Titanic tourist sub goes missing sparking search

[Angelo Farina]

So you are saying there was actual fire? Or just heat, ?

So definitely implosion then a explosion ?

That should be easy to hear underwater.

The secondary explosion always occurs even when inside the volume there is just air, as an elastic response after the compression. It is an elastic bounce.
Of course, if inside the air volume there was ignitable material, a Diesel combustion occurs, making the following explosion more powerful.
When I computed the energy released by the implosion I only accounted for the potential energy due to water pressure. I could make a better evaluation taking into account the presence of 5 human bodies and some equipment inside the air volume, which definitely burned, at least partially (75% of human body is water which does not burn).

 

[Angelo Farina]

BS, UNF / UNC is 60 degrees.

EDIT: Pretty sure NPT and NPST is 60 also.

According to Wikipedia, ISO (metric), NPT and UTS (UNF, UNC) are 60°.
Withworth and British Standard (BS) are 55°:

Thread angle - Wikipedia

en.wikipedia.org

We usually refer to this as a Gas thread.
The DIN thread for regulators is G 5/8" BSP, so it has a 55° angle.

I apologize for the wrong information I posted earlier.
I corrected my previous post.

 

[kissonerga.ccr]

Not sure what scrubber material they were using

I am sure somebody would know – we’ve seen a good level detail on the hull construction already. I would think that the ergonomics of handling / swapping the scrubber inside the very confined internal space would call for something like ExtendAir cartridges, no? Just a thought

 

[kissonerga.ccr]

Non-apparent damage as the initial point of a failure is big problem for carbon fiber composites that are exposed to impacts or rough handling

^^That!^^

I once did a pre-buy inspection of a certain experimental airplane with most of its structure built from carbon fiber, fully monocoque design (all structural loads essentially borne by the skin). Real looker, fantastic thrust/weight ratio. As a prospective owner-pilot, I fell in love instantly. The word from my trusted mechanic, however, was that without a very expensive scan (likely to cost more than the airplane), we would have zero comfort as to the presence of any hidden damage, stress fractures, etc. That was the end of that love story

 

[Wookie]

^^That!^^

I once did a pre-buy inspection of a certain experimental airplane with most of its structure built from carbon fiber, fully monocoque design (all structural loads essentially borne by the skin). Real looker, fantastic thrust/weight ratio. As a prospective owner-pilot, I fell in love instantly. The word from my trusted mechanic, however, was that without a very expensive scan (likely to cost more than the airplane), we would have zero comfort as to the presence of any hidden damage, stress fractures, etc. That was the end of that love story

I have carbon fiber as pretty dashboard accents on my Tundra XSP-X, but that's the extent of my carbon fiber use, for just the reasons you stated. During a sailboat race in Key West while I was there, 2 boats were involved in a collision, one glass and one carbon fiber. They crushed and dumpstered the carbon fiber boat as they could never trust it again. When those boats were put int he travel lift, you'd think they were lifting an egg.

 

[Fibonacci]

The secondary explosion always occurs even when inside the volume there is just air, as an elastic response after the compression. It is an elastic bounce.
Of course, if inside the air volume there was ignitable material, a Diesel combustion occurs,

Were the oxygen cylinders being carried in the crew compartment, maybe under the floor?
That would make a considerable difference in any combustion event

 

[Jafo19D]

I have a carbon fiber mountain bike and I sometimes wonder how many years of punishment can that frame can take

 

[makar0n]

I have carbon fiber as pretty dashboard accents on my Tundra XSP-X, but that's the extent of my carbon fiber use, for just the reasons you stated. During a sailboat race in Key West while I was there, 2 boats were involved in a collision, one glass and one carbon fiber. They crushed and dumpstered the carbon fiber boat as they could never trust it again. When those boats were put int he travel lift, you'd think they were lifting an egg.

And maybe we are getting to the root of the problem here - OceanGate vehemently refused any kind of scan, going so far as to fire the one person who demanded it. And that was when the hull was new, since then it had made lots of trips, been repaired (or replaced), and given that transportation of such thing and the whole getting in/out of the water is rather not easy, probably banged here and there.

 

[Wookie]

Probably from Wiki

 

[makar0n]

Ha well, then question is what kind of tests, perhaps merely referring to the actual dives done in 2018/2019 by OceanGate. Two paragraphs above they seem to be specifically refusing any scans:

David Lochridge, the OceanGate Director of Marine Operations, inspected the Titan as it was being handed over from Engineering to Operations and filed a quality control report in January 2018 in which he stated that no non-destructive testing of the carbon fiber hull had taken place to check for voids and delaminating which could compromise the hull's strength. Instead, Lochridge was told that OceanGate would rely on the real-time acoustic monitoring system, which he felt would not warn the crew of potential failure with sufficient time to safely abort the mission and evacuate. The day after he filed his report, he was summoned to a meeting in which he was told the acrylic window was only rated to 1,300 m (4,300 ft) depth because OceanGate would not fund the design of a window rated to 4,000 m (13,000 ft). In that meeting, he reiterated his concerns and added he would refuse to allow crewed testing without a hull scan; Lochridge was dismissed from his position as a result.[32] OceanGate filed a lawsuit against Lochridge that June, accusing him of improperly sharing proprietary trade secrets and fraudulently manufacturing a reason to dismiss him. The suit was settled in November 2018.[32]

And CEO seems to have insisted that his magical acoustic detection system replaced the scan I believe.