Why are Submarines Black and Cruise Ships White?
If you have previously heard of explanations on why submarines are black, well, you need to watch this video. It's not what you think!
Footage courtesy of U.S. Navy used under the Creative Commons Attribution license. Thank you for that!
Note: "The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement."
REFERENCES:
www.navysbir.com/n16_1/N161-0...
www.navsource.org/archives/08/...
makeyourdepth.blogspot.com/200...
www.todayifoundout.com/index....
en.wikipedia.org/wiki/HMS_Van...
en.wikipedia.org/wiki/HMS_Tor...)
www.ripublication.com/ijaersp...
core.ac.uk/download/pdf/77039...
web.archive.org/web/200609121...
www.nature.com/articles/212284a0
www.researchgate.net/publicat...
link.springer.com/article/10....
Submarines are black, but sometimes they're blue We're "Not What You Think", thanks for watching through!
Cool
Submarines are black, but sometimes they're blue I wrote this awful poem Because I love you
Why F-22 doesnt have helmet display system and AIM-9X?
Hey, I was wondering if you can do one video of something Chinese military, like a facts video. Do you know what I mean?
What about the yellow one we all live in?
The cruise ship needs to be white so the other iceberg think it's just another iceberg and not sink it like the Titanic
Lmao
Lol!
Big brain move
Obviously Titanic builder didn't understand this "principle" at the time. LOL.
Woooooosh
I like how you spent aprox 5 minutes explaining why submarines are black, but it just took you 10 seconds to explain why cruise ships are white. Great video :)
Only if everything was as simple as cruise ships being white!
@@NotWhatYouThink hahaha you always have to leave the best for the end
@@vibing8674 Cruise ships (and passenger planes) being painted white is somewhat common knowledge. I had no idea why submarines were painted that color. I suspected it was because of camouflage but if that were the case, it wouldn't have been worth making this video.
@@Elthenar I wasn't criticizing in any way, actually I didnt know myself why they were painted that way, I just found it funny the effort he took to explain us why the were painted that way.
@@vibing8674 I wasn't trying to roast you. I was just explaining why the video caught me eye. It asked an obvious question and one I didn't realize I had clue as to the answer.
I love how he talked about submarines for more than 6 minutes and explained the reason for white color in cruise ships in only like 5 seconds
I came for submarines I am happy
I mean, atleast he got to the point instead of padding it out for 30 minutes
Well a cruise ship is white because well it looks much better
So would a Cruise Ship Submarine look like a Zebra?
Stolen
Imagine making subs so stealthy that they literally don’t notice until they run into each other.
They still didn't find out what happened until a little after wards.
The French drive their submarines exactly the same way they drive their cars, they're probably covered in dents from many minor accidents
SONAR is 10 steps ahead of your comment.
@@vic5594 I'm not familiar with the intricacies of French driving - How do they drive??
@@JoshuaNicoll witpyeiietuwtet
Weps: "The torpedoes won't fire, sir!" Captn: "Have you tried turning it off and on again?"
Control, Alt, Delete!!
Torpedo: *Red when armed* That one guy: *slaps the torpedo*
Alt F4
Weps: “Sir, I think our torpedoes are out of battery”
"Barnacles!" "Stop cussing like them spongbob characters." "No sir. The torpedo hatch is has been locked shut by barnacles!"
Why is Windows' blue screen blue? because it happened so often back then, in the long run, blue helped to reduce the growth of a bionic film of moss on your monitor.
@@FanofDocumentaries They didn't. It's only black on internal builds, such as internal Win8 builds. Insider builds use orange and green, and public releases use blue.
No wait really?
I feel sarcasm
@@TheDeepDiveLLC nope
It's true. I read it on the internet. The Internet that's on the computers nowadays..
I learned something interesting about ocean liners in the past: Back when they were mostly powered by coal, the hulls of liners were painted black to hide coal marks and coal dust that would often get onto the ships during refuelling, so the black paint was made to hide this to make them looks more attractive to customers. When oil started being used more often, they kept the black colour for the longest time since it was more or less seen as a common sight for liners to be black, but once cruise ships started taking over along with the white colours being easier to keep them cooler with white reflecting the heat from them, black hull ships for the most part went out of style.
Wow.
I really love the 6 minute and 49 seconds worth of explanation of why submarines are black and then the 12 second explanation of why cruise ships are white. gotta love the professional work this man is doing lmfao.
Submarine: is just chilling under the water Random Axis plane: That’s one big ass shark
Lmao. I'm dying.
🤬🤬
_why does the shark have A big ass_
@@ncpdswordshielddivision2240 Because it's a big ass shark. It's like asking why does a hammerhead shark have a hammerhead :D
Or does it? Let's say hypothetically, the submarine has a big ass, implying that them thangs be clappin underwater when being stealthy, so not so stealthy anymore now is it? You claim the submarine has a big ass, but say it's stealthy. curious.
Finally they ended up with fluorescent pink "our enemies would never imagine this pink stuff is a submarine". Clever !
I painted my snow shovel fluorescent pink so that no one would steal it, cause no one wants a pink shovel. It worked. Perhaps thats something the Navy should consider.
I loved that old movie.
Pink submarines can sink trucks iv never seen a black one do that
I would go for brown and make it look like an enormous turd from the plane
In the second world war II the sas actually painted their Jeeps pink so they were better camouflaged in the desert.
As a young man, I worked for a Ashland Chemical company facility making Carbon Black. It is basically soot from burning oil in a furnace. I knew it was used to make rubber tires stronger but didn’t know about submarines. Thanks for the info.
Wow. The quality of your videos are always top notch. Where some other YT channels are satisfied with half assed “research” yours alway go deep and have real substance behind them. Also the humor and the video material and editing is super good too. Keep it up!
"Destroyer dead ahead!, Dive, Dive,Dive!" Sub: this action will submerge the vessel, are you sure? -- OK! OK! now dive!--- Sub: periscope is not yet extended and prevents dive.exe from loading, extend periscope? -YEEESS! Periscope is in use or not responding. Wait for it to respond? --NOOO! End periscope task! An unforeseen error has occured and windows needs to close. ---Aaaaah! ...2 minutes later.... Windows could not find a suitable driver for the unknown device 'Balast tank', search the net fore drivers?
Fucking operating system lmfao
What the fuj ??
Clippy appears. "It looks like you are trying to avoid a destroyer, would you like some help with that?"
Yes, I would like to join. Where do I sign.
Windows requires an update. Update and shutdown or update and restart? -WHY ARE THESE THE ONLY TWO OPTIONS
I really thought he forgot to explain why cruise ships painted in white🤣🤣🤣 but he explains in just a few seconds 🤣🤣
We almost forgot about the cruise ships, almost 😉
Not what u think
That's not funny its hilarious
@@NotWhatYouThink 🤣🤣🤣
@Saved By Jesus Dude... we just want to watch some KZhead videos, not copypasta conspiracies.
I could listen to this guy talk all day long. One of the best channels on KZhead.
Keep being funny!🤣 and providing me and my 9yr old son with fascinating information! Thank you!👍🏾
Submarine colliding with each other Submarine A: It's my fault, it's because I'm too silent... Submarine B: nah, gotta be my mistake, because I'm too good...
British and French submarines may confess to being mistaken/at fault, but only Canadian submarines apologize!
@@NotWhatYouThink Good one
@@NotWhatYouThink French submarines should be white by that logic(French surrender easily)
@@noknowncomorbidities you do realise the French had more wars then just the second world war?
@@sjonnieplayfull5859 you do realize he made a joke?
Excellent explanation, so complete and simple. My congratulations and gratitude
Loved how you integrated the BSOD sound in your video.
Commander: we have to paint the submarine again... Crew: dammit
Bru you have no idea, glad af I'm not deck div
Fun fact: cargo ships get repainted non-stop... Almost. Deck crew ftw!
but sir, last night you told me that once you go black, you never.... "see me in my quaters in five, sailior!"
@@deh6724 Every f****** in-port period.....it's unending. Made even worse when those damn needle guns keep falling apart.
@@HaussPray Spoken like someone that has spent time in Deck Div.
Shit, that Blue Screen Of Death almost gave me a heart attack
😂🤣🤣🤣🤣🤣😂
watching youtube on your break, ensign?
😂
You and me both 😁
Me too.
thanks for this, a little wiser with random facts everyday and i love it
Good Video! A lot of extra information! I never even wondered why tires are black when rubber is white. I should have wondered about that one.
the carbon powder in car tyres is also used to make them electrical conductcive and thereby ground the vehicle. Otherwise you would get a slap everytime you leave or enter the car from the static electricity built up by the Tyre/Road and wind friction during driving.
I've been slapped a few times as well while driving the car! Like when you turn down the wrong street, the wife leans over and slaps me one right across the face. Just not sure which type of slap hurts the most though!
Thats wrong. I've gotten static shocks when leaving a car
Rykehuss: You are right, I also got some little Tingling in my fingers when I touched the wrong car door at the wrong time. But there were tests with Cars with carbon-free tyres wih ended up letting people lose consciusness, so the grounding might not be perfect (But nobody can really expect that. e rubber-carbon mixture is no copper wire after all). And also: Sometimes you might be the one wearing the sythetic pullover and being electrically charged, so don't wonder if you get a shock by touching something.
Jonas, then why do they tell you a car is the safest place in a lightning storm? I haven't checked, but I have big doubts that if you put a multi meter continuity tester on good tread to car frame etc , you'll get a good connection.
Apparently not all tires have this. Twenty years ago I got new tires and would get the most horrible shock when exiting the car. They were an off brand tires I bought because they were cheaper than the others. Got rid of them quickly.
That Windows Sound still scares me to Death...
Those of us who saw this video are now in an excusive club: We have all simultaneously died laughing while having a heart attack.
I learned to make sure to turn off the speakers before powering it up
About 1 am mom's pissed lol
I once ran a Banbury master mixing unit, the massive oven at a tire factory that cooks all the ingredients to create rubber. The material described here as carbon black is, in the industry, called lamp black.
Love how the cruise 🛳 ship colour segment lasted about 3 seconds at the end lol, still good info on the Subs
Painters: How many times do we need to repaint this damn thing. Scientists: YES !
It was scientifically decided once. How many times do we need to explain this to morons. Apparently you just keep popping up.
lolol
@@toddhercules1885 calm down
So, a couple of corrections for you. The US Navy was using the rubber tiles prior to the 80s. Also, we do paint the tiles black. And the red antifouling paint is no longer used. They formulated a black antifouling paint.
He still explained why they were at some point red
also, they are not purely rubber. they are a rubber-ceramic mix. and the hull is a ceramic-metal alloy.
@@mythmurzin The exact composition of the tiles is classified but they are rubber. The hull is HY-80 steel.
I love this video so much because my grandpa was in the navy and one of the things he told me mainly because I asked him was why submarines were black and he told me that is wasn't actually a paint and that it helped with them not being detected as well by sonar and chances are he told me about the sound part I just don't remember because I was only 10 at the time but he passed away in 2016 and I miss him everyday because he was the only person close to a dad I had
You are right again! It was not what I thought. Great video! Thanks again.
You know, I thought "Don't put windows on a submarine" would have been common sense.
Hahahaha 👍
LOL! Good one!
The reason the Royal Australian Navy doesn't have subs anymore is because they fitted flyscreens to the windows!
@@nigelliam153 they have to keep the water flies out some way
Why not ? The Trieste a submersible reached 10K metres in the Mariana Trench and it had a window (of sorts).
I don’t often laugh out loud watching videos but the Blue Screen of Death did it for me, twice 😆
Same here! A good belly laugh both times. I'm amazed how those sounds still totally got my attention and instantly caused a small rush of adrenaline. I'm still breathing a little faster than normal. And it's been well over two decades since I experienced the real thing.
Windows? That's OK. Screen doors? Not so much
@@brett4264 When the first one came up, I actually thought it was my computer...lol...then I caught on.
I absolutely appreciate all your videos I’ve watched. The amount of actual useful information throughout the whole video is awesome. All the info you provided flows so nicely and I always feel I’ve learned more than I thought I would’ve. I’m hooked on your channel. Thank you very much for all your content. Cheers and have a great day.
3:17 - This is a well-known issue. Submarines are basically invisible to passive sonar when moving directly towards that sonar, because the whole body of the submarine blocks the noise of its engines. It can happen regardless of the tiles. And, even with the anechoic tiles, if the submarines were approaching at an angle, their passive sonar would have detected the other's engine noise.
The Microsoft Blue Screen of death was absolutely hilarious, thanks for putting that in! 😂😂
why subs are black, science, why cruise ships are white, money. no surprise there
Exactly!
I mean to be fair it is still science. Just applied to save money :P
old cruise ship were black to avoid to keep repainting them due to dark coal dust
That plus white looks better.
@@idontcare7961 And what does that have to do with the video????
Also: cruise ships *used to* be black because they used coal and the black paint was hiding the coal traces
The reason for tire rubber being black is also the result of the process of vulcanisation... For the rest, great and instructive video.
The "Yellow Submarine" of beatles is about the US military experiment about what colors to use in their subs
they made the crew sing how they were all still alive. human guinea pigs. sick.
Research submarines are painted yellow for the exact opposite reason that military submarines are black. So they can be seen easily.
the jokes are really good, keep them coming!
Yeah. I had a bad day, i cant stop smiling while watching the video because of the jokes
1:06 Who would've thought that the best color to camouflage with in water was blue? Maybe everybody ever.
@QKe is it really?
@QKe Water is blue for a similar reason to the sky being blue. Because our atmosphere reflects more blue light than any other, at least until sunset when the angle and intensity of the sun starts to change, iirc.
Another excellent video. Love the Windows humour!
Tires can be made without carbon black, using silica as a filler. However the non black silica tires were not selling as good as usual black tires. Nowadays most tires companies could manufacture tire without carbon black but still a tiny fraction is added (a few percents) to keep the tire black for customers.
why not use carbon as the main filler again?
@@tioa.p.1058 Silica gives better mechanical performances to the tire, for instance a lower rolling resistance which is a good asset to reduce fuel consumption
@@martrf9620 owhh, thanks for reply bro, can i get some article/journal about using silica as a tire filler?
Rest in peace to the 53 sailors on the Indonesian submarine that sank
It crashed. All are dead.
Crashed not sank subs are supposed to sink
@@kunkka5491 Be respectful .
@@lucasdunn2717 It didn't crash anything, it just sank. Submarine are supposed to _dive_ , not sink
One question...I think all submarines carry dangerous missile ...and powder......didn't it blast?
windows's blue screen of death, one legendary trait that put in effect to all version of windows since windows 3.11 up to windows 10.. talking about inheritance.. albeit switched on different intensity ... cannot say about windows 11, still spent my leisure time mostly with windows 10
This is cool... I've worked on modern submarines and this was pretty cool to watch
I love these videos, you are growing so fast!!! hope you get 1 mil by the end of the year
I legit got a bluescreen in the first 30 seconds of this video by coincidence, so when your bluescreen popped up at around 2:30 I thought I got another one for a second. Nice.
Still running Windows 95? What a loyal fan.
Man. Things learned today 🤯 pretty cool Kinda like how a UTI relief aid includes orange dye as active ingredient.
Props to all the research for the video! :)
Why are Submarines Black? Because the sailors were upset at being laughed at when the subs were painted pink.
There's a film about that ....
@@frostyrobot7689 And while the humor is light compared to the movies today, it's still a good film.
@@frostyrobot7689 And a show, "Operation Petticoat"
@@MonkeyJedi99 Bingo !
@@MonkeyJedi99 lmao a true classic that shows an early Philippines, which is rare in films as a Filipino myself
Thank you, I love these videos! Really do :) you're capturing an audience in high quality naval information that doesn't really already exist on KZhead (well there's also Casual Navigation but he's more civilian-maritime focused), so the field is yours!
We appreciate your kind words, John ☺️ We have said on numerous occasions that quality content makes for quality audience, and we are very happy to see it’s working out that way.
I remember that around 1996 a colleague told me that the US Navy switched their communications - or something like that - to Windows NT. We both shook our heads. About one or two years later on the news: The US Navy lost contact to their submarines etc.. Can anyone believe that?
The end tho :)) thanks for the vid, really good content
I like it how you just talk about a whole paragraph about submarines. But with cruise ships, you just talk with a few words 🤣
How long do you think a paragraph is?
My Gramps used to work at the vickers shipyard where the British subs were made and he told me a story before he passed about 2 lads who he worked with that ended up going to prison. They stole some of the rubber tiles and not realising that the phones were tapped called the soviet embassy to attempt to sell them. Hahaha rip Gramps x
I love the editing of this video)
Excellent information. Can anyone tell please at 5:04 of the video, what are that fountains coming out of the submarine. Thanks.
I found this channel on 2k subscribers. now it's 146k and I'm a regular viewer. keep going ❤️❤️
3:46 - did some of the anechoic tiles fall off?!
Yes exactly.
@@NotWhatYouThink Where and what part
@@ratte7640 look at the bottom left of your screen at 3:46 to red pieces are visible That’s where the tiles would be
@@cowerdnerddespacito9518 Interestingly enough, the UK’s Defence Science and Technology Laboratory refused to share British anechoic tiling technology with the Australians, so our clever cousins Down Under decided that their Defence Science and Technology Organisation should research and develop their own for the Collins-class submarine. This they managed quite successfully, and for some reason, the epoxy compound they used to glue them to their submarines seems to be far better; I’ve not yet seen a single photograph of Australian submarines missing any tiles in spite of the fact that their submarines deploy through far more diverse - therefore, far more wearing - maritime environments. To my knowledge, the Australians haven’t shared this secret with the UK. The Irony Strikes Back.
@@feliscorax that’s nice to know!
Investing is buying yourself a better future you don't have to work hard.
@Alex Stein What idea of investment one should be doing.
I'm a fan of crypto, I hold some few coins in my wallet.
@Goodson Thomas Nura Carvalho.
@Goodson Thomas fb name. 👆👆
+➊➌➍➏➐⓿➍➌➎➍➌
I thought this would be one of those channels that puts in a ton of filler to make the video longer and it is, but in the rare good way where that filler is also interesting information
Cruise ships are not ONLY white because of reflection, there are many pale/lighter colours that could be used that reflect sunlight more than sufficiently for the job. However, when such a ship is cleaned in strong sunlight water evaporates so quickly visible white streaks are left making it a much, much longer job to both clean the ship and clean the streaks from a coloured hull (you don't need to on a white hull, they're invisible). Cleaning a large coloured ship is an exponentially more time intensive task than cleaning a white one. Look at superyachts being cleaned, both white and non-white. The non-white ones take much longer and more staff to clean than white ones of the same size.
“Sir” “yes” “we crashed” “into what” “another sub” “where is it” “no idea sir” “then find out” “we can’t sir” “why not” “beca-“ *INSERT WINDOWS SHUTDOWN NOISES* Edit: Added new lines because some privileged roblox kid was crying about the detrimental issue that is the formatting of a satire youtube comment. Hope this pleases you Kaptain Kub.
LOL
Learn how to use new lines
@@luftkadettarchives6387 I guess that does not really solve your actual issue, does it? It's no shame to talk to teachers. Dominating others does not really solve mental stress..
@@thomas.leitner What? are you high or something?
@@thomas.leitner What has that got to do with anything?
@Not What You Think 2:27 Love the comedy ! 👍 New subscriber here with a question : Why are military helicopters so loud ? I would think a military helicopter would want to sneak up on the enemy. This would be an interesting video if you ever ran out of topics to cover.
I love it dude. I love it. The shots at Windows were so well placed. Hilarious. You'll prob never get around to reading this but if you do, how about a video on the military applicability of Vantablack...is there any? What a crazy uhh i think its still considered a color...
Thanks for your comment, Chris! Glad you enjoyed our video 😊 That is an interesting question indeed. We’ll look into it to see if there is opportunity to make a video about it 👍🏼
I used to have a copy of the audio tape from sonar control back in 1976 when a soviet submarine collided with the USS Voge. Once the collision alarms rang you could hear the announcement over the 1MC for anyone with a camera to lay to the weather decks to take photos. My friend collected pieces of the anechoic tiles, which we had not been told it had in sonar school at FLEASWTRACENPAC.
Slick!
3:16 Suffering from success
With modern technology its possible to produce rubber in nearly every color. For example you could color tyres in nearly every color and it only influeces the durability just a bit, not like back in the days when there was a big influence.
Learned a lot! And got a chuckle, too.
As a long time past user of NT, 2000 & XP I can appreciate your references.
Try dos
The ending was really amazing and unexpected!! 😂😂😂😂😂😂
Great facts, well presented, and with a pinch of humour. I approve ! Well done. 😎
Love the use of the Windows BSOD
That hides them in the background of sea and sky - makes them more difficult to notice from other ships and airplanes. However, they do not become invisible. The main object of this camouflage is to mask the silhouette of the ship, making identification and calculations of distance more difficult.
Brings a whole new meaning to Rolling Stones “paint it black”
As a submariner, I like how I had to go to KZhead to frigure out why the bottoms are red. Another cool fact about the tiles is how they need to resist and repel Cookie-Cutter Sharks, that would otherwise chew into them and allow for easier counter detection and corrosion of the hull.
Love the BSOD and it sound effects haha
I was really curious about how implementing Windows-based control software worked out! At 2:25 - 2:28 I choked on my coffee.
Mission Accomplished!
mission
Anotherone of those bluescreen jokes appear: *calm* You don't see the NotWhatYouThink picture in the bottom right corner anymore: *panic*
LOVE the blue screen of death pauses in this vid!
2:23 Well done - well done 👏👏👏
Why Submarine Black: **explaining 6 minutes straight** Why Cruiser Ship White: **literally 10 seconds with error** Whoa there. That's racishipt
Raships
eww get out of here raship
my name is Jeff
As someone who likes submarines (like, not have a slightest idea what diffrences, models etc) im okay with ship racism
What’s the error?
The Window's off sounds, and blue screen of death made me laugh, both times. Bravo!
The windows error screen kills me! Hahaha i love this channel 😭😍🤣🌋
Carbon in tyres is there to stop deterioration by UV light. The other reasons are minor.
BSOD, Windows jokes, and scientific references in description...... Subscription earned!
god damn that blue screen part gives me severe PTSD
Loved the windows blue screen of death. Had me in stitches.
OMG that was funny. The BSD at the very end had me rolling on the floor laughing. :)
0:54 thousands of man hours and millions of dollars to find out that the best color to camouflage yourself in water.... Is the color of water.
Yeah then you're like oh that wears out too quick
You do realize water is actually clear right? The blue you see in the ocean is the blue of the sky. Hugh... I don't think 'clear' paint would be a good idea at all... LOL But the ocean is lots of colors too depending on the weather, quality of sunlight and how much organic life (mostly algae) in it. Sometime the ocean looks green, grey, white with foam or waves with caps as air mixes into it. Even red sometime if a certain bacteria (or was it also an algae?) that thrives in water with very low oxygen levels. It's where the term 'Red Tide' came from. Same note... that water is lethal to all oxygen breathing creatures, including us, the fish or just about anything else. If our sky were to somehow turn yellow? Don't be surprised if our ocean looks like a sea of piss! lol And it's deep color? Go down deep enough even sunlight stops penetrating the depths of the ocean if you go far enough. So fill up a glass and add some salt. What color is it? That is the actual color of most of our ocean's salt water too, just depends what is in it and in what consecration that can change it's general color but it isn't the water itself.
@@jamesloll4601 tldr Water is blue. Pure water is a very pale blue. The ocean reflects the sky, but is also it's water content is intrinsically blue. What a weird thing to trigger a rant, particularly when incorrect. I'd suggest looking stuff up before dedicating such a text wall to nitpicking.
@@KappaKiller108 Then why the water I pour into my glass transparent? It should be blue like a cocktail or something, if I am following your logic..
@@shiveshsingh3169 en.wikipedia.org/wiki/Color_of_water
The windows just had me dead 🤣
love the windows hurmor, awesome
3:23 Okay but that happened because passive sonar is not used for that purpose. Passive sonar is for keeping an ear out for noises, and submarines dont make much noise, with or without the tiles. Active sonar is actually for 'looking around'
This rates a thumbs up just for the Windows jokes!
Correction, the Royal Navy were using tiles in the mid-seventies, their S Class Nuclear subs had them fitted. As submariner, I can also inform you that there are only two types of sea going vessel, Submarines and Targets !
Lizard
LOL... The Microsoft bit is hilarious. Of course, white tires show wear and are aesthetically unappealing. Another great post, NWYT!!
I'd like to add on to the fact that submarines were once surface vessels. Submarines were primarily surface ships because before nuclear technology, we were still stuck in the diesel engine era. But subs are meant to be electric because if they ran on diesel underwater, they would either be flooding the exhaust pipe and severely damaging the engines, or if not, giving away their location through gas emissions. So they run on battery, which can only power any vessel for so long, so boats use generators. These generators are what helps charge the batteries in the vessel and apply power throughout the whole ship at the same time so they can operate the motors that turn the screws (propellars), radar equipment, sonar equipment, maybe some kitchen stoves, and all the lights. This means subs need to *generate* electricity while running on *limited* electricity which is physically impossible. So a solution to this was to use 4 engines. The first two run on diesel and are used to input electricity into the generators. The second set of engines's the same except it runs on electricity stored within the batteries, these engines function the same way but are ONLY used when submerged. These limited batteries provide enough electricity to stay submerged for about 24 hours, and with that being said they *need* to surface or they'll just be out of power in the water. And thus has made 1940 and earlier submarine designs primarily surface vessels. Please note that this information isn't going to be spot on because most of my information was gathered off the internet since I'm a curious being with a fashion for submarines.