(CNN) Large pieces of the doomed Titan submersible arrive in Canada

(CNN) Large pieces of the doomed Titan submersible arrive in Canada.

See Titan Sub Implosion: The Knowledge Stockton Rush Ignored; Snap-Buckling Failure Mode.

The design was defective in many ways, all of which could cause implosion. One feature can be identified as most  probable, where the titanium end bells joined the carbon fiber tube.

The deep sea is cold. Under temperature change, from surface to depth and back to surface,  the two materials  contracted and then expanded at different rates —  with differing coefficients of expansion.  When, at the factory, the end bells were attached with epoxy cement, all the  parts were at factory ambient temperature. At any other temperature, there was stress between the  parts.

  • Each dive comprised a cycle of thermal and mechanical stress on the epoxy joints.
  • After some number of dives, microscopic cracks began to grow in the joints.
  • Cracks concentrate stress, which is why cracks usually grow.
  • At some cycle, the epoxy failed  in some region of the joint.
  • An area of the cylinder then lost support from the end bell. This area of the cylinder also experienced the most flexure, so it was the most fatigued.
  • Implosion of the cylinder began there, and spread longitudinally in just a few milliseconds.

One might expect that the end bell side of the joint was a flange, with a smaller diameter extending into the carbon fiber tube. Sometimes this is done to achieve a thermal shrink fit, so that the joint is always under compression,  which makes it stronger. This was not done. The end bell began with a flat adapter ring that was simply glued to the end of the tube.

It is possible to join materials with different coefficients of expansion, by use of a slightly elastic gasket, a flange, and constant compression of the joint with tension bands. This was evidently too much bother for Stockton Rush. Even if this were done, it is likely the Titan would have eventually been  claimed by snap buckling.

Which brings us back to safety culture:

(CNN) Missing Titanic sub crew killed after ‘catastrophic implosion’



Titan Sub Implosion: The Knowledge Stockton Rush Ignored; Snap-Buckling Failure Mode

See  A Review on Structural Failure of Composite Pressure Hulls in Deep Sea.


With the increase of the diving depth of the submersibles and the thickness of the composite pressure hull, the structural failure of the pressure hull may change from the overall buckling to gradual material failure. As a result, the design concept of the structure has to be changed. In addition, the large thickness composite pressure hull used in the very deep sea also has its unique failure mode, snap buckling. This problem appeared in the application of deep sea pressure pipelines in the 1980s, and has received more attention and research since then.

For specifics of the Titan design, see Composite submersibles: Under pressure in deep, deep waters. The thickness of the hull was 5 inches.

A little bit of intuition.

  • The metal of a conventional hull has strength in all directions.

  • A carbon fiber / epoxy hull has high strength within the fiber layers, but not between them.

  • The thicker the hull, the more stress between the layers.

Hence, SNAP!

(CNN) Missing Titanic sub crew killed after ‘catastrophic implosion’

(CNN) Missing Titanic sub crew killed after ‘catastrophic implosion’.

Whether you’re at 30,000 feet or minus 13,000, love of extreme adventure is a harsh companion.  Your only defense is  vigilant safety culture.  To turn your back  is to give your companion a chance at your life.

Stockton Rush turned his back. At 13,000 feet, the water pressure is 5600 pounds per square inch, exerted on every inch of the Titan submarine. See:

Boeing, FAA, Space Shuttle Challenger, Richard Feynman, and Safety Culture

Boeing & Safety Culture Redux


Trump Indictment; Is Trump a Flight Risk?

The estimate is that Trump is a flight risk:

  • His personality cannot rationalize imprisonment.

  • He has the means to support himself in any country.

  • His standing in many countries remains high.

  • He has a special relationship with Vladimir Putin.

  • His Boeing 757 has the range to reach Russia’s Kalingrad oblast from anywhere on the east coast of the U.S.

Att: David Zaslav; Future of CNN

This discussion attempts some objective analysis surrounding the departure of Chris Licht. Personalities and friction are omitted. In any case, such factors are not primary to declining market share of CNN. Media markets such as cable news have life cycle phases:

Growth. In this phase, viewers seek new experiences. Novelty, not loyalty, drives the space. An adroit programmer can take advantage of novelty and churn to grow the platform. For CNN, the novelty was the immediacy of always-on news. Multiple competing platforms can grow as they vie for slices of the expanding pie.

Maturity. The game transitions to zero sum. Growth and shrinkage are dominated by churn, with loyalty and novelty in balance.  Now regarded as talent, programmers compete against each other, and execs compete for programmers. This goes way back to Fred Silverman, “the man with the golden gut.”

Decline. In preservation of the factors that drove growth, novelty is banished. Loyalty dominates older age groups, while younger demographics decline. While churn formerly dominated subscriber loss, what happens now doesn’t fit the scenario, as younger viewers abandon the market. Novelty takes a walk. Think Vilfredo Pareto’scirculation of the elites.”

Why this is happening. In the era when broadcast had a lock on mass communication, CNN offered novel immediacy. Broadcast gave way to multicast, replaced in turn by novel peer-peer, otherwise known as social media.  Broadcast formerly provided unbeatable economies of scale; its  impersonal  nature was disguised by the “star power” of uniquely attractive personalities mediated by savvy programmers.

Hence the approach of Chris Licht, which in the main was the shuffling of personalities and combinations through time slots. This is the purest form of network programming. The effect on CNN has been strongly negative, intimately related to the transition of cable news to the phase of decline:

  • Demand for novelty is absent.
  • Retention is based on loyalty.
  • Loyalty abhors change.
  • In consequence, any change Licht could or did make resulted in viewer loss. The transition from maturity to decline is a programming  “game changer.” It rendered Licht’s  prior experience useless.

Political slant  has,  in comparison, minuscule effect. If the above reasoning were not operative, there would be enough liberals to  sustain CNN.

Is there a future of long-term viability? Fox shows that political hysterics work, but this immoral option is not available to CNN, which is a morally grounded enterprise. If there is a long-term future for CNN, it is to be found in new approaches to:

  • Immediacy, allowing some bypass of format considerations that were relevant in the broadcast era.
  • Enrichment of Information flow.
  • New approaches to controversy.
  • Connection with viewers, which can be mediated by AI.

I would like to play a part in fashioning a viable future for an organization with a strong moral compass.