Posted On: Thursday - June 29th 2023 2:31PM MST
In Topics:   Political Correctness  The Future  Science  Muh Generation
I was very surprised to learn recently that the title of the well-known Jules Verne novel 20,000 Leagues Under the Sea was bogus. I only recently looked it up, to find out that the Olde English unit unit of length - the "league" - was 3 nautical miles for sea purposes (and 3 statute on land). That'd put the location of the story in the novel way out in space on the other side. I guess it just sounded cool. The now destroyed (and being recovered) Titan deep-water submersible was down at just about 2 nautical miles. (1 nm ≈ 6,000 ft., 6,076 to be more precise.) The pressure down there is 5,350 psi.
Because water is nearly incompressible, pressure varies almost linearly with depth, very unlike the pressure variation within the atmosphere, made of gases, for example. The factor is about one atmosphere (~14.7 psi)* for every 33 ft down. So that was easy. That's a LOT of pressure. Diving down to 400 ft is a big deal and must be done carefully, so 2 leagues under the sea is an not anything like a proper environment for a human being.
The Titan story is interesting infotainment, and there a few aspects being discussed. Regarding one of them, I have no problem with whatever toys any grown-up boys want to play with next. Dangerous or not, it's always great for the world to have guys out there exploring and learning new things. Too bad, per Dieter Kief, this project used some of that "CARES Act" money. I don't like that aspect, no siree.
When it comes to the political aspect of the story of the failure of the Titan deep sub, I don't know any more than anyone else. I refer the reader to Race Realist blogger Paul Kersey. The excerpts from the Lyin' Press (usually) are normally the bulk of his posts, and he adds commentary and sometimes a few extra details on stories that hit close to home. That's the case again in CEO of Doomed Submarine Going to Titanic Didn't Want to Hire '50-Year-Old White Guys' Because They're Not 'Inspirational', as it appears on The Unz Review.**
Peak Stupidity has noted a something in our many posts on the Big Biz world. The HR ladies** and the big cheeses are, if not the very founders of it, big proponents of the anti-White-man D.I.E. program***. The designers/builders of the Titan worked within a medium/small sized company called OceanGate. The outfit has (or had, to be both accurate and maybe a bit morbid) 47 employees, a very convenient number when it comes to keeping out from under the massive Feral Gov't regulatory beast****. Lots of regs start applying at the 50 employee level.
The founder of OceanGate (in '09), Stockton Rush, was one of the 5 explorers on board. (Yeah, it was an all male thing. Did anyone have any problem with that?) The D.I.E./Woke aspect here is the attitude of this 61 y/o White man, as he mouthed the usual diversity platitudes. I believe that was nothing more than a corporate jargon reflex. These people love the corporate "24/7", "Core Competencies", "bandwidth", and "low hanging fruit" jargon.***** The diversity platitudes are expected, though, when taken seriously, they can mean trouble. Was that the case with the Titan?
The Titan was basically a cylindrical pressure vessel. For the life of me, I find searching for simple stuff like the P.V. dimensions harder and harder, but I got the wall thickness of 5" and am guessing from "height" of 9' that the P.V. diameter was something like 6', scaling from the pictures. This makes it a "thick-walled" pressure vessel, defined by engineers as one with a thickness < 1/10 of the radius. (Well, which radius, inside or outside? If that difference is significant to you, then, guess what, it's not a thin-walled pressure vessel. Haha!)
Now, this is engineering. Engineers make approximations to make things easier. This was especially important before fast ubiquitous computers, and we'll get more into that, but even now, as the idea is to keep the theory under control, i.e. theory that has already been worked out accurately. The difference between what's defined as thin-walled vs. thick-walled is in the former, the stresses within the material don't vary much across the radial dimension, so can be considered constant. (For the other 2 dimensions, the axial, and the tangential - using polar coordinates, of course - there is nothing to make them vary in either type P.V. so long as it's a cylinder, or sphere for that matter.) Why the dividing line right at 1:10? That's close enough for engineers to a situation in which that stress is fairly constant and easy to calculate.
The barely calculus-based derivation of the longitudinal stress in a thin-walled P.V. come from a force balance between this constant stress acting on a cross-section of wall and the pressure as applied to the area on the end caps. (No, the shape of the ends doesn't matter at all for this.) Take a slice perpendicular to the z-axis (length) and you get σ A x-section= P Ainternal. That's σ 2π r t = P πr2, which simplifies nicely to σ = Pr/2t.
For the tangential stress we do something similar. Take a cross section the long way. The forces acting from the stress on the 2 areas, one on top and one on the bottom, therefore, 2 L t, must equal the force from the pressure acting on that x-sections area, but only the projection of that area (note that if we're summing forces horizontally, pressure forces near the top, for example, would have very small components in the direction we are summing.) Don't worry, it all works out! A diagram would be extremely helpful, but I can't do that right now. So, σ 2 L t = P L D, or σ = Pr/t. That's often called the "hoop stress" and it's double the longitudinal stress.
Those stresses combine to get a value that can be compared to the inherent strength of the material. Again, the Titan was NOT a thin-walled PV, but to just get an idea of the magnitude, the shear stress that would result from those 2 normal stresses (in the thin-walled P.V. theory) would end up equal to the larger of those 2 - please don't ask - I LUV LUV LUV Mohr's Circle, but I'm tryin' to finish a blog post here, y'all, and I'm not getting paid. There's no way to pay me, if you tried. Anyway, that max. shear stress would be in the range of 40 ksi. (That's ksi, a bastard of a unit, meaning kilo pounds/square inch.) 40 ksi is up there with the yield strength of some regular materials, but not near that of specialized aerospace stuff. The Titan was made with carbon fibers within an epoxy matrix of material.
Why'd I do all the calculations? Admittedly, that was partly for fun, is the answer, but also to give the idea that this was serious business. Let's do more thinking. For a thin-walled P.V., the simple theory to get stresses was based on INTERNAL pressure, but with the signs reversed, we get the same numbers with compressive stresses resulting. As you've probably read regarding this Titan deal, and may know elsewhere regarding concrete, some materials have different strengths under compressive stresses vs under tensile ones. How well was this all known for this complicated non-isotropic material (different strengths in different directions of stress)?
Compressive loading has a failure mode that is not a factor with tension. That would be buckling or crippling. To start off simply, let's discuss briefly 2-D, with buckling in columns. It's basically 2 2-D problems, unless the thing is axisymmetric, aka, a round column. The difference in this mode of failure is that the inherent strength of the material is not a factor, but the geometry and the stiffness (the x-sectional shape and the material's "modulus of elasticity" - a material property, the latter being one number for an isotropic material but NOT for these composites) are.
This is easy to envision. You've got a 1" diameter piece of steel/iron plumbing pipe. You weld 2 1' square pieces to each end, one for the floor and one to stand on. Make it a one foot length of pipe. Unless is this some cheap 1 mm wall, China-made crap (see 2 paragraphs down), well, it'll hold you. Say, you're 200 lb, and let's say it's only 1/16" wall. We get a x-sectional area of 2πr t, so, for simple axial loading, σ = F/A = 200 lb/(0.062in)2π(0.5in) = 1000 psi = 1.0 ksi = peanuts.
Now, do the same with a 100 foot length. (Call the PS accounting office to ask about hazard pay, first. It's hard to collect later.) What's gonna happen? Buckling, that's what. The stress in the material is the same, as length doesn't appear in that calculation we just did. No, but this failure mode is one of instability. The slightest off-center application of the force - your ass 100' up there! - results in a bending loading that results in more deflection, resulting in more bending loading, in an unstable fashion. Now, you're back on the ground, perhaps injured, but consider yourself better off than Stockton Rush is.
With a hollow cylinder, we have a 3-D and much more complicated mode of failure due to instability called crippling. Envisioning this is easy too. Stand on an empty Coke can sometime. Then get a friend - or if you're pretty agile, you can do it yourself - to lightly kick the side of said can. There you go, down to Earth, and little Greta thanks you for recycling ahead of time. This already difficult theory, the crippling mode, is made all made more complicated when it's done on this composite material. BTW, that Coke can is a seriously-thin walled P.V. Thickness is about 4 thousandths of an inch. With a diameter of 2.6", that's a t/r of 0.003.
Now, finally, regarding the engineering work that must have been done, you've likely read about the fatigue effect too. Yet again, for simple homogenous, isotropic metals, work in this field has been done for most of a century******. It's not just pressure vessels such as airplane hulls that undergo fatigue. Think of any rotating part. The simplest would be motor shaft with a pulley with a belt around it. The tensions on both sides of the belt go in roughly one direction, causing stress in the round shaft. So? Yeah, but this loading direction is fixed in space while the shaft rotates. The stresses are applied back and forth (up and down in value) every rotation. At 1,800 rpm, you get a lot of cycles in a hurry! Then, for these metals, the empirical data used is made for numbers like millions to billions of cycles. Airplane hulls must be light, hence they get made to withstand cycles in the range of 10's or 100's of thousands.
What about that sub? I don't know. It wasn't going to undergo thousands of cycles, but again, things get more complicated with new materials. (Also, compressive loading on a thick-walled P.V. is different from that in the composite lay-up aircraft hulls which are thin-walled and undergo internal pressure.)
Now, your PS blogger here is not going on and on with this engineering talk just for his health. Then too, I don't claim to know enough to make any comment on the failure of the engineering work either. (I guess, with the sub having been pulled up, OceanGate and we will find out at some point.) I do have a point though. This goes back to the comment on the 50-y/o White men and the disparagement of the hiring of them. Did Affirmative-Action-Adjacent engineering have something to do with this? It's likely not, because, as I wrote above, all that talk was just a reflexive platitude out of Stockton Rush. I think the problem is not about the engineering not being done by 50 y/o White men in the future, but about it not being done the 50 y/o White of today, in the future.
Let me explain. It's not just about the age and race, but about the times. It's about there being more and more reliance on software tools than on very basic deep understanding, by engineers. Yes, one could call this part of the decline in competence that has been one of our themes lately.
OK, just to go back into it a tad, when the math in the theory gets unsolvable in closed form, then we resort to software, since we can now. That's not a bad thing. Finite Element (and Finite Difference) analysis for stress/strain and for heat transfer has been around for half a century. Yet, many problems were too big, and engineers had to make proper assumptions, find empirical methods, and/or get more into the theory. Engineers had to be creative. I mean, the only other way to run a big model was to get more of those Hidden Figures gals to do billions of calculations, yeah, just get 'em, by the 100's of thousands, working there in the nursing home. What's a couple of hundred tonnes of creamed corn in comparison to a new Cray mainframe?
OK, anyway, the computers are so fast now, that, other than in the fields of turbulent gas dynamics and such, there is confidence that anything that can be properly set up as a model can be analyzed, with accurate results. Is there too much confidence, and are the underlying assumptions that the software is written around different sometimes? Was that the case with the new material used in the Titan?
Under the Global Climate Stupidity topic key, Peak Stupidity discussed 6 years ago the problems with the reliance on mathematical models of the entire climate of the Earth. We don't have a problem with the effort to do this. We just have a problem with those who have this false confidence that this complicated of a task (with still unknown processes involved and complicated interactions) has resulted in anything like an accurate working model.
This overconfidence in "the software" is more of a problem with the younger generations. They don't want to look at the calculus and the experimental results graphs. Instead, they want to get as many pieces of software as possible and plug lots of shit in. I think this overconfidence and over-reliance is a likely cause of the Titan disaster.
What that means is we need not only 50 y/o and older White men doing this serious work, but we need the 50 y/o White men of today, who got their engineering/tech knowledge 30 years back. 50 y/o White men doing this 10 or 20 years from now may not cut it. Going woke in addition? Well that'll just bring things to a point where they'll have to send convicts down in the subs, as nobody will want a part of that. That's if anyone would know how to do a project like this in what's left of America in 2050.
* Sorry to the Euros and, well everyone non-middle-aged and older American, but we'll stick to English units in this post.
** I see that Mr. Kersey has been keeping his titles shorter lately. Yes, this one IS shorter. ;-}
*** OK, here we go ... HR is the scourge of the Big Biz world!: Part 1 - - Part 2 and Part 3.
**** The Big Gov readers here, and you know who you are (the one guy?) may see that as having been a factor in the disaster in the deep. Nah, we're talking government. Would anyone in Woke/AA Government know more than these guys?
***** Yeah, it's been so long, I had to look a couple up. Once and former cube dwellers may enjoy this page on a site called Wavelength.
****** In fact, one big impetus for fatigue analysis and crack growth study was the demise of a few of the de Havilland Comets, the first operational commercial jetliners (by 6 years), that were mentioned briefly in our recent post 1st World Memories of Suid Afrikaanse Lugdiens (CtDC - Part 7). Cracks started at square window corners (normal windows were square, so...) and the repeated pressurization cycles caused crack growth - it's called "metal fatigue". There was more to the demise of that airliner than that - there were also some hard landing due to the differences in operating a new type of airplane like this.
[UPDATED 2 hrs. later:] Per Dieter Kief, this project did use some taxpayer money. Fixed.
[UPDATED 06/30:] Geeze! Math error right in the title! I was thinking 1 league = 1 nm when I first did this. That was the easy part.
[UPDATED 06/30:] Not "titanium matrix" around the carbon fibers but epoxy, as is the norm. I had a hard time imagining a metal matrix, but I figured I haven't kept up, and I shouldn't get ANYTHING off non-technical articles. (Fixed after watching the "Sub Brief" guy in the video provided by commenter Adam Smith.) What were made of titanium were the 2 end fittings. They were epoxied on to the standard carbon fiber wrap.