[PSUBS-MAILIST] Titan submersible missing at Titanic site

Sat Jul 1 15:53:12 EDT 2023

The Titan Submersible Implosion Was “an Accident Waiting to Happen” | The 
New Yorker
<https://www.newyorker.com/news/a-reporter-at-large/the-titan-submersible-was-an-accident-waiting-to-happen?fbclid=IwAR0CN7CyK3Ok72HX4Mf0n6sB6uc95sE-nH5_N1KDrqA5XHU1vx_k8eUCbfo>

Best insider description so far. 

Carsten

-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
Datum: 2023-07-01T12:13:41+0200
Von: "MerlinSub at t-online.de via Personal_Submersibles" 
<personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" 
<personal_submersibles at psubs.org>

I have done the calculation again for a spherical shell sector window with 
conical edge 160Mpa and CF 4.
According to this, a window with 530/376 & 60° would have to be
would have a wall thickness of 161 mm - according to photos it was 140 mm 
at 60° or 110 mm at a 90° fit.
A 90° window would have needed 132 mm thickness according to the code.
Now.. 140 to 161 mm or 110 to 132 mm is not far off - and considering the 
window was inside straight - means there was more material there.
I now think the window was OK from a pressure design point of view. To be 
precise you would need a cross-section drawing with the real geometry.

Carsten

-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
Datum: 2023-06-30T22:29:35+0200
Von: "MerlinSub at t-online.de via Personal_Submersibles" 
<personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" 
<personal_submersibles at psubs.org>

If I use these 120 mm (STCP) and a CF of 4  it was good for around 1000 m. 
With 120 mm thickness it was at collapse deep. 

Carsten

-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
Datum: 2023-06-30T22:18:31+0200
Von: "MerlinSub at t-online.de via Personal_Submersibles" 
<personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" 
<personal_submersibles at psubs.org>

I found a much better picture and correct the figures as follow:

Diameter hull                                   1600 mm (given) 
Diameter front porthole outside         614 mm
Diameter front porthole inside           436 mm 

But given with the outer window diamter given by Jon of just 530 I come to 

Diameter hull                                   1381mm
Diameter front porthole outside         530 mm (given)
Diameter front porthole inside           376 mm 

If I do with the 530 / 376 a little reverse enginering on a conical seat of 
60°
I come to a thickness of just 120 mm for a inside and outside flat  conical 
frustrum window.  

According to PVHO-1-1987  t /Di = 0,348  with  t = 0,348 x 376 mm = 162 mm 
at 40 Mpa (4000m)
(for Short term critical presssure) 

But from Jon's picture it seems more a Sperical Sector Window with Conical 
Edge. and flat inside. 
The code has no figures for such a window. 
But if I use for Sherical Shell windows t/di shall 0,195 means t =  0,195 x 
376 = 73 mm

To be diplomatic I just mix up the flat with the sperhical and got (162 + 
73) / 2 = 117,5 mm  
(for Short term critical presssure) 

The code says if you have not a standard geometrie - you have to test 5 
windows to destroy dephs 
and use the lowest failture pressure for your calculation. 

Carsten

. 

-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
Datum: 2023-06-30T16:11:40+0200
Von: "Antoine Delafargue via Personal_Submersibles" 
<personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" 
<personal_submersibles at psubs.org>

Hello Carsten, 

for the thickness, I read that the viewport should have been rated for 
1300meters depth, so I think that the designer designed for a short term 
critical pressure of 5200m/52MPa, and perhaps thought it would be fine 
using a 1.3X margin to get to 4000m rather than the 4X margin we can find 
in Stachiw book and PVHO rules for low temperatures (to be checked but I 
believe it is 4x). 

regards
Antoine

On Fri, Jun 30, 2023 at 4:03 PM MerlinSub at t-online.de
<mailto:MerlinSub at t-online.de> via Personal_Submersibles <
personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> > 
wrote:
  I check out some pictures and based on a given length of 6500mm
  I come to the following rough figures: 

  Diameter hull                                   1600 mm
  Diameter front porthole outside         700 mm
  Diameter front porthole inside            466 mm 
  (these diameters indicate that the porthole could be original designed as
  entrance..)

  Now idear about the thickness of the acrylic
  - but will check out PHSME about standard flange angles tonight. 

  Carsten

  -----Original-Nachricht-----
  Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
  Datum: 2023-06-30T15:31:14+0200
  Von: "MerlinSub at t-online.de <mailto:MerlinSub at t-online.de> via
  Personal_Submersibles" <personal_submersibles at psubs.org
  <mailto:personal_submersibles at psubs.org> >
  An: "Personal Submersibles General Discussion" <
  personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> 
  >

  For me it looks like the biggest diameter porthole used in that deep. 

  Has somebody here inner and outer diameter and the thickness?

  Carsten

  -----Original-Nachricht-----
  Betreff: Re: [PSUBS-MAILIST] Titan submersible missing at Titanic site
  Datum: 2023-06-29T21:11:55+0200
  Von: "Jon Wallace via Personal_Submersibles" <
  personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> 
  >
  An: "Personal Submersibles General Discussion" <
  personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> 
  >

  The pictures of Titan that I see in water show 16 bolts holding the
  retaining ring in place.  See attached photo.

  Jon

  On Thursday, June 29, 2023 at 11:49:18 AM EDT, MerlinSub at t-online.de
  <mailto:MerlinSub at t-online.de> via Personal_Submersibles <
  personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> 
  > wrote:

  I have seen a video how they make the carbon cylinder and can imagine
  that the boat imploded in longitudinal direction. 
  Create a massive shock wave with push the window out (not in). As I saw
  in another video the window was hold by only 4 bolts outside. 

  All titan parts in the video seems undamaged. 

  Carsten

  _______________________________________________
  Personal_Submersibles mailing list
  Personal_Submersibles at psubs.org <mailto:Personal_Submersibles at psubs.org>
  <http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20230701/a512ae57/attachment.html>