[PSUBS-MAILIST] Titan submersible missing at Titanic site

Tue Jun 20 17:04:23 EDT 2023

I have to admit my heart sank when I read the hull was carbon fibre.  This might not be the only problem, seems they may have been gambling on a much lower viewport safety factor as well.

"the viewport at the forward of the submersible was only built to a certified pressure of 1,300 meters, although OceanGate intended to take passengers down to depths of 4,000 meters. Lochridge learned that the viewport manufacturer would only certify to a depth of 1,300 meters due to experimental design of the viewport supplied by OceanGate, which was out of the Pressure Vessels for Human Occupancy (“PVHO”) standards."

That was from a whistle blower complaint from 2018:
https://newrepublic.com/post/173802/missing-titanic-sub-faced-lawsuit-depths-safely-travel-oceangate

Ian.

-----Original Message-----
From: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Jun 20, 2023 9:17 AM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site

Ian a friend of mine tested such a hull (Carbon zylinder with titan endcaps) in April. 
Design calculation was for 6000 m - but collaps half way. 

- The Titan sub has no entrance hatch 
- no dive tanks (can not really surface) 
- the larges Carbon- Titan pressure hull build
-11 dives. 
- no certifications
- an Toy-Controller

The lost of contact after just 1:46 h and the lost  of the pressurehull of my friend in April indicate 
a catastrophic senario. But if the boat impolde - sombody at the navy will have the soundings.

First question should be to the navy - any seismic soundings?

vbr Carsten 

-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
Datum: 2023-06-20T02:45:52+0200
Von: "Ian Juby via Personal_Submersibles" <personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>

So do any of you guys have a pressure hull of fiberglass or carbon fiber? I've been pondering this over in my head. The Titan's carbon fiber hull is, I believe, unique to deep submersibles. It also had this very sophisticated sensor system all over the hull, monitoring its health. The thing is, carbon fiber has no give - it simply catastrophically fails. This is the issue with using it on aircraft - it doesn't bend like metal does, it breaks. So what exactly does this hull sensor system look for or listen for? And if it detected problems? I don't think it would make any difference at all by that point - the hull would have failed long before the pilot had a chance to ascend to relieve pressure. I would think the time between the sensors detecting a problem and the hull catastrophically collapsing would be, at most, 10ths of a second. But I could be wrong - I just base that on my experience with the stuff.They were 1:45 into a 2-1/2 hour descent when contact was lost - so they hadn't even made it to the bottom yet - but still hitting over 9,000 feet. That's some pretty serious depth already. It's unlikely they made it to the Titanic and got entangled or trapped in the wreck somehow because it gets its navigation from the surface ship. So if communication is lost, they are also lost in terms of navigation. This is precisely what happened last year when that CBS reporter was aboard. The pilot on yesterday's dive would have scrubbed the dive if they had lost comms and thus navigation.
Also let's bear in mind the loss of the Thresher - there was some kind of thermal plane at about 100 foot depth that kept both the Thresher and the Seawolf (the submarine trying to find the Thresher) from communicating with surface ships. Is it possible the Titan encountered some kind of thermal plane similar to that which disrupted their communications? But the fact that they still haven't had contact in a day and a half is telling me this is a recovery operation, not rescue.  :(

Just spitballing here - am I off the mark? Have any of you guys had a composite pressure hull?
Ian

On Mon, Jun 19, 2023 at 6:25 PM Douglas Suhr via Personal_Submersibles <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)> wrote:
Thank you everyone for the info on this sub and her current situation. The fact that they are bolted into the pressure hull from the outside is a bit eerie, but it sounds like there's a lot of redundancy when it comes to surfacing. Hopefully the next 12 hours will bring good news. ~ Doug S. 

On Mon, Jun 19, 2023 at 6:12 PM irox via Personal_Submersibles <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)> wrote:

I believe the hull is made of carbon fiber and the submersible wasn't certified any regulatory body (ABS/Lloyds/etc).

This video gives some idea of the operation:
https://www.youtube.com/watch?v=29co_Hksk6o

They read the waiver terms and conditions at 2:40 mark.  At the 7:27 mark they show a previous expedition where they lose communication with the sub and it gets "lost" (since it depends on topside of navigation data) for a couple of hours.

Hoping for the best.

Ian.

-----Original Message-----
From: Personal Submersibles General Discussion <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)>
Sent: Jun 19, 2023 2:17 PM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)>
Subject: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site

I'm sorry to hear this news. Hoping and praying the sub is found quickly with no loss of life! What do we know about the Oceangate Titan submersible? Hopefully at least 72-hrs of life support for its five occupants? ~ Doug S. 

On Mon, Jun 19, 2023 at 3:58 PM Jon Wallace via Personal_Submersibles <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)> wrote:

I agree.

Jon

On Monday, June 19, 2023 at 03:18:23 PM EDT, via Personal_Submersibles <personal_submersibles at psubs.org (mailto:personal_submersibles at psubs.org)> wrote:

https://www.bbc.com/news/world-us-canada-65953872 (https://www.bbc.com/news/world-us-canada-65953872)
Looks not good..

Emile D.L. van Essen

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