phone home" pings were done automatically or manually?
Reason I ask is if done manually and something happened to the air supply and incapacitated the crew that could explain the loss of contact and the lack of a emergency weight drop.

Just trying to come up with other possibilities other than implosion. Not discounting implosion but think other possibilities should be explored as well.

[dogmush]

What happened to the air supply is it was replaced with sea water at high pressure.

Boomhauer I think has nailed it, that bitch had a catastrophic leak that filled her and sank her faster than a coms message could be sent out.  Odds are very high everyone on board died before they were even noticed missing. 

I also agree that when they find the wreck, it's likely to show wither the port failed, or the hatch seals.

[WLJ]

I'm still thinking implosion is the most likely explanation and have from the start. Just think we shouldn't blind ourselves to other possibilities.

[WLJ]

I also agree that when they find the wreck, it's likely to show wither the port failed, or the hatch seals.

If an implosion did occur may not be enough left intact for that. Pieces could be so intermingled with the Titanic debris field we may never find much if anything.

[dogmush]

Implosion is, IMHO, less likely.

For it to implode, the pressure hull would have to fail at a depth significantly shallower than it's test and previous dives.  Sure, that could happen, but the hull itself is actually pretty well designed and 5" of carbon composite is strong enough to hold the pressure barring damage.

I'm assuming what caused the sinking also caused the commo loss (Occam's razor and all that), so whatever happened happened 1.5 to 1.75 hours into the dive, which shoulf have been only(?!?) 6000 or so feet deep.

On the other hand, is she sprung a leak, either a failed hatch seal (or improperly sealed hatch) or the aforementioned not quite up to snuff porthole, then the water would rapidly start filling up the hull, decreasing buoyancy and speeding up the descent.  Things would rapidly accelerate as the sub got heavier, and more air was replaced by water, but by the time she got to hull crush depth the inside would be full of water, and the pressures equalized, so no implosion.  If that porthole gave way, all that would have happened in seconds.

So that's my money:  She sprung an unsurvivable leak that filled the inside with water and she sank from about halfway into the dive. She's probably sitting half buried in the muck she augured into full of water and 5 bodies.  But that's just me betting on the odds. 

[Northwoods]

Assuming implosion.  Whether we find debris, and in quantity sufficient to determine the cause of the failure will depend largely on how far from the bottom the failure occurred.  If they were basically on the bottom then the debris field should be fairly compact depending on the currents and size/weight of the debris.  If they were 1/2-3/4 of the way down, so still several thousand feet above the bottom the debris field could be many miles long.  And with such a small vessel you’d only ever find the biggest pieces.

[WLJ]

Breaking Debris field found - US Coast Guard

A debris field has been discovered within the search area by an ROV near the Titanic, the US Coast Guard has just announced.

Experts within the unified command are evaluating the information.

We will bring you more details shortly.

https://www.bbc.com/news/live/world-us-canada-65967464?ns_mchannel=social&ns_source=twitter&ns_campaign=bbc_live&ns_linkname=64946dc7f2e5745fd8a782db%26Debris%20field%20found%20-%20US%20Coast%20Guard%262023-06-22T15%3A50%3A32.421Z&ns_fee=0&pinned_post_locator=urn:asset:021873ea-55df-41f9-9de5-926aaf985678&pinned_post_asset_id=64946dc7f2e5745fd8a782db&pinned_post_type=share

[Ben]

I'm assuming what caused the sinking also caused the commo loss (Occam's razor and all that), so whatever happened happened 1.5 to 1.75 hours into the dive, which shoulf have been only(?!?) 6000 or so feet deep.

Though again, if they used the same transponders that other ROVs and AUVs use, it would be a tube 3" diameter by 20" or thereabouts attached to the outside of the hull and with an independent internal power source. If sinking caused commo loss, the transponder should take a licking but keep on ticking. That both the transponder and commo went out is what leads me to believe catastrophic event.

Although also again, these guys are appearing not to be the sharpest knives in the drawer, so who know if they were using "best practices" for the transponder. We already saw they weren't with the ridiculous 15 minute ping intervals.

As to the manual vs automatic question, transponders are programmed, so basically automatic.

[WLJ]

Implosion is. IMHO. less likely.

For it to implode, the pressure hull would have to fail at a depth significantly shallower than it's test and previous dives.  Sure, that could happen, but the hull itself is actually pretty well designed and 5" of carbon composite is strong enough to hold the pressure barring damage.

I'm assuming what caused the sinking also caused the commo loss (Occam's razor and all that), so whatever happened happened 1.5 to 1.75 hours into the dive, which shoulf have been only(?!?) 6000 or so feet deep.

On the other hand, is she sprung a leak, either a failed hatch seal (or improperly sealed hatch) or the aforementioned not quite up to snuff porthole, then the water would rapidly start filling up the hull, decreasing buoyancy and speeding up the descent.  Things would rapidly accelerate as the sub got heavier, and more air was replaced by water, but by the time she got to hull crush depth the inside would be full of water, and the pressures equalized, so no implosion.  If that porthole gave way, all that would have happened in seconds.

So that's my money:  She sprung an unsurvivable leak that filled the inside with water and she sank from about halfway into the dive. She's probably sitting half buried in the muck she augured into full of water and 5 bodies.  But that's just me betting on the odds.

At 12,000 ft it's pretty much an all or nothing affair. No real such thing as a small leak at those depths

[WLJ]

Assuming implosion.  Whether we find debris, and in quantity sufficient to determine the cause of the failure will depend largely on how far from the bottom the failure occurred.  If they were basically on the bottom then the debris field should be fairly compact depending on the currents and size/weight of the debris.  If they were 1/2-3/4 of the way down, so still several thousand feet above the bottom the debris field could be many miles long.  And with such a small vessel you’d only ever find the biggest pieces.

If the above debris "field" found report pans out we'll see

[WLJ]

More

Coast Guard to give update on debris field at 15:00 local time

With the breaking news of a debris field being found in the search, US Coast Guard has announced it will hold a press conference at 15:00 local time (20:00 GMT).

A statement from the Coast Guard says the Horizon Arctic’s ROV (remotely operated vehicle) found debris on the sea floor near the Titanic wreck.

Rear Adm. John Mauger, the First Coast Guard District commander and Capt. Jamie Frederick, the First Coast Guard District response coordinator, will be speaking.

Edit: 15:00 EST (03:00pm) When they say local time I guess they mean Boston not New Newfoundland.

https://www.bbc.com/news/live/world-us-canada-65967464?ns_mchannel=social&ns_source=twitter&ns_campaign=bbc_live&ns_linkname=649470571babaa614a472eb4%26Coast%20Guard%20to%20give%20update%20on%20debris%20field%20at%2015%3A00%20local%20time%262023-06-22T16%3A06%3A57.896Z&ns_fee=0&pinned_post_locator=urn:asset:4dd9dd6f-3b87-4ded-8079-cd29e9ce415f&pinned_post_asset_id=649470571babaa614a472eb4&pinned_post_type=share

[230RN]

Jeeze, I hope it wasn't my guns.



(Tasteless but irresistible joke... sorry!)

We'll see what happens at the CG conference, but it's looking like it was sudden, thank G-d.

[WLJ]

Lets be clear here
It's a reported debris field and may have nothing to do with the Titan.

But the fact they've already scheduled a news conference makes me wonder. Could have been a previously scheduled update though

[BobR]

Lets be clear here
It's reported debris field and may have nothing to do with the Titan.

But the fact they've already scheduled a news conference makes me wonder. Could have been a previously scheduled update though

Looking at ADSB exchange I don't see any aerial searching underway in the area and there is a CG plane headed from Newfoundland back to the SW (Boston?). There is a possibility they have stopped the surface search already. Even if the debris field is not the submersible they are looking for the odds of them still being alive is about none to nearly none IMO. Of course, the O2 estimates were based on 5 people exchanging O2 for CO2, less people would make it last longer if anyone were alive. Sounds like a movie plot.

bob

bob

[WLJ]

Looking at ADSB exchange I don't see any aerial searching underway in the area and there is a CG plane headed from Newfoundland back to the SW (Boston?). There is a possibility they have stopped the surface search already. Even if the debris field is not the submersible they are looking for the odds of them still being alive is about none to nearly none IMO. Of course, the O2 estimates were based on 5 people exchanging O2 for CO2, less people would make it last longer if anyone were alive. Sounds like a movie plot.

bob

bob

I've check FlightRadar24 a few times and never saw any on site search aircraft show up.

[Northwoods]

Looking at ADSB exchange I don't see any aerial searching underway in the area and there is a CG plane headed from Newfoundland back to the SW (Boston?). There is a possibility they have stopped the surface search already. Even if the debris field is not the submersible they are looking for the odds of them still being alive is about none to nearly none IMO. Of course, the O2 estimates were based on 5 people exchanging O2 for CO2, less people would make it last longer if anyone were alive. Sounds like a movie plot.

bob

bob

Unless they started killing folks not much they could do to extend the O2 supply, if they were alive after comm loss and before this morning.

If they were on the surface and they had some means to get fresh air they could still be alive.

But, the debris field, and circumstantial evidence before it was found pointed to a sudden catastrophic failure shortly after the last ping.

[dogmush]

Addendum to my above post:

I just finished listening to a twitter space with some submersible design experts from Woods Hole (I think they said).  They talked about the brittleness of the carbon composite causing basically very small stress fractures on each dive, which would lead to a catastrophic pressure hull failure (implosion) at significantly less than test depth.  Basically, where metal is elastic and squeezes and gets bigger, the composites will crack a little bit every time they are compressed until they give unexpectedly.  They said it was very tricky to get the composite just right to avoid this.

I'm not a materials engineer, so I'll take that expert at his word.  This puts the likelihood of an implosion during the descent phase as the new "most likely" explanation. If that's the case, and it jives with a large-ish debris field on the bottom, I'm not sure anyone will bother to try and raise enough pieces to definitively say either way.  At least it would have been quick.

[WLJ]

Addendum to my above post:

I just finished listening to a twitter space with some submersible design experts from Woods Hole (I think they said).  They talked about the brittleness of the carbon composite causing basically very small stress fractures on each dive, which would lead to a catastrophic pressure hull failure (implosion) at significantly less than test depth.  Basically, where metal is elastic and squeezes and gets bigger, the composites will crack a little bit every time they are compressed until they give unexpectedly.  They said it was very tricky to get the composite just right to avoid this.

Recall seeing that mentioned in one or more of the news articles I scanned where they were criticizing the building of the sub.

[Northwoods]

Addendum to my above post:

I just finished listening to a twitter space with some submersible design experts from Woods Hole (I think they said).  They talked about the brittleness of the carbon composite causing basically very small stress fractures on each dive, which would lead to a catastrophic pressure hull failure (implosion) at significantly less than test depth.  Basically, where metal is elastic and squeezes and gets bigger, the composites will crack a little bit every time they are compressed until they give unexpectedly.  They said it was very tricky to get the composite just right to avoid this.

I'm not a materials engineer, so I'll take that expert at his word.  This puts the likelihood of an implosion during the descent phase as the new "most likely" explanation. If that's the case, and it jives with a large-ish debris field on the bottom, I'm not sure anyone will bother to try and raise enough pieces to definitively say either way.  At least it would have been quick.

That is correct about composites.  Hence why safety critical composites are life limited usually, and often require regular (non destructive) inspections.  Fatigue analysis is tricky with metals due to the large amount of scatter in the data.  Composite materials, due to the process dependent nature of their strength properties is even worse for analysis accuracy.  So large safety factors are needed, and/or frequent inspections.

[WLJ]

Got curious about what other ships have sunk in that area and came across this site
zoom in and out as needed. Ship names appear if you zoom in enough

Sunken Ships of the Second World War
https://mapsterman.maps.arcgis.com/apps/dashboards/fe88b5e18c6443c7afaf6e32f8432687

[dogmush]

OceanGate claims in it's blurbs that the Titan had some kind of integrated hull health sensor system.  I'd be interested in an acedemic way on what that was and how it worked.

I tried to go to their website and get the exact verbage they used, but their site is down.

[MillCreek]

That is correct about composites.  Hence why safety critical composites are life limited usually, and often require regular (non destructive) inspections.  Fatigue analysis is tricky with metals due to the large amount of scatter in the data.  Composite materials, due to the process dependent nature of their strength properties is even worse for analysis accuracy.  So large safety factors are needed, and/or frequent inspections.

Would this also apply to aircraft components, like the composite fuselage of the Boeing 787?  It is not seagoing, but there is pressure cycling during ascents and descents.

[WLJ]

Confirmed Titan debris

Breaking' Landing frame and a rear cover from the submersible' among the debris

We have just had an update from dive expert David Mearns, who says the debris includes "a landing frame and a rear cover from the submersible".

Mearns is a friend of passengers aboard the Titan.

David Mearns has told the BBC that the president of the Explorers Club (which is connected to the diving and rescue community), says the debris includes "a landing frame and a rear cover from the submersible".

https://www.bbc.com/news/live/world-us-canada-65967464?ns_mchannel=social&ns_source=twitter&ns_campaign=bbc_live&ns_linkname=6494841bf2e5745fd8a78300%26%27Landing%20frame%20and%20a%20rear%20cover%20from%20the%20submersible%27%20among%20the%20debris%262023-06-22T17%3A25%3A47.784Z&ns_fee=0&pinned_post_locator=urn:asset:bdcc76ef-88b0-4781-ac13-4a44dec7419b&pinned_post_asset_id=6494841bf2e5745fd8a78300&pinned_post_type=share

[K Frame]

"some kind of integrated hull health sensor system."

Taken from an XBox or a Play Station?

[cordex]

OceanGate claims in it's blurbs that the Titan had some kind of integrated hull health sensor system.  I'd be interested in an acedemic way on what that was and how it worked.

I tried to go to their website and get the exact verbage they used, but their site is down.

https://web.archive.org/web/20230619165742/https://www.oceangate.com/our-subs/titan-submersible.html

Real-Time Health Monitoring
The most significant innovation is the proprietary real-time hull health monitoring (RTM) system. Titan is the only manned submersible to employ an integrated real-time health monitoring system. Utilizing co-located acoustic sensors and strain gauges throughout the pressure boundary, the RTM system makes it possible to analyze the effects of changing pressure on the vessel as the submersible dives deeper, and accurately assess the integrity of the structure. This onboard health analysis monitoring system provides early warning detection for the pilot with enough time to arrest the descent and safely return to surface.