The latest submarines may increasingly feature a new angular outer hull. For example the German Ttpe-212CD. This has to do with stealth. Let me try to briefly explain... Info on the Type-212CD www.navalnews.com/naval-news/...
Very good explanation: A few more factors I would add to this discussion are 1) Effective Target size (aspect) 2) bottom type (hardness) 3) sea state all play a factor in active effectiveness as well. My opinion is that this new design will significantly reduce Active Target visibility in all environments when compared to similar conventional submarine examples.
I presume this is the same idea you referred to recently when discussing the Astute's bow? If that was the goal I wonder why Astute and Trafalgar didn't continue the bow chine all the way down their sides. Difficulty mounting the flank array maybe?
@@SonB288 Couple of things strike me on this question, the chine does end exactly where the flank arrays begin, that may have been a compromise where they focused on frontal aspect stealth for approaching a target. Second the torpedo tubes in the Astute are right at the side edge, there isnt any internal space given over to outer hull shaping beyond the pressure hull. Finally the Chine is exactly the same location as the floor of the upper deck, it might be a reinforcement strut to redistribute some of the squeezing away from that particular location (and the same location the forward superstructure) and add increased structural strength.
One thing I'd like to point out and what i don't know if you deliberately omitted or missed: the HMS Astute appears to exhibit this very same feature, by about 20yrs. In addition, like astute, subs with this angled feature have a tendency as Astute, to have a slower design speed; because of the hydrodynamics of a angled hull over a teardrop design. Just speculation btw, not a professional.
Another thing to add: the German 212 submarines use Hydrogen fuel cells and batteries. So they basically don't have any moving parts except for the propeller itself. They have reached a point where you can't do much to reduce engine noise anymore for passive sonar stealth. So active sonar was the only remaining weakness, the only thing you could tackle and get better at. Also interesting, the German submarines are usually small because they must be fully operational in just 17m deep Baltic waters.
As far as I know: anechoic tiles were first (to my knowledge) used in Germany during WW 2. Called "Alberich" after a dwarven king in german mythology, it was developed in 1931 and applied to multiple submarines in 1941 🙂
@@labschi No, they had problem with the glue, the tiles started to fall off. I believe that they finally fixed that in late -44 but then it was too late and the Anglo menace triumphed;)
I mean everything from 1920 to 1970 can be summarized by "we had the best German scientists and engineers". Nuclear weapons were developed by a lot of German scientists in exile in the US. The space race? The German V2 rocket engineers picked up by the US vs. the German V2 rocket engineers picked up by the USSR.
I believe that is something that can actually be done through the use of active pings from torpedoes. Calculations might be a bit more tricky, but the pings won’t be coming directly from your ship.
actually I came here to raise the same question, some sonars have a remote emitter. And for airspace some systems use the reflections from telecom emitters to spy without emitting themselve.
I think it's a lot more common to have nuclear powered listening station which can permanently listen to an area rather than a drone which has a temporary lifespan. But on the attack into enemy waters remote sonar station drones make a lot of sense.
You can use existing biological noise as the source for a semi-active sonar in which you look for shadows using passive sonar and the more angles you can use to look at the target you will be able to better develop your target location depth and speed..
Great video, as always! Really interesting how technological developments can force a continuous cycle of one technology over the other, being replaced by each other in a loop. That is ongoing until a major breakthrough happens, or a major technological leap is achieved.
I think the sharp angles in the early stealth plain have more to do with the difficulty to calculate the radar reflection rather than that they are particular good for that. Newer stealth air crafts are more curved.
@@MusikCassette i guess he meant 8:38 there is the thing with the thermocline layer (the layer between the warm surface water and the cold deep water) and different layers of seawater too, as sound waves can be diffracted between the surface and the thermocline, or be reflected from the thermocline back to the depth
Great video, just one detail: Norway isn't just a customer, it's a joint development and meant to be the beginning of a strategic cooperation in Research & Development of AIP submarines, a German-Norwegian Research facility has been established at TKMS, and both German and Norwegian units will receive maintenance at a Norwegian central facility. The Netherlands have been offered to become somewhat of a third participant in this strategic cooperation if they should decide on the slightly modified Type 212 C/D-E for their new submarines.
That’s really important to know, I wouldn’t have learned that if you didn’t take the time to post that so thank you very much. Idk why we don’t have news that tells us these things in the USA . No real news , just nonsense on the news here 😂
@@MattttG3 I watched a lot of American news when Trump became president, daily for 1-2 years and as far as cable news is concerned, I'd have to agree. It's 95% domestic, rather petty, and depending on whether you watch Fox or MSNBC, you get everything served with a lot of spin. 🇩🇪 news is more like CBS. News at eight have no commentary at all. News at ten have become more opinionated in the last ten years. Btw, since this seems to interested you: 🇩🇪 and 🇳🇴 signed a general treaty for strategic cooperation in Defense Matters. May seem silly since Norway's rather small, but the whole German Defense Sector ain't that big either. Rheinmetall builds the Lynx, Panther, Boxer. TKMS builds frigates and corvettes, usually with two much recon equipment, good motors and not nearly enough armaments, KMW was grandfathered in as important because they build the Leopard 2. And Diehl build Air Defense, like recently the Iris-T SLM for Ukraine. And that's about it. Maybe 75,000 employees altogether.
Few people realise that weapons designers have “fashion fads”, this is related to sales, I.e. what they can sell and “demand” what the higher ups (superior officers and politicians) want. THEN, there is the corruption factor, both overt corruption I.e. some one gets money to make a decision or covert I.e. some one or some group gets a benefit (free holidays, women, political donations, relatives jobs etc).
Very good Hutton, previous works by the germans paved the way for today . The example are the models XXI and XXIII and my favorite the Horten 229 jet the first with the available materials of that time.
Autonomous underwater vehicles and underwater drones could bring new age of active heavy environment to naval battlefield, painting targets to silent killers that lurk elsewhere. These sonar cross section reducing designs might suit very well there.
Some other factors that make stealth on submerged vehicles quite different from the challenge of stealth with aircraft. For example, longer wave lengths, spherical spreading, cylindrical spreading, SVP and convergence zones, etc.
The algorithms used for the shape design are typically evolutionary algorithms or genetic algorithms, which are not AI in how the wod is tday used but rather a well-established soft computing practice. They are useful for optimising any computational impossible problem whose outcome can be measured for fitness and who accepts a finite set of input variables.
An angular outer casing would be easier to fabricate and the tiles would likely stay on better. When you see a boat return to dry dock for maintenance there are always numerous tiles missing.
The Navies around the world are finally waking up. In the book "Skunkworks" by Ben Rich it said they did make a quick model and gave it a try. It had a sonar reflection (IIRC) 1/100th that of a normal sub. The USN response was "Submarines are round".
@@hint0122 real question from a plane nerd: why would that matter? If the ship is sufficiently hard to detect, then it can simply sit at shallower depths without caring, right?
@@IntrusiveThot420 There may have been issues when it comes to the body creating hydrodynamic noise. basically the fear was likely that the body would induce turbulent flow in the surrounding air, making noise that can be picked up on passive arrays.
I figured out a "Stealth" design over twenty years ago, but the problem is the extra turbulence created by the angular hull. You can still detect it with passive sonar.
Yes, agreed! Hydrodynamics would definitely play a big part insofar as operating envelope/efficiency, too. Clearly, screws would be OUT in favor of specially shrouded propulsors (or even magneto hydrodynamic propulsion...the "caterpillar"). Also, I would imagine a stealth boat would have to be exceptionally well-trimmed to avoid deployment and use of control plane surfaces (e.g. retractable bow planes). I am not convinced this will be viable with large boats (modern nukes, etc.).
Just had an interesting thought: If the stealth sheath over the hull had an embedded material in it angled to reflect sonar, you could go back to having a smoother, less turbulent exterior shape by relying on the angles of the embedded material to reflect sonar rather than the physical shape of a homogeneous material.
As I understand it, stealth jets already do this. They have angled ‘echo chambers’ inside the jet to increase radar deflection. This is one reason why the F35 is much more aerodynamic than the old F111. No doubt, weapons designers will have thought of things long before you and I will.
That's the principle of metamaterials. But the challenge is always matching the acoustic impedance of the metamaterial to the impedance of the water, because it is at impedance changes that reflections form. If you can get the wave into your metamaterial then you could acoustically "cloak" your submarine by guiding the sound around it. But that is a LOT easier said than done.
@@jeffcauhape6880 No idea, I do EM. The physics of wave propagation are very similar between acoustics and EM but I don't know much about acoustic material properties. I think it is mostly a property of temperature but dont take my word for it.
One of the big problems with this, and the angled hull, is hydrodynamics. They are similar to aerodynamics, but by no means the same. friction and vortices created by "rough" surfaces or edges might cause sound that is even MORE telling than the sub itself. Kind of why the F-35 is not invisible in rain. The "splatter" can be seen by sensors and infer where the plane is, even when the plane itself does not show. Some thing if a sub is too angled. The edges will cause the water to stir in different ways, that might be picked up easier than from a drop-formed sub.
You should do one on the rubber coating. First developed by the Germans in WWII. Two layers, one with a specific pattern of holes with the signal absorbed by the 2d layer.
that was interesting-- what about textured hulls, because if you had uneven or cobbled surface it might scramble the pursuant sonar. When an angled hull bounces the incoming sonar, it deflects the sonar to a different position like a billiard ball hitting two or three points, so misdirects the sonar reading. That could be very useful ploy, something akin to the idea behind Dazzle paint schemes.
One issue would be increased drag, another would be with scattering, you don't actually have 0 bounces back, instead you'll reduce the chance of a single return. You'd probably see increased echoes from all the bounces striking the sea bed and waves. Whilst reduced it's still sending out a large signal.
Just a note to say that the classic angular shape of the F-117 was almost entirely down to 1970/80 computing power. The next stealth aircraft, the B-2, was far less angular and the modern F-35 not angular at all. My point is simply that blocky angles does not necessarily equal stealth.
2:45 "active sonar lets you be heard farther away, typically twice as far." I don't think so--not a naval engineer, but still an engineer. If the target reflected the signal perfectly back as a flat mirror, you would hear it at twice the distance but in fact no target does that. Typical targets will reflect less than 100% of the sound, and reflect it with more dispersal than it came in with, causing reflections to be far weaker. I'm just reasoning from first principles here, but I know aircraft radar can be spotted at 250km despite only seeing targets within 50km. Another thought experiment: at night on a moor, how far away could you see someone with a flashlight? several km if the ground is flat enough, no? Would he be able to see you at half that range? Yes... if you were a mirror. But even if you were dressed in white, so little of his light would reach you over a km that he probably wouldn't see the return light since a white object would scatter light in all directions not just back to the man with the flashlight.
I think H I Stutton meant the ship sending out the blip can be heard twice as far away than what they themselves can hear an eco back. Ie, the silent sub can hear the approaching ship long before the ship can hear the eco from the sub.
@@Br1cht > You´re arguing with known axioms that been researched and understood for a very long time I´m afraid. If so then please cite a source I can refer to that the range to detect an active sonar emitter is only twice its detection range. To be clear I'm not arguing the general shape of the premise, only that the 2x here is likely to be more more like 5x (as it is in aircraft radar as I explained) or higher.
Curious to know what is between the outer stealth hull and the inner pressure hull. Whatever is in that space is going to dramatically affect performance either adding ballast or buoyancy and of course test depth and crush depth would also be affected. I'm fairly sure the depth performance will be "classified" but an educated guess perhaps?
You might also add the British Astute class to the list, at least because of the bow section, aft to around where the foreplanes are located, which is noticeably more angular than the hull continuing aft of the foreplanes. Something else that occurs to me is that the future use of UUVs, deployed from larger boats, will permit a "stand-off" active sonar capability, where a relatively expendable asset, at a distance from the mother craft, "goes loud", paints the target, and transmits the data to the attack boat, which can then put in an attack, hopefully leaving it much less vulnerable. At least until torpedo launches are detected.
Keep sending your fantastic videos out ! Like most of your subscribers, I don't listen to or view your content in judgment of how great your reporting skills are because I'm here due to the pure quality of your message? So, keep posting and we will keep watching, listening to and giving you thumbs up of course 👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼🙂
I like the unscripted style of video. Most of my favorite sites are definitely of the unscripted type. I think that the unscripted style videos, aside from the "organic" aspects, are that they show more technical knowledge on the part of the video creator.
Do you think that there may also be a need to specialize depending on the projected target environment. Types of sonar used, water makeup, sea floor makeup and depth of water and layers. Your target shore or harbor may not have the same physical makeup of the testing range.
Nice video. Question: these shaped hulls reduce the capacity of going deeper? Also, what's the sonar range? Can a submarine avoid detection by doing deeper? Thank you in advance!!
However. In regards to dispersing the incoming sound in "other directions", will have a big issue of its own. One isn't particularly hidden when wearing all black in a gray room. Nor all white for that matter. Sonar can hear the eco of the sea bed itself, it there is a spot where it clearly is missing, and said spot shows clear signs of parallax error as one moves, then there is clearly something there at a now known depth and position that disperses the expected eco from the sea bed itself. (to actually know the depth and location of the anomaly, we have to have more than 1 sonar, as to get some stereoscopic view of the scene. But on a 100+ meter ship, that shouldn't be all that hard.) So it is a fine balance. Perhaps subs could use phased array piezoelectric transducers covering their exterior, as to both notice the incoming signal (and "perfectly" cancel it out), and mimic a returned eco with appropriate delay for where the sea bed is known to be. But this would be fairly complex system to say the least...
Would a signal from a vessel using active sonar, during its journey reduce to half when travelling to a target then back again, or one quarter (inverse square law)?
It's not actually artificial intelligence that has enabled these designs, it is computers with more computing power to handle the millions and billions of calculations necessary in a reasonable amount of time to simulate the behavior of sound waves in various densities of water reflecting off of of very complex shapes.
Interesting, Le like consistent comment on both range and crew endurabiity. For example, does the 212cd have different handling problems, is it a rougher ride for the crew, does it cause more crew fatigue, does it affect range (I think it would dramatically affect range, but I don’t know).
That kind of information probably won't be available until stealth submarines have been in service for decades and we get books written by crew or whatever
In theory, you could simulate this with an RTX. Just simulate the parts of the sonar pulse that should reach it in 2 bounces, and then simulate the pulse as a bunch of rays eminating from one source. Set the water, the thermal layer, and the surface to be reflective layers to the degree that they are, and you get a good approximation (at least from my understanding of this topic)
bro that's super clever. might not be the most accurate way. but would be a very affordable way to rough and sketch things out. And probably still reach functional designs.
@@ALegitimateRU-vidr Yeah, though you'd need to run a more detailed analysis to make sure probably, but rapid prototyping is kind of a big deal nowadays, so getting a rough idea of wether it works is a good start. And besides, i dont see why an RTX wouldnt be able to do the detailed version too. You'd need to trace more rays, sure, but in theory, sonar behaves enough like light to make it work anyway with a few adjustments, at least as far as i know.
@@Chrischi3TutorialLPs regardless that is a genius idea for a lot of independent or small company's to explore ideas with. Since a real pain in the ass is simulations. because it's either always insanely expensive, not for sale, or requires a huge amount of set up.
@@ALegitimateRU-vidr Start a company thats all about running the simulations thats too exhausting for everyone else to run... interesting idea, i must say.
@@Chrischi3TutorialLPs honestly i'm kinda working on that but for a shop space. Because i'm formally from the independent side of things. And you have zero restrictions there. And i would like to bring a similar to the public. Just sucks how expensive such things are. But baby steps. unless i get super lucky and can form another IRG (independent research group). Though if you as smart as you have lead me to think you are. you start that idea. Because offering that kinda of simulation service without restrictions or monitoring. Oh man, you'll get easy attention.
I would think with this design you'd get a lot of extra dead space outside of the pressure vessel. I would think that you could slide your launch tubes and torpedo tubes outward and into this dead space, leaving a lot less if the tubes in the pressure vessel, which would open up interior space. I would look into mounting as much hardware as you can between the outer skin and the inner hull that you can get away with.
Seems to be the perfect spot for lithium batteries: they can widstand high pressures and putting them inside the actual living space is a fire hazard. Seems to be a win-win to me.
Boy howdy am I glad y'all aren't building subs! I'm sure it's full of the real magic sauce in this "stealth". What kind is anyone's guess... I'll go with some kind of very special foam, but it could be the prayers of schoolkids and we would not know.
Perhaps just use the space as extra emergency ballast tanks. Divide the space into sections and force water out of all of the undamaged ones in case of emergency.
That is the goal but currently crew is still needed to maintain batteries and torpedoes often enough they need access during cruise. As technology continues in improve in reliability I am positive that external batteries and torpedoes will come about. But for now we are still needing human beings to be able to put their hands on these things
like anything on engineering, it's a compromise. planform alignment increases wetted area, frontal area and mass over an efficient cross section of a cylinder. The added volume though could be use for adding stuff.
What is also true about having more complex "AI" and real-time algorithmic computational capabilities is that these hull shapes will give you a set of possible boat locations back, and by tracking the progress of the signal over time, eventually the "true" boat location should be able to be computed. An implication of this, however, is that there is the possibility for a new kind of "morphic" hull (made from titanium?) that would change shape to send a false progression of signals and lead the tracking boat on a wild goose chase. This should be obvious to the folks working on the problem, but the question is whether any such technology is in development.
Thank you! I was thinking about 'shape shifting' hull too but 'morphic' hull is probably a more accurate description. Could be made of titanium or some new age material being researched.
Dolphins use active sonar to locate prey. Thus being more stealthy (having facets) would be an evolutionary advantage to a prey species fish. I wonder if this has happened to any extent.
I suspect that an angular outer hull would have horrific hydrodynamics, meaning that turbulence would cause significant noise at anything above dead slow.
Active sonar was self-defeating to use back when the main place for the sonar was the sub. Nowadays sub drones and stationary sentries are powerful and cheap. I imagine a sub may have "loyal wingmen" doing the pinging.
Seeing this video (maybe because it is somehow related to sonar), I was wondering if you could make a presentation, from an analyst perspective, on multistatic sonar techniques (e.g. which are employed by the different navies...). ... Also read a comment stating, that natural sonar sources from marine life could be used in that case, is that a thing?
Anechoic tiles was used on a few U boats during WW2 but the coating had holes/pits of differant diameters , A kriegsmarine survivor said we never was detected by enemy sonar .........
Is it a known fact there is a conventional inner round steel construction or merely speculation? Given that is correct, when will the angular oyter construction brake down as it cannot withstand the pressure? Is there any scenario where one will rely on the inner construction in a fully functional mode or do we speak of safety to the crew only?
have to say it; F-117 is not a fighter, but an attacker, despite the misnomer "F" in its type number. It was designed to not manoeuvre much and is easily beaten in a turnfight by nearly any other aircraft. It needs to fly in low radar coverage areas, and get out before scrambled fighters can get up to catch it.
2nd that. I am Australian. Keen to see if they go for US based platform or UK based platform. The pros and cons for both would make an interesting video.
@@telinoz1975 No expert here, but I expect it is going to depend on how fast the subs are to be aquired and who can/and will supply them with a possible loan/rental of boats not currently being operated by the supplier.
The French subs we rejected were nuclear, we asked for diesel, why didn't we just say "change of plans" we'll go back to nuclear. I suspect or AUKUS allies were passed off that the French would get the money. As I understand the French was a more recent design than UK, or USA.
At 8:29, you say that "each of those bounces reduces the noise" -- does not each bounce increase the noise and reduce the _signal_ in what reaches back to the sending sonar?
Even if a reflected signal from the water surface and off the bottom comes back to the sender. What good is a reflected signal that took unknown detours and coming from a random position? No distance info, hardly any usable bearing info...
Interesting but the B2 showed that the complex calculations needed for smoothly curved shapes are possible hence there's no longer a need for the flat faceted surfaced of Have Blue and the F-117 Nighthawk. Also, these "stealth" shapes simply deflect the signal away from the emitter so this kind of stealth is ineffective if there is an unpredictable distance between the signal source and the hydrophones (receivers). With radar and planes, it has been suggested that the background radio emissions from cell phone towers be used to illuminate stealth aircraft as the geometry between the towers and the radar receivers would be variable and hence could not be accounted for by the shape alone. Likewise, with a tradition of wireless connected hydrophone buoys and the seismic acquisition techniques of towed hydrophone arrays, such stealth shapes should be easily countered. I would be more interested in meta materials directing the sound around the submarine though what we publicly know of are only effective at specific frequencies and low frequencies at that. Calculations for a selection of frequencies may be computationally difficult perhaps even impossible and the scale of the construction may be very fine for higher frequencies and hence difficult to manufacture.
9:15 but cant u then optermzise the receiver with the same cals then ariving line all cars look same due to aerodynamics so you be about to look for that?
