Stealth Ships: How They Work

[@tadpolman8069]

thank you its been really hard trying to get my destroyer past the coast guard

[@CloroxBleach-uf1nk]

Would like but your at 69 likes

[@jwellipweid2076]

Coast gaurd

[@vinbeezy8538]

@@CloroxBleach-uf1nk good to see you clorox. I am about to head over to some cringe compilations. see you there

[@MouseGoat]

@@jwellipweid2076 naa he means the cost guard, those things ain't cheap after all

[@jwellipweid2076]

@@MouseGoat well then it would be more fun to destroy them.

[@snakesocks]

Ben Rich, the director of Lockheed's "Skunk Works", wrote that they had a prototype stealth ship that worked too well. It's radar defeat was so good that it would return a smaller signal than the waves around it. So to the observer, it looked like a void of perfectly smooth water moving through the ocean. He said that it broke rule zero of stealth; 'As quiet as ambient noise, not quieter!'

[@hanzzel6086]

That reminds me of the current thermal camouflage for infantry. It is so good at dispersing heat that unless you are trying to wage war in -10°C you are gonna stick out like a sore thumb.

[@emberthecatgirl8796]

Imagine that you’re on patrol and all of a sudden the birds’ songs become muted

[@greenbean5186]

baby brain stuff. these people just larp as intellectual.

[@TheEngineer4077]

1:38 Did your submarine drawing sink a destroyer by shooting another submarine at it?

[@richardsia7188]

That's called torpedo

[@lamoona4269]

@@richardsia7188 r/whoosh

[@lamhkak47]

That's called manned torpedo. Italians and Japanese used it. Italian ones have hatches.

[@kirknay]

@@lamhkak47 Baka bomb.

[@UnitSe7en]

@@lamoona4269 Incorrect use of an overused, unimaginative insult only used by idiots _and_ you liked your own comment. How cute.

[@MennoKiel]

It’s rare that you learn so much on a topic, in such a short time. Very impressive. Keep up the good work!

[@by9692]

True

[@liutaurasgrybauskas8377]

I've actually had a chance to see for myself how bad of a reflector a wooden sailing ship can be. Last year we were sailing to Finland to participate in the Tall Ship Races. It was a foggy day, and so we had our radar turned on, since barely anything could be seen through the fog. Suddenly, a ship apeared on our port side. It was a wooden schooner, 30 to 40 meters long, passing no further than 100 meters away. Barely any radar signature was visible. Luckily, it passed through us without crossing our course

[@CasualNavigation]

It just shows that although we get used to modern technology, it doesn't always show everything.

[@jorisd6584]

The Casual Navigator Wouldn't this mean that covering all of the ship's hull with a thin layer of wood would be the ultimate radar protection?

[@CasualNavigation]

Wood is actually invisible to radar so it would just see the metal underneath

[@jorisd6584]

The Casual Navigator Makes sense. Just wanna say that I love your videos! keep it up :)

[@CasualNavigation]

Thanks Joris. Glad you enjoy them

[@adriano5120]

what the hell! there are no ships on this video, just pictures of the sea!

[@pelotudo4717]

found the underrated comment

[@NickJarmusz]

Cursed King Crimson

[@hailtouhou855]

true, This man its Talking to the ocean, is A crazy, kill'em (?)

[@abrokenthing470]

Adriano Sarmento I know right this is clickbait!

[@matthiasmihld9795]

I know dudes talking about battleships but where are they

[@paffycat]

Anyone saying size doesn't matter doesn't know what they're talking about it's not just Size It's Aspect Shape Material Texture ...duh

[@cesarfelipe7138]

You sir just won the internet.

[@blahdolphinjsjsjs3818]

M a t e r i a l

[@henriquetolentino1055]

@@blahdolphinjsjsjs3818 mine is made of high grade steel

[@yoavmor9002]

Honestly this applies much better for women than for men

[@alstef09]

@@yoavmor9002 What?

[@Name-js5uq]

I myself loved the length of this video, I watched every second of it and thought it was wonderful, great job you did.

[@platinumchillheart3044]

Steve Kay•same here

[@laszlomeszaros247]

Me too!

[@cenowador]

bro, just paint it like a fish or whatever

[@nbtwall7287]

holy shit

[@ferretzim8694]

Or make it a tanker.

[@okrion9]

Illusion 100

[@majorgeneraljohnson8212]

Make it goddamn ocean color or somethin

[@makoyloyola4986]

What the F*** paint it like fish 🐠

[@whispofwords2590]

I still cant decide rather or not the Zumwalt is one of the ugliest warship I've every seen or one of the most beautiful.

[@pezpengy9308]

it doesnt matter, because shes commanded by captain kirk. thats all that matters.

[@hazuanmajek6002]

Meow

[@PvtMartin78]

Pretty sure the Novgorod wins that award.

[@sherlockhooves574]

@CR BZ Submarines have a lot of drawbacks, and you don't always need that much stealth. Sure, a sub can pass very close to almost any vessel undetected, but there's a lot of ocean. If you can spot the enemy and maneuver around them before they spot you, that's all the stealth you need.

[@whispofwords2590]

@CR BZ buddy, not to antagonize but theres alot wrong with that statement. For one, they arent meant to be stealthy as in difficult to detect in the first place. Instead they are designed to make it hard for the detection equipment of enemy surface combatants to first find them, percieve them as a threat, and then direct ordnance at them. Two, everything cant be a submarine. Everyone in the online military community seems to have this impression that if one thing does one job well everyone should devote everything towards it. But a submarine is not imposing; its not a deterring threat and its not good for gunboat diplomacy. Submarines also cannot offer consistent artillery support for ground forces, which if I remember correctly is one of the things the Zumwalt is going to excel at once they find a suitable gun. What I'm basically trying to say is that Zumwalts stealth is meant to give it an edge over other surface combatants, particularly other destroyers and in some cases land based missiles by making it harder to detect and hit. Its not meant to make it "sneaky" like a submarine. Besides, weve already got a substantial submarine fleet.

[@on_spikes6867]

would have been nice if you included any footage of the stealth ships.

[@killian9314]

DDG 1003 John Cena The sneakiest boi on the seven seas

[@timweatherill3738]

Uh, yeah, the USS Zumwalt IS the stealth ship he was describing, so you did just watch one.

[@ICDedPeplArisen]

@@timweatherill3738 he was making a joke on how they are undetectable.

[@JinxProLuhut]

@@timweatherill3738 dont ruin it

[@thatfatguyinmcdonaldseatin6389]

tim weatherill r/woooooosh

[@thomasnorge224]

Paint it like a island. And the enemy will never know.

[@AdamMGTF]

Given your name. I assume you know this was done in ww2. Not to mention the ship painted white when hiding after pq17 and pretended to be an iceberg 😅

[@floriansmulders2003]

there was a dutch ship who did this simple history did a video about it

[@lizmacleod5523]

That happened in real life, a carrier was about to be found, so they covered it in leaves and grass, then it would only move at night.

[@hushpuppy1735]

liz macleod Nah, it was a minesweeper

[@FlyLeah]

Vietnamese: write that down write that down

[@jerrymartin7019]

"There are five total factors that effect radar effectiveness. In order to remember them, simply use the phrase "Ass Mountain"

[@lapistaoftheparadise4627]

I don't get it

[@Sev7.]

@@lapistaoftheparadise4627 ASS = Acoustic, Shape, Size Mountain = MT = Material, Texture

[@Attaxalotl]

Every mnemonic device besides this is bad.

[@A6Legit]

@@Sev7. aspect?

[@SirDavidAsher]

lmao!

[@inventor121]

So you're telling me a wooden rowboat made of nothing but flat panels of plywood is the ultimate stealth ship?

[@eklhaft4531]

Well it is but probably not very good of a battleship...

[@cerealkiller7143]

@@eklhaft4531 They cannot shoot at you if they cannot see you.

[@alexanderszewczyk8919]

What if u build of wood outside and inside with steel maybe that will work

[@rubytheminer9546]

@@alexanderszewczyk8919 genius

[@rixille]

@@alexanderszewczyk8919 A wooden clad modern warship? Amusing.

[@roji556]

How do you make a stealth ship? You make a Submarine.

[@IndoLiberation]

*A diesel one with AIP

[@greenvoodoo8366]

yes but boat

[@WalrusWinking]

A submarine cannot carry the armament that a destroyer can, and older submarines have been getting easier and easier to detect.

[@N75911_]

*Laughs in Sub-Hunter aircraft*

[@Canwegetsubswithnovideos-ox5vs]

Still Is viable to radar

[@NiekLipper]

I always love the fact that at some point stealth ships were so "good" at scattering radar that they appeared as "holes in the sea". Forcing them to intentionally make the ships less stealthy

[@lukeg5540]

How would the radar scattering make them appear as holes in the sea? If the radar doesn't return then it cant necessarily know whether its a hole in the sea, or am I misunderstanding? How would the radar find a hole in the sea unless everything else is reflecting radar? I must be mistaken.

[@matthewnovak3095]

@@lukeg5540 The ocean isn’t perfectly flat, so the ship would appear as a flat space in an ocean that has waves.

[@lukeg5540]

@@matthewnovak3095 Do ocean waves reflect radar?

[@matthewnovak3095]

@@lukeg5540 another comment stated so

[@NephilaClavata]

Great video, definitely liked the longer format. Thanks!

[@CasualNavigation]

Thanks Nephila. I appreciate the feedback!

[@antonman1234]

@@CasualNavigation why do I like your videos too much

[@tieck4408]

Solid content, strangely relaxing delivery

[@CasualNavigation]

Cheers passenger2ndclass

[@474yx]

@Pavan Kumar Aroused and relaxed are two different words, and have two very different meanings.

[@andraslibal]

10 minutes is a pleasant length for an informative video

[@bearbumxx2600]

Thanks KZbin for recommending me random yet compelling videos

[@jungleb]

I love the format! Please, don't stop

[@StkyDkNMeBlz]

Woah there

[@chancantcommunicate]

*Just throw some Splash Potion Of Invisibility on the ship*

[@juliandebrouwer9118]

Or a lingering: the whole fleet will float through it and all will be invisible

[@philipblake5609]

@@juliandebrouwer9118 u smart guy

[@idonotlikeboats9328]

Ayatø they already do that

[@xrcgaming]

Just put the ship in your inventory when you see someone and pull it out when there gone

[@chancantcommunicate]

Damn minecrafters are smart asf

[@Ma-ttga]

-"Private! I didn't see you this morning at the camouflage exercise!" -"Thank you sir!"

[@TheOriginalBlue62]

In regards to texture, the specific paint used may also be partly radar absorbent, resulting n a smaller echo being created at all. And interestingly enough, choice of material actually resulted in a couple early stealth aircraft being created during WW2. Both the Mosquito fighter-bomber and (although it never got past prototype and noone learned for decades) the HO-229 had very low radar cross sections compared to their actual size because of their wooden construction.

[@zippersocks]

You laid out the info very well and your delivery was on as well. I’d say longer works great for your vids.

[@GarfieldRex]

Oh is the third video in a row I watch of this channel. New sub here :) glad I found it

[@alanriddell833]

Its not just subs he does other water stuff too...

[@VisakhS]

Awesome explanation. I loved it. The length is OK because it was needed to make sense. Appreciate it. Thank you. 👍🏽❤️

[@denverflatpackjedithornton]

Absolutely enjoyed that breakdown you are a gentleman and a scholar this is about the 6th video of watched of yours in the last couple of days so keep up the good work

[@weirdguy564]

You add ballast tanks, nuclear power plant, dive planes, an oxygen generator, double hull in the shape of a tube, and arm it with torpedo tubes and Tomahawk missile tubes, and a periscope.

[@newgammer101]

weirdguy564 diesel electric subs are stealthier

[@hunternelson3018]

The issue with that is sonar

[@RT_today]

The most calm, soothing voice I've heard in a long time. This guy needs to do voice over work. e-Books, GPS everything. Could listen to this all day. lol

[@REDRAWVISIONS]

Will check out more of your videos ... This one is cool as it is narrated well. Yes, it's basic ... but that is precisely what is required when one is learning for the first time.

[@doggonemess1]

1:50 Use a rowboat - the original stealth craft. :)

[@owenchristie6958]

I mean your not wrong

[@aleisterlavey9716]

Swim, you lazzy dog!

[@keatomic]

Yes, dear friend. I do indeed enjoy the longer informational video format. Rock on.

[@AzureScintillae]

The first stealth ship is the netherland ship from ww2, they were able to be hidden in plain sight. Using foilage, dirt, paint, wood, sand & rocks While japanese ships are close by. They were able to get to Australia.

[@calebr4191]

I just discovered your channel, and it's incredibly interesting! On the topic of stealth ships, I'd love to see you go over some of the weirder designs like the Sea Shadow.

[@benschmeel4189]

I love it that KZbin is constantly recommending videos to me with questions that I have never and would have never asked myself

[@geronimo.v8827]

This is really cool I've always wondered what makes a ship stealthy and I never knew radidar reflected in different angles I thought it went straight back

[@dillanmcanally4626]

This is a great video, I originally used these because the calm voice let me sleep, but I’m a nerd and always end up paying attention to the info in the videos, great content

[@jaybuss3447]

I live at the town where BIW is and they are building this ship right now. I can practically see it from my place, it’s beautiful and majestic yeah, proud to live in this town.

[@Animalwon]

I enjoyed your longer educational videos, not just due to the extended talking points but because of the more extensive animations needed on difficult or complex subjects. I enjoyed seeing the various search patterns in animated form rather than the talking alone would give me. THANKS, again for all your efforts.

[@zbee_]

I enjoyed this longer video quite a bit, it's what made me subscribe actually

[@RobertBardos]

My preferred length of a documentary is between 10-20 mins so thanks for asking and offering to make slightly longer content with additional details

[@Zirkobi]

The depth of these videos, your relaxing voice and everything you add here is really great! Definitely earned another subscriber and I can only hope that you will get many more. You, sir, you deserve to be rewarded for the amazing work you are doing! :)

[@alexd4219]

Really enjoy the long form video going through your catalog. The combo of physics and practical application makes for a video representing KZbin at its best 😊

[@xxdeserthunterxx2819]

You could have mentioned the greatest stealth ship ever, the Visby class corvette

[@derain95]

I was thinking the same... *Välfärd intensifies*

[@xxdeserthunterxx2819]

@@derain95 haha

[@ussocom3644]

Equipped with the latest Volvo technology and a swedish gay pride dazzle pattern.

[@xxdeserthunterxx2819]

@@ussocom3644 no u

[@Mihalyofficial]

I prefer these longer technical videos as they are also a good refresher to my previous schooling and really interesting in general. Thanks.

[@JayV688]

You forgot to include the last element. The element of surprise!

[@IndoLiberation]

Thats why you dont build "stealth ship" submarines are there for the job :)

[@slowfox532]

Longer explanations are verry welcome. I understand now things I coud never figure out before. Thank you and keep the good work up.

[@REDRAWVISIONS]

Wow ... have just checked your other videos ... some excellent topics - look forward to watching.

[@MrFearzone91]

I’m also a navigator, and I love your content so much! Keep up the good work! Looking towards your new videos!

[@arielapp9469]

stealth has several different objectives depends on where you are, and what you want to do in case you do get noticed, and the weapons the enemy possess. for example, some shapes make the ship looks BIGGER, because, the enemy has radar seeking missiles, so, in order to confuse them, you want to look bigger, so when they target you, they'll miss and hit the water.

[@happythings2595]

As a sailor myself I find the details great. Good work on these vids. Sometimes just nice to remind yourself why we do what we do.

[@thijsrikkerink6333]

Really nice channel! This way I learn about my interests, and have fun while doing it! Keep it up sir :).

[@hadeez2651]

they may take more effort to make but however they are even more so enjoyable and informatical thanks a lot for doing the thing that you do for us man!

[@GamalKevin]

There might be a perfect stealth ship that we don't even know it's name

[@mariosebastiani3214]

Thanks for the video, you kept it quite short for a similar topic, yet covered all the main aspects in a good way. Only a note: density goes against wave propagation in a medium; it is elastic reaction that increases it. Water is almost unncompressible, while air can be easily compressedby pressure waves; that's why water propagates sounds at much higher speed than air. Iron has a higher elastic module, thus the propagation reaches 5000 m/s through it.

[@thaddeusmccaustland8023]

*First one must acquire the fabled Stygian Crystals from Aeten II, then one must simply place it within ones cloaking device....*

[@zelda_smile]

Can you do a vid on how to make a stealth space ship please

[@enoz2]

i loved this video , it really allows me to appreciate the engineering that went into the zumwalt by letting me understand part of the engineering that went behind it . Great work!

[@CasualNavigation]

Thanks Fisherman Joe. Glad you enjoyed the video and it helped understanding the vessel's construction.

[@dreska255]

They can't afford hq graphics so they made low-poly battleships

[@excellenceinanimation960]

Hahahaha

[@mlgproplayer2915]

True...

[@pompeymonkey3271]

Closer to the truth than you'll ever know ;)

[@Turbomachinsky]

Such an informative video, thank you so much! I'm more of an aviation enthusiast myself but I was always intrigued by those weird geometries on stealth aircraft, to the extent of deteriorating aerodynamic qualities. It makes so much more sense now!

[@joachimh3402]

Nice video, keep up the good work!!

[@CasualNavigation]

Thanks Joachim.

[@FatChunkyFarmer]

Just want to say I absolutely love your work. Such great production quality, interesting content and really clear concise voiceover! One of my favourite channels!

[@billiondollardan]

The fact that the USS LBJ has a steel superstructure I think is just more proof that these ships were failing at their mission.

[@prawnjohn]

Casual Nav. This video has answered the question i have wanted to know for a couple of years . I wondered why the shape of battleships were flush at Port and Starboard rather than the older type shape of a ship.

[@Joege]

Elon musk: *let me introduce you to the TESLA CYBER BOAT*

[@Attaxalotl]

You have won this comment section.

[@Joege]

@@Attaxalotl oh god i do not remember leaving such cheesy comment

[@Attaxalotl]

@@Joege Well you are still victorious.

[@josephseed7734]

Cyber Submarine

[@aeHyde]

I built the deckhouse for the ddg 1000 and 1001. totally awesome job. loved every minute.

[@ChaosGI]

In the end: 'Hope you found the information today useful' Me: ye sure i was planning to make anti stealth ship systems and now i know how to!

[@Jiilaker]

The people who build f22, abrams, uss stealth destroyer, apple, ford gt and many other technologically advance stuff from US are totally brilliant. I admire you people soooo much

[@arkan7rb]

wonderful long vid keep up thx

[@subinnathsharma4555]

Nice way to deliver a complex information..in a short time too....Good work and thank you.

[@henforr]

"How do you make a stealth ship" HMS Gotland "Hold My Beer"

[@AlexKall]

Or Visby? 🤷‍♂️

[@uncomfysapphic8415]

I already knew every point he was going to say in this video yet for some reason i still watched. Very informative even though i already knew all the aspects of how radar works and how to fool it. Good job.

[@ChocolateCoveredBean]

How to make a stealth ship: Tell the U.S. Navy that you’ve a secret design for a stealth ship. Secure money from them to build the ship, and when they ask to see it, show them your ship in the harbour. They will ask, “where is the ship” to which you reply with a subtle nose tap. This will eventually get into the press and enemies of America will literally shit themselves over a boat that they can’t see, resulting in surrender from all hostile nations. You effectively made world peace, and a hefty profit too.

[@penkagenova7073]

Korea would just nuke the ships if somewhere of their area and start ww3

[@joshuaallen2176]

Yes! I've had 3 or 4 questions that haven't been answered until this video.

[@KuraIthys]

You can see a lot of tradeoffs in action. The F-117 follows most of the criteria, yet something like the B-2 ignores several of them, or doesn't go all out with them. Supposedly the F-117 was built on the idea that a diamond shape was the stealthiest, but for obvious reasons, that won't fly, so they modified it from that ideal the least amount possible to get the thing to be able to fly.

[@peterc9243]

The F-117 was designed that way because computers at that time were not capable of calculating Radar Cross Sections (RCS) of more complex designs, so they went for flat surfaces. This video is fairly accurate for a "how it works" sorta thing, but in the engineering and physics level it gets lots of things wrong. The way radar interacts really is far more complex than this. If you want I can explain you more in depth how radar actually works and how to achieve Low Observability (LO).

[@johnspecht72]

Longer videos with more information are my favourites. All of our videos are appreciated.

[@manolistopakas2117]

Nice video! By the way what's the 3D program that you used during the first 20sec?

[@CasualNavigation]

Thanks Manos. The first part actually comes from a Public Domain video by the US Department of Defence. You can find it here: www.dvidshub.net/video/487599/all-hands-update-pcu-zumwalt-commissioning

[@irecycleoxygen2730]

I have no interest in ships but I’ve been watching your videos for an hour. Good job.

[@Mendo_xd]

I can answer this much faster. Just make sure to apply the WD-40.

[@EmeraldComposer]

I live in Maine, which is home to Bath Iron Works, a place that builds these ships for the military. It's interesting to learn about their uses and why these stealth ships look so distinctively angular. I'm fairly sure that the last shot of the ship in the harbor is in Bath, for that harbor area has a bridge poised in the background such as that, so I may have seen that ship in real life! Very cool to think about!

[@johnkean6852]

Doh - given all our secrets away 🙄 we'll have to go back to the drawing board!

[@lodevijk]

I prefer the longer videos. 10-14 minutes is perfect.

[@patavinity1262]

The plural of 'medium' is 'media'.

[@A6Legit]

Not worried about it

[@damianp7313]

This was a great video... I always wondered about the how the stealth" shapes worked ... well I had some idea but this explained it nicely

[@noodleoflake965]

Bro I can barely spot a container ship at a beach. How do you think anyone’s going to spot that?

[@jimmeeks320]

New to this channel... Just wanted to let you all know that I absolutely love the material you cover!!!!

[@isakjohansson7134]

"The hangar doors are covered with a door"

[@gravedigr12]

only seen 3 of your videos but so far so good I actually enjoyed them

[@RediscoveryChannel2021]

What if you could submerge them under water?

[@brunoraoni]

That's called a U-boat or a Submarine...

[@ivanlamb6519]

@@brunoraoni nooo hes saying what if you could just put it underwater. Then nobody could see it.

[@brunoraoni]

@@ivanlamb6519 Again, like i said, that would be called a submarine. You can't simply build a ship and make it go underwater, you need oxygen tanks, ballast tanks, you need eletrical or nuclear engines so that when the ship goes underwater, it doesn't suffocate the crew with carbon dioxide, you need to completely change the hull so that it would be able to sail underwater and to not implode because of the pressure and kill everyone inside.

[@ivanlamb6519]

@@brunoraoni no dude you take the boat then its just underwater come on this is basic science

[@madhvendrasingh1131]

so simpky yet exhaustively informative. thank you. pls keep this up.

[@Tewemeh2ter]

8:51 Casual navigation: there are no smooth surfaces Obvious smooth spinning radar and other smoothed out domes on top of bridge: am I a joke to you?

[@Carewolf]

Yes, also the radar actively signals its presence to everybody around when running (sending out signals is how radar works). They need to be not just disabled but completely removed to achieve real combat stealth.

[@ben-brady]

"How we gonna get this past them, they can see it from miles away" *drum beat starts playing* "I want it painted black"

[@mikaxms]

You can also detect by radiation. Ships and submarines that use nuclear reactors slightly radiate the seawater used for cooling.

[@Rockbagaren]

Thats why the swedish gotland class submarine use stirling engines

[@RyanPratten]

As a child, I always wanted to join the navy. Sadly, it turns out I have a hearing impediment which the navy does not allow for. I find your videos extremely informative and interesting.

[@bsnxenogear]

Zumwalt class can actually submerge. That's why it's a stealth ship.

[@GreyWolfLeaderTW]

A funny thing about the design of these modern stealth ships is that they look like low-polygon ship models from an old video game called Star Fighter 3000. The models for surface ships in that game had the sharp angels, flat surfaces, and upward sloping sides of stealth ships.

[@DRB-Octane]

you make it go underwater and call it a submarine!

[@tonycorrazy]

I enjoyed this longer vid and found it well worth watching. Thank you.

[@wanderingfido]

Q: How do you make a stealth ship? A: You kinda don't. You PRETEND it's a stealth ship and hope you don't gotta go to war when people find out the awful awful truth.

[@thomascrabtree]

Missed one important radar point - Modern short-wave radars look for specific stress-related imperfections caused during the manufacturing process in the material used to construct an object, say the titanium in the F-35. An AF guy told me this was a concern in the mid-70's, so it's been known about for a long time. He said the first titanium based jets they were testing "lit up like a christmas tree" despite them expecting the exact opposite given the latest design / shape methods etc and new novel materials / compounds... This was material provided by the best (at the time) mills in the US, so the defence contractors had to develop an entirely new manufacturing process in-house and trash the vast majority of the produced material as not fit for purpose. Apparently they were trashing about 98.5% of what they used and roughly (not sure) 1.5% was useful, similar to how CPU silicon is binned these days.