quote:

Originally posted by Stlhead:
I think mermaids or aliens or some other absurdity at the bottom of the sea would be more fun to debate than the construction details of a squished sub. Even if folks here build carbon fiber subs as a job or even hobby the level of commitment to the carbon fiber is good or carbon fiber is bad argument seems a bit much. I also just don’t feel like this entire issue was worth more than a passing mention and a few minutes in the news cycle but it seems to have been the top news item for 3 days.

I had not intended to post more in the thread, but Para asked for a clarification.

quote:

Originally posted by a1abdj:
Would the same place that tested Alvin's titanium sphere be a suitable authority for testing carbon fiber tubes as it relates to deep sea submersibles?

https://www.usna.edu/NewsCente...OTF_Brochure_003.pdf

quote:

But maybe a1abdj you could tell us how many times this carbon fiber marvel of undersea exploration was tested at depth, returned to the surface, and tested again, and again

quote:

Originally posted by 229DAK:
From WTOPnews in Washington DC:

A day after revelations that the Titan submersible imploded, officials searched the ocean floor for evidence and grappled Friday with vexing questions about who is responsible for investigating the international disaster.

It was not entirely clear Friday who would have the authority to lead what is sure to be a complex investigation involving several countries. OceanGate Expeditions, the company that owned and operated the Titan, is based in the U.S. but the submersible was registered in the Bahamas. OceanGate is based in Everett, Washington, but closed when the Titan was found. Meanwhile, the Titan’s mother ship, the Polar Prince, was from Canada, and the people on board the submersible were from England, Pakistan, France, and the U.S.

quote:

The Transportation Safety Board of Canada said Saturday that it’s conducting an investigation into the loss of the Titan submersible and has been speaking with those who traveled on Titan’s mothership, the Polar Prince.

The development comes as authorities from the U.S. and Canada began the process of probing the cause of the underwater implosion and grappled with questions of who was responsible for determining how the tragedy unfolded.

Maritime agencies are searching the area in the North Atlantic where the vessel was destroyed, killing all five people aboard. Debris was located about 12,500 feet (3,810 meters) underwater, several hundred feet away from the Titanic wreckage it was on its way to explore.

“We are conducting a safety investigation in Canada given that this was a Canadian-flagged vessel that departed a Canadian port and was involved in this occurrence, albeit in international waters,” said Kathy Fox, chair of the transportation board. “Other agencies may choose to conduct investigations and that’s up to them.”

The Polar Prince left Newfoundland on June 16, towing the ill-fated Titan. There were 41 people on board — 17 crew members and 24 others — including the five who died when Titan imploded.

Fox said she understands the international interest and that the TSB will share information they collect with other agencies, like the U.S. National Transportation Safety Board and the U.S. Coast Guard, within the limits of Canadian law. Voice recordings and witness statements are protected under Canadian law, she said.

“Our investigation will go where the evidence leads us,” she added. “We don’t want to duplicate efforts. We want to collaborate.”

The Royal Canadian Mounted Police also announced Saturday that they’ve initiated an examination of the circumstances that led to the Titan deaths to decide whether a full investigation is warranted. That full probe will only take place if it appears criminal, federal or provincial law may have been broken, officials said.

quote:

Originally posted by a1abdj:

quote:

But maybe a1abdj you could tell us how many times this carbon fiber marvel of undersea exploration was tested at depth, returned to the surface, and tested again, and again

How many times was the first titanium sphere version tested at depth? How many times was the steel version tested? What about the ceramic version?

The answer is that EVERY new concept has its first, then second, then third. It's great to say "well the titanium has proven reliable 1,000 times", but it had to start at number 1. You don't know what you don't know, and you often only find out by doing it in many cases.

What I find most interesting about this discussion (if you want to call it that) is that there are likely three very possible points of failure. The carbon fiber could be the culprit, the bond between the two dissimilar materials could have failed, or the view port could have failed.

All three of those points were engineered and certified, but only one of those was certified at a number well below that required, and that's the viewport. Statistically speaking, that's probably what I would be looking at first, if there's even anything there to see.

If I was rigging a 20 ton vault door on a 40 ton crane with a 40 ton winch and a 5 ton cable and it broke, I wouldn't start by looking at the crane or the winch.

quote:

Originally posted by nhracecraft:
You ought to test it as well...It seems they went straight from the design concept, to production, to 'sea trials', and ultimately to the sea floor!

quote:

Originally posted by a1abdj:
If I was rigging a 20 ton vault door on a 40 ton crane with a 40 ton winch and a 5 ton cable and it broke, I wouldn't start by looking at the crane or the winch.

quote:

60+ years ago the first titanium bell was probably WAY over-designed for the pressure based on hand calculations by engineers. The strength and fatigue properties of Titanium alloys, and steel alloys (and aluminum for aircraft) are well known. As we have learned more over the decades and now have FEA and other tools at our disposal, with metal alloys that can be made more precisely and more uniform, the designs can be optimized. Remember the SR-71 which used a lot of titanium was designed on paper by men with slide rules - no computers. And there have been no catastrophic failures of these planes (at least none reported).

You keep arguing in favor of how things were done 60-100 years ago during the learning process rather than how they are done TODAY, with decades of real world experience, much better understanding of materials, and advanced 3D modeling, FEA, Thermal analysis, etc.

quote:

Regardless of the exact failure mode, this asshole ignored a lot of knowledge, went his own way, didn't test it adequately, didn't inspect it adequately after each use, and got himself and the others killed. He failed to follow basic engineering design, validation, manufacturing, testing, and monitoring/inspection disciplines. And at this point in history, such behavior is absolutely inexcusable.

quote:

Yeah, would you put humans under the vault door before the you knew how the cable performed? Would you test the cable multiple times? Idiotic analogy. You're sticking up for this woke fuck

quote:

I'm not sure why.

quote:

All three of those points were engineered and certified

quote:

Originally posted by a1abdj:
I'm not defending Rush in any way. I'm defending the opportunity to learn from failure when it comes to new technologies. I'm generally against the banning (or over regulation) of things simply because it makes people feel weird.

quote:

Other than Rush, certified by whom? He appeared to have dodged any legitimate certification process.

quote:

Ph.D. Engineering Mechanics – University of Nebraska, Lincoln, Nebraska, 1988
M.E. Mechanical Engineering – University of California, Davis, California, 1981
M.E. Industrial Engineering – University of California, Berkeley, California, 1971
B.S. Agricultural Engineering – University of Nebraska, Lincoln, Nebraska, 1970
Registered Professional Engineer – Nebraska and California

quote:

The design of the Cyclops 2 hull, says Spencer, is based in large part on the strategy applied to Fossett’s DeepFlight Challenger. Thickness, he says, was estimated using micromechanics, and then verified with finite element analysis (FEA). Modeling was done in SolidWorks (Dassault Systèmes, Waltham, MA, US) and analysis was done with COSMOS/M, supplied by Dassault Systèmes subsidiary Structural Research and Analysis Corp. (Santa Monica, CA, US).

quote:

Using the finite element software code COSMOS/M orignially developed by Structural Research and Analysis Corp. (Santa Monica, Calif.) but now licensed by Dassault Systèmes SOLIDWORKS (Concord, Mass.), Spencer developed and optimized a laminate that uses only hoop and axial plies, in a ratio of about two hoops for every axial, using a repeated sequence that reduces strain variation through the laminate wall. “To reduce the strain variation and allow a higher overall applied load, we varied the hoop modulus through the wall thickness,” he explains. “The inner laminate has higher hoop stiffness than the outer laminate.” To ensure that the capsule would withstand full ocean pressure, the hoop compressive strain capability was targeted at 0.45 percent.

Spencer built a number of half-scale tubes to test several designs, including different hoop-to-axial fiber ratios, variations of fiber type and fibers of different moduli in the laminate. Tests were conducted at Pennsylvania State University’s (State College, Pa.) test laboratory, one of a handful in the U.S. able to generate the necessary compressive stress loads. Results were compared to the finite element model and anticipated failure modes. Spencer reports that the subscale samples withstood a maximum fiber compressive stress of more than 125 ksi/1,250 MPa and exhibited compressive strain capability that exceeded 0.48 percent.

The full-scale capsule was fabricated using a Spencer Composites-designed 4-axis CNC machine adapted for filament winding. The machine layed down a 2-inch/50-mm wide band of carbon fiber supplied by Grafil Inc. (Sacramento, Calif.). The toughened epoxy resin matrix was custom formulated by Spencer. The resulting oven-cured laminate, 5.15 inches/130 mm thick, has a fiber volume of 67 percent and “essentially zero voids,” claims the company.

quote:

The opportunity to learn typically involves testing the device before you put a human in it. Not it this case.

quote:

Originally posted by a1abdj:


It was tested prior to putting humans inside. I've pointed this out several times. You guys should really take the time to look into some of these things before making factually false claims.

quote:

Originally posted by a1abdj:

quote:

The opportunity to learn typically involves testing the device before you put a human in it. Not it this case.

It was tested prior to putting humans inside. I've pointed this out several times. You guys should really take the time to look into some of these things before making factually false claims. Perhaps you guys are mistaking being accurate and factual with defending Rush. Two different things.