How do big ships float?

Ever wonder why ships don't just sink like a stone? Ever wondered how ships, even massive ones, are able to float on water? It all comes down to a simple but powerful concept: buoyancy. From Archimedes' Principle to the design of hulls and displacement theory, we will break down the physics that make it possible for ships to stay afloat.
00:00 INTRO
01:39 Gross Tonnage and Displacement
02:29 Archimedes Principle
03:29 Water Displacement
05:20 Why doesn’t a ship sink?
06:14 How different water conditions impact floatation
07:43 Stability of a ship - Gravity and Buoyancy
09:58 OUTRO
Oceanliner Designs explores the design, construction, engineering and operation of history’s greatest vessels- from Titanic to Queen Mary and from the Empress of Ireland to the Lusitania. Join maritime researcher and illustrator Michael Brady as he tells the stories behind some of history's most famous ocean liners and machines!
#science #ship #floatation #physics #engineering #ocean #technology #innovation #marine #education #learn #STEM #exploration #research #vessel #water #buoyancy #viralvideo #interestingfacts #curiosity #shipfloatation #science #mystery #maritime #engineering #navalarchitecture #oceanography #underwater #exploration #research #discover #technology #physics #marine #buoyancy #submarine #education #learn #engineeringexcellence #innovation
Freepik: London Bus - www.freepik.com/free-vector/r...

[@FlymanMS]

Ah yes, Empire State building, my favorite big ship.

[@klairithess8704]

Its mine too

[@mikiaization]

how do we know it doesn't float unless we try.

[@STUKA9113]

And the hindenburg

[@ThePsiclone]

@@mikiaization mathematics. Its buoyancy is much greater in air than water, that's why they built it on land. The very tip of it is incredibly buoyant and holds the entire thing up, hence why its fixed to the ground or it'd just float away...or something...

[@graeggede]

@@mikiaizationMath of course!

[@michaelimbesi2314]

Thank you for being basically the first youtuber to make a clear and accessible explanation of the difference between gross tonnage and displacement. And double thanks for explaining the role of water density!

[@gecko-sb1kp]

If only Popeye had explained that to Olive once or twice...

[@skenzyme81]

Bruce Ismay: [incredulously] But this ship can't FLOAT! Michael Brady: She's made of iron, sir! I assure you, she can... and she will. It is a mathematical certainty.

[@tomcurda4203]

Good one!!

[@MikeFinnell]

Mike Brady; The ocean is made of vegetable oil, I assure you she can...and she will.

[@toddkurzbard]

Captain Smith: But, Mr. Brady, this ship is sailing through a mixture of alcohol and gasoline!

[@Harpeia]

(also concrete ships float, more evidence of witchcraft)

[@lukasr.5839]

Reminds me of "Operation Petticoat" when Cpt. Shermann (Cary Grant) asked the engeneer who was repairing the submarine after it was bombed: "Can this boat go down?" - "Like a rock, sir!" :D

[@pknark]

Hey! It’s my friend Mike Brady from ocean liner designs!

[@rebralhunter6069]

I love how this gets posted every video now xD

[@barrysrcdump3557]

😴😴🥱🥱

[@Uniquely-Unoriginal]

@@rebralhunter6069 Same. The one time Mike actually said Michael (recently-ish), it threw me off enough that I had to start the video over because I missed the first few minutes, 😆

[@MckIdyl]

I don't have any friends who dress like that.

[@Sam-xt2gz]

Ah yes, the Jonathan Ferguson, Keeper of Firearms and Artillery at the Royal Armouries Museum in the UK which houses thousands of iconic weapons from throughout history, is spreading to other channels let's go xD

[@danlabok7117]

Thank you so much for explaining tonnage, how to measure displacement etc to us land locked folks.

[@MGower4465]

One thing nobody ever expected to float was the Bigfoot monster truck. But the tires hold such a volume of air the truck can actually float. Bigfoot was fitted with a second tire at each corner for stability and actually raced a paddlewheeler on the Mississippi River. The boat won. But it was a very poor sport about it and refused a rematch on land.

[@JLowe2013]

Always glad to see our friend Mike Brady from Oceanliner Designs!

[@williamdunklin]

Great video! I'd like to see a further explanation of hull shapes - particularly the difference between the flat bottom of ocean liners vs the V shape bottoms of sailing ships vs the sword-like keel of smaller sailing vessels.

[@MisterOcclusion]

I’ve been browsing many of your videos, and this is the first time that I’ve seen an explanation of displacement versus gross tonnage. Up till now I had thought them interchangeable. Thanks for the disambiguation.

[@BPond7]

I was of the same thinking. Love this channel!

[@geecroe-vu3xk]

Tis a good day when my friend, Mike Brady, from Oceanliner Designs uploads

[@BobbyBobby-wi7kv]

When I was a child my great-grandmother would tell stories about coming over from the old country aboard the empire state building , they were cramped and famished for food but happy to arrive into the liberty bell....

[@bigbossimmotal]

That must have been a beautiful view looking out the windows on the side that was in the water though.

[@BobbyBobby-wi7kv]

@offroadguy7772 Baltimore

[@bigbossimmotal]

@offroadguy7772 The place she lived before moving to the new country I'm guessing. lol

[@KSparks80]

Largest glass-bottom boat ever! Wonder if they charged an extra fee for the underside windowed "sightseeing" cabins? lol

[@MckIdyl]

Pilgrims didn't land on Plymouth Rock -- Plymouth Rock landed on them.

[@lenlevine7146]

Wonderful job Mike. I like the generic videos a lot because they help to understand the ones on specific ships. A good mix is great. Titanic, tho, enough already. Suggest a video on how Francis Gibbs designed SS United States to avoid risk of fire. THANKS

[@bigbossimmotal]

I second THAT suggestion. I would watch ANYTHING on the SS United States.

[@miloanderson4359]

For all us Americans, the queen Mary 2 is a little over 3 football fields long or roughly 0.75 metric freedoms long. As an American I also wish we measured everything in metric.

[@WALTERBROADDUS]

Nobody wants a .113 Kg. burger with Cheese.🍔

[@unclerojelio6320]

How many giraffes is that?

[@kristoffer3000]

@@WALTERBROADDUS You mean a 110g burger with cheese?

[@ShadowDragon8685]

@@kristoffer3000 damn metrication, that's how they short you three grams of beef!

[@kristoffer3000]

@@ShadowDragon8685 Is the quarter pounder even a quarter pound of beef right now? lol

[@thirstyCactus]

Right, so if a ship takes on water, it's displacement weight goes up, so the ship must drop to displace that same amount of water. That's a pretty clear way of thinking about it. Thanks, Mike!

[@nthgth]

Yup -- and when a ship is sinking, it's simply positive feedback of that very effect

[@smoceany9478]

it is now my supervillian plan to replace the worlds oceans with oil

[@JoeJaJoeJoe]

USA has entered the chat

[@pills-]

Better yet, put air pipes at the bottom and turn the ocean into a giant jacuzzi!

[@richardlewis4288]

Thank you! Finally an explanation I understand!!!!!!

[@Lesnz2009]

I learnt that way back when I was at school as one of my maths teachers was a boatie and he decided to teach us how boats and ships float to explain Archimedes principle. Cool that you were able to it much like he did in a straightforward manner. Thanks Mike

[@haleighwright9177]

I think it would be neat to see you react to some of the videos of ships in the North Sea, those are some wicked and scary conditions.

[@XxThePlaylistxX]

That sounds like a great video idea, reacting to different sea states and how different ships respond to them.

[@eladrevocnayrb0807]

Capital idea!

[@MrToaster747]

Thanks a lot for your perfectly understandable explanation!!!! Great video as always Mike It's always pure joy to watch your videos I just love it ❤

[@jimmcmeen761]

Man your videos are bangers! You should be proud of your worked. I remember when you were around 100k subscribers. Keep it up man!

[@bripez]

This just made me look at how many subscribers he has and holy shit, I started watching at 60k! I’m weirdly proud of this guy ive never met 😂

[@kallekas8551]

Mike Brady…Time Traveler…👍

[@nozrep]

that is fascinating. Did not know any of that! And yah I am one of them people watching a lot ship videos recently in the wake of Francis Scott Key Bridge, whereas I would not normally watch educational ship oriented videos.

[@NerothLoD]

Pretty sure a bus would float if it was made watertight. (I'm not 100% certain, since I'm not smart enough to do the maths on that.) Cars don't sick like rocks when they go into water. They only sink once the interior has filled up sufficiently to counteract buoyancy. Also, consider that there already exists an ocean on earth that is less dense than water. The atmosphere. It's the same principle for things like a balloon or blimp, only they have to alter the properties of the lifting gas (such as heating it), or use a fill gas other than air, since that would just be the same density as the surrounding atmosphere. Just some things I thought it might be interesting to note. Great video as always. :)

[@joeporkka2047]

Doing a little digging I found the dimensions of a double decker bus. 11 meters long. 2.6 meters wide. 4.42 meters high. Give or a take a bit because a bus isn't quite just a block. I also found that a bus weighs around 18 tonnes. Given those dimensions, the bus volume is 126,000 liters. Conveniently, 1 liter of water is about 1kg. So a bus volume of water weighs 126,000kg - or 126 tonnes. A double decker bus would easily float if it was sealed up to not allow any water to enter. foi.tfl.gov.uk/FOI-1433-1920/Bus%20Vehicle%20Specification%20v1.1%20May%202019.pdf www.london.gov.uk/who-we-are/what-london-assembly-does/questions-mayor/find-an-answer/new-bus-london-vehicle-weight-1

[@soyevquirsefron990]

Re ocean of air, yes while watching this i was thinking of trying to push an inflated ball underwater, ships work the same way except the ball is made out of steel but it still floats. In fact a steel ball would float in the air if you put enough helium in it… like a dirigible! And there’s the Hindenburg in the size comparison chart. Its all the same physics

[@aaronkcmo]

@@soyevquirsefron990 you'd never get a steel vessel to float in air, no matter how much helium or hydrogen you add. the weight of the vessel would never be overcome by the negative buoyancy of the lighter than air fluid.

[@nadarith1044]

@@aaronkcmo It would if it was big enough, volume grows faster than surface area.

[@aaronkcmo]

@nadarith1044 in order to have enough volume the steel vessel would not be able to support its own weight. That's the problem

[@jajssblue]

I'd love a video discussing the efficiency of shipping in comparison to other means and also through time. It would be interesting to know if Edwardians had a lower per person emissions footprint compared to a modern person on a 787 Dreamliner.

[@KSparks80]

From 1901 to 1910 it took an average of 8 days to sail from Liverpool to New York. I'd be willing to burn a bunch of fossils to do it in 6/7 hours in a Dreamliner! lol

[@JJsOriginals]

Ahh, my friend Mike Brady from Oceanliner Designs.

[@kallekas8551]

Oh! Mike Brady from Oceanliner Designs…👍

[@MrZzyzxx]

Love this channel - especially love this kind of seemingly munbdane info - tired, tired, tired of more and supposedly necessary info on Titanic...........we've beat that 125 year old subject to death. -- stay healthy, Mike, and G'Day !

[@MrArby343]

Mike Brady Our Friend 🎉

[@marathonrunner2590]

Mr. Brady, I thoroughly enjoy your videos. Your explanations and articulate delivery combine to deliver a great deal of information in a very approachable and easily understandable fashion. I wish that many/most of my teachers in public school/college/graduate school had your expertise in sharing information.

[@NinStardust]

Found this channel three days ago and have been addicted ever since! Never knew I could be so fascinated by ships or ocean liners, but here I am, hanging on your every word! Love the stories, the history and the science. Thank you for awakening a new interest and making it so enjoyable, understandable and addictive! 🥰 ⛴️ 🚢 🛳️

[@thelonelyturkey7902]

Thank you for another great video! Will send this to my friend who loves science stuff.

[@Jesusiscominglive777]

Thanks for the great video to help me understand this more❤

[@AulusClaudiusNero]

Hey Mike, maybe you could do one on why wooden ships sink even though their individual parts often float when they break apart. I have a pretty good hypothesis as to why, but your explanations are always top notch and knowing is better than guessing.

[@joshuaquintana148]

Absolutely phenomenal Video. Love the quality, mate!

[@lawrencefleck1117]

Looking good today!

[@SpiceOctopus]

Depending on what you define is a ship, there would be a currently active vessel with similar size to the Seawise Giant. The Prelude FLNG displaces 600k tonnes, with a length of 488m, beam of 74m, and absolutely ridiculous height of 105m. I suppose it doesn't quite count since it doesn't drive under its own power, though I does have some propulsion for positioning.

[@paulaharrisbaca4851]

I love how simple you make things like how iron/steel ships don't sink immediately. I remember you saying that Brunei's Great Eastern was mocked by the "smart people" in the social media of the day said it would immediately sink upon launching...

[@rickh8380]

Thanks Mike. I learn new things I never knew before every time I watch your content. One of my favorite channels. I always look forward to new videos you post. Cheers from The States.

[@ReallyBruh1]

I remember when I was younger I was always asking myself “how do ships float?” And the answers finally been answered. Thx Brady! 🚢❤

[@Shazprime]

Thanks for the lovely video, Mike. Cheers from Connecticut, USA. Love you, your way of presenting yourself and your content, your style, and of course most of all your videos are such a delight. Thank you so much! 😊

[@Walker_TR2]

It's always a good day when my friend, Mike Brady from Oceanliner Designs uploads another banger video. Keep up the good work!

[@truthtoldicu]

Another fantastic Vlog thank you for your hard work and time you're one of my top 10 subscription

[@Robert-kv7gb]

Love it, just what I needed to take my mind off things. Thank you 😊

[@PaladinCasdin]

There was a video posted the other day on one of Simon Whistler's channels (I think it was Side Projects?) that involved the Titanic. Just about every 'fact' in the video was wrong, and the entire comment section was full of 'Where's our friend Mike to correct all this?' Literally every second comment. Videos like this show why - concise, factual, with excellent delivery. Thanks Mike.

[@ahorton6786]

Interesting stuff, thanks for explaining to us non shipping folk.

[@pedrofayolle]

One detail that's often overlooked when explaining buoyancy is *why* water (or any fluid) exerts an upward force at all. If you pause to think about it you'll see it's not obvious. The explanation has to do with the pressure difference that occurs when a column of fluid weights on itself, the bottom of the fluid will have a higher pressure than the top, and that pressure difference is what's creating the upward force. Also, for buoyancy to exist you need gravity. If you had a big tank of water floating in outer space where there's no gravity and took a model boat that would perfectly float on Earth, then placed it on the surface of the water and gave it a little push inward, then the boat would go through the water like it's air (although with more friction), there would be no buoyancy because there would be no gravity to create a pressure difference on the body of water.

[@stevenkarnisky411]

Excellent presentation, Mr. Brady!

[@Tina-ts9wv]

Recently subbed and this channel keeps getting better

[@ericlavorel7225]

Dear Mike, thank you so much for all your vids. To go further with this one, with ship's stability, with new hull shapes, I suggest to take a look at what is called "parametric roll", a very strange phenomenon which has caused serious damages to container ships and lots of containers losses at sea.

[@kwakas4ever]

Very informative - thank you!

[@waynepatton718]

Fantastic explanation thank You

[@bandulad7695]

Awesome informative video as always!

[@kellyalvarado6533]

Thanks for all your hard work.

[@GearzMonkey]

Great video. Would've loved a more in depth mathematics and physics, especially relating to the Force of Buoyancy and how the position of CoG relative to the CoB

[@jammiedodger7040]

We need to bring back ocean liners.

[@wilfredburbank6701]

Thank you for such interesting lessons on ocean-ing.

[@mikestrohm3271]

I was an officer on cruise ships and an American passenger - when we were alongside in the Bahamas - asked me about how the ship was supported alongside. I was a tad confused but as I spoke with him some more I realised that he thought that the ship rested on the bottom when in harbour. The crux of this conversation was that he believed a ship was like an aircraft and that as we moved forward the hull imparted lift (like the wings of an aeroplane) which allowed the ship to navigate in deeper water. When we came into harbour he thought that as the ship slowed it would gradually lose lift and then sink to settle on the bottom alongside the pier. When I asked him how he thought his belief worked when we were at anchor, his 'theory' was that the anchor chains were stiff and that they acted like legs which kept the ship on the surface! To put this into context, when cruise passengers join a ship for a cruise they pass through a special depository warehouse before boarding which is where they leave their brains behind for the duration of the cruise.

[@kellyalvarado6533]

😂😅 As a frequent cruise passenger, I resent that. Also, as frequent cruise passenger who has seen w a y too many adults act like children once they have a drink 🍸 or 2, I agree with that! 😅😂 Once worked with a lady who thought "shipping lanes" meant there were the equivalent of railroad tracks across the ocean floor and that ships were essentially like trains - and THAT'S how they managed to find their ports. 😢😢 I kid you not.

[@gbcb8853]

His passport gave him a waiver from the special repository.

[@mikestrohm3271]

@@kellyalvarado6533 I also spoke with a woman who thought the window washing 'robots' that passed down each side of the ship were part of a 'ship wash' - like a car wash - I imagined she thought the Captain moored up to it, stuffed a dollar in the slot then dived back in the bridge before the wash started.

[@kellyalvarado6533]

@@mikestrohm3271 😄🙂😂😊 How do they make it through life??

[@mikestrohm3271]

@@kellyalvarado6533 I have no idea!

[@JefferyHall-ct2tr]

Hello Mike Brady, My Friend! FASCINATING video! What interests me, is how these modern ships with TOWERING superstructures don't just tip over and capsize! My assumption is that these more modern ships have a much wider beam than the older ones. That, and designing to use the lightest materials possible, the higher up on the ship it is. I would also think they keeps LOTS of fuel right down in the very bottom of the ship. Whatever the reason, it seems like a miracle sometimes that these ships don't just capsize!

[@brianhamel493]

this is what I learned today! love these lessons

[@MultiJulia1980]

Thank you, Mike! My children are school students, and they also study English. So this video I showed to them. Both because of physics, and also because of your perfect speech. Thank you!

[@coreymulvey6141]

Something tells me even archimedes never imagined such gargantuan vessels sailing the ocean…

[@rkolarsky]

A great video, Mike, as always! Yes, the density of the water affects buoyancy in a major way. Imagine a sudden release of natural gas into the water column. There are examples of semisubmersible drilling rigs that tilted or nearly sank because one or more of their legs were immersed in a bubble of gas that somehow escaped from the wellbore are was not caught by the blowout preventer. Methane bubbles in water reduce water density, therefore reduce its buyoancy capacity.

[@danielintheantipodes6741]

Great information! Achimedes was amazing!

[@TheHylianBatman]

As someone who didn't particularly study math, this video is a welcome one! I feel like I understand more of the engineering side now; now it's time to start reading! Thanks, Mike!

[@josedegara8598]

I really like your documentaries,,,very precise,,,very educational

[@jonesey1981]

It’s our friend Mike Brady from ocean liner designs!

[@whiplash212345]

another awesome video from my friend mike brady from oceanliner designs!

[@IntrepidMilo]

This is bringing back memories of ship stability and construction classes, as well as phsyics classes. In fact this is being taught better than some of my instructors taught at the nautical institue I attended.

[@Mountain-Man-3000]

I think "How do they not tip over?" is the real question.

[@jbepsilon]

Indeed. The basic math behind stability is easy enough to understand, but still I find it very unintuitive how something like a cruise ship doesn't keel over in the slightest gust.

[@crumbdinger]

There are several videos here on ships that list & why (basically height v. width) but maybe start with “when engineering goes wrong” or, if you want to be sad forever, watch his video on the Sewol ferry tragedy

[@emcewen]

Great video and explanation.

[@NFS_Challenger54]

If I didn't know any better, Mike, I'd say you work, design, and outline ships for a living, while doing this as a side job or even a hobby. Great video, man.

[@LazarusProductions2]

These vessels show just how far marine technology has come in the last 100 years. Amazing breakdown. Keep up the amazing work!

[@SGTSnakeUSMC]

Great explanation!

[@MGower4465]

How do giant ships float? Carefully.

[@whelanvidswhelanvids1500]

I’m a pilot and relate well to some of the concepts of floating etc but I hate the water. For some reason I’m fascinated by marine engineering. Thanks for the content

[@remb9614]

My pal MB! Good to see you friend!

[@lloydknighten5071]

Mike Brady, great explanation of how ships float. I always was astounded as how the 70,000 ton YAMATO ever floated.

[@alexibarra6618]

Interesting how this question just randomly crossed my mind and first video I find is from yesterday, nioce.

[@robertmack7116]

In some strange way, you do feel like a friend! I enjoy your content.

[@mrb.5610]

Did a bit of Canadian canoeing at one time - and the 'hull' design or shape certainly made a difference - especially when you 'edged' or leaned them over onto their sides. Some definitely didn't want to do this - but conversely would flip and capsize with a comparatively small increase in the tipping angle - others would seem less stable - i.e would take less to roll - but were a lot more controllable near that tipping point - if that makes sense !

[@ericlew9992]

Not previously understanding how that all worked, that was fascinating

[@user-sk6ct7nj3f]

hi mike im Joshua so i had a bad day at school and your video helps me out and i love your vidios

[@fordson51]

Greatest description of a what a ship is came from my brother. A ship is essentially a bathtub with an engine attached. Why do you think sailers use to refer to them tubs?

[@user-of5lw4oy3c]

Very informative.

[@scottlewisparsons9551]

Thank you Mike for another very interesting video. Perhaps a video about Sam Plimsoll might be a good subject for a video and also why gross tonnage which is volume is expressed as tonnage. While I had been taught about Plimsoll in primary school I had never even considered that water density would be much different between warmer and cooler areas of the earth. All the best from Sydney.

[@AdamJRichardson]

Fascinating! First time I've discovered your channel. Your discussion on CG and CB makes me think of a recent video by Smarter Everyday where Destin vists NASA's Neutral Buoyancy lab. Astronauts doing training in it have to go through a set-up procedure each time that's pretty cool to perfectly align their CG and CB in all axes so that they pivot in the water just like in zero gravity.

[@anitaovenden9431]

I don't even like boats, they scare me but for some reason everytime your videos pop up, I am like 'go on then Mike Brady from Oceanliner designers tell me about xxx'. These are great videos mate, keep it up.

[@duchessstudioband7896]

Mike and his channel are my constant companions on my graveyard shift job. Lol. Yes,a good Maritime disaster helps to pass the time between customers, but also educate. So, thanks Mike, or as this Croat woman would say , Dubro, Dubro Micha.

[@trishcook1857]

Thank you Mike. That was very interesting and informative

[@TealCheetah]

It's our friend, Mike Brady!

[@FrostWazowski]

We all have a favorite friend ... my favorite friend is my friend Mike Brady from Oceanliner Designs. No contest.

[@Shipspotting_Vietnam]

Nice video!!!

[@BenBootKHTwo]

They stay afloat as long as the people running them don’t mess up.

[@bentboybbz]

Sometimes they still float, as long as the people running them don't smash any holes too large into their hull

[@karroq]

My roommate asked me last night why steel is better than wood, and despite it seeming obvious, I couldn't come up with a solid answer. Could be a good video topic.

[@milesking7697]

Mike I absolutely love your channel. However, I do have a request. Can you do a video about the Queen Mary and the Curacao. It is such a crazy moment that I feel is never talked about as much in regard to both the Royal Navy and the Queen Mary’s history.

[@puterboy2]

When this month are we gonna get the next update to Grand Voyage?

[@TimRobertsen]

- How do ships float? - Luckily, water is dense

[@SchneiderGeorge]

I know you went to great pains to explain all this, but I must say I'm grateful that those people who design and build ships understood what you were saying. I was completely lost!

[@biosparkles9442]

Mike, have you been to see the Titanic exhibition currently at the Melbourne Museum?

[@stuff___idontknow2610]

I had a much easier time learning from this video than sitting in a classroom for an hour listening to my boring school teachers