What is the BULBOUS BOW for?
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- Опубліковано 6 жов 2024
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What is the protrusion commonly found of the bow of a ship actually for?
The Bulbous Bow is built into the hull of most modern ships, and besides from looking slightly odd it actually serves a functions. This video will answer the question: What is the bulbous bow for?
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The bow wave you want to mitigate will vary depending upon the ships speed, sea state and wind. A fixed bulb can only be optimised for a single condition and in other conditions will actually be harmful. In any case, the mitigation will only be partial at best, so the benefits might be limited. For a vessel almost always travelling at a constant speed this might be acceptable. But for a vessel constantly changing speed and course, example a sailing ship or warship the benefits might simply be too small to justify the costs. For a small yacht the benefit might be very small ( the speed is low, the bow wave very small and the fuel is free and who really cares if sometimes you might go 0.1 knots faster ).
An ideal bulb would be able to change it's shape to automatically adapt to the conditions, just like aircraft have swing wings. However making a 10?? ton shape shifting bulb might be way beyond practice, although perhaps this would be a good project for a naval design student somewhere.
Thanks David. You are right, it would be a great project for a naval architect student - and I know shipping companies would buy it if it would save fuel!
I would have thought that a bulb that can be made to move it's position forwards and aft depending on ship speed wouldn't be beyond the limits of engineering. Wouldn't that widen the window of speeds for which the anti-phase wave could be set up?
Moving the bulb alone, might not be enough to help. It might need to change size/shape as well. The key problem would be if the wider window of speeds gives useful savings at speeds actually commonly used by the ship.
david james As I understand, these bulbous bows are used mainly on large, ocean traversing cargo vessels, which do travel at mostly constant speeds at sea. Their main speed changes happen near land, and not where they spend most of their time moving through the water, the ocean.
david james you can still try to aim at an optimal condition. The cost is marginal on the scale of large boats being built, and the drag is mostly affected by high speeds, so you can bet that optimizing the bulb for medium-high speeds for bigger ships is a sure way to go.
I believe it’s for mating reasons with the female ships
all ships are female ...
John Clayden did you just assume all boats gender
John Clayden Not entirely true. The Kaiser wanted some of the German ships to have male pronouns.
Jake Fejer All ships are female.
Female's can wear strap on's though...…..
i really like these kind of videos, no bullshitting around, informative and in only 4 minutes i know what i wanted to know when i clicked on the video
And no annoying background music
I found it interesting . Having watched ships and this bulbous bow and not understanding what's its use . And now we know . I liken it to a form of leading edge on an aircraft wing .
My father, who was a navy man, always told me that this behaviour was found by accident. The first was build for sonar and it created a possitive increase of speed
I read somewhere that they discovered this when they put rams on the front of early metal war ships. When a ram fell off, the ship was slower and someone went 'ah-ha!'.
Your Father was right. On Warships they are Sonar domes.
i immediately started chanting sonar when the video asked what the bulge was for, only now i learned it also on very specific occasions and circumstances helps with the waves.
@@Nibby12sorry but no. The bulbous bow predates sonar by quite a bit. The reason that it's used for sonar on warships is simply that the location of the bulbous bow is exactly where you'd need to put a forward-sweeping sonar setup, and since they already had that protrusion, they just put it inside of the bulbous bow.
Now you can tell your dad that it's actually the opposite, and he can learn something new 👍
“Is that a bulbous bow on your hull or are you happy to see me?”
Sorry I was just waving.
?
Lmfaoo
Lol
I just like the word "BULBOUS".
I was part of the commissioning crew of the USS Ronald Reagan CVN 76. We had tee shirts made that read, “ I’m Not Fat. It’s My Bulbous Bow.”
*I* too was on the commissioning crew of the USS Ronald Reagan CVN 76 and I am calling you out on your bovine excrement.
@@bollockjohnson3706 lol
I was also one of the dry dock crew of Ms Rotterdam I have pictures of bulbuos bow but on that time I don't what is the used of that bulb
Shite yank banter
@@i_know_youre_right_but Seethe. Cope.
I am teacher and I can tell you you did a great job, no flashy words but the physics was very clear.Thanks
Thanks Physics_rabbi. I hoped it would would come across clear.
Don't eschew "flashy words". Learn instead.
Not an English teacher I presume.
@@CasualNavigation Clearly?
wholeNwon when teaching a new concept it’s generally not a good idea to introduce new terms. it’s better to let the students grasp the concept before telling them how to put the concept into words
Canceling the wave out, also reduces turbulence and cavitation on the rear propulsion
Thanks i Just wanted a short 0answer and Not 4 Minutes of blabla
Yoooooooo
Really? For a typical freighter i would have thought that any effect would be dissipated long before it reached the stern of the ship. And no freighter should ever be using it's propellers close to cavitation speed.
There you go! It took you 10 seconds to explain what the video tried to do in 4+ minutes Thank you!
Yes
I love how the internet have all the answers to those random questions we ask ourselves about lol
Yeah!
Look up cow aerodynamics some time.
You won't regret it.
And all the questions we don’t ask ourselves
@@doughesson down the rabbit hole i go lol
I'm going to use the information in this video at parties. As an icebreaker.
Made me laugh out loud
Me too! (LOL, I mean)
Ironically icebreakers do not use bulbous bows as far as I know. Might want to try a spoonshaped bow for maximum effects. xD
That’s freaking horrible!
I LOVE IT!
Lol.. I was already thinking about it !!😂😂
There is actually one more very important reason for the bulbous bow along with the wave canceling effect!
A ship which moves considerably slow without the bulbous bow will create 70% more air bubbles than one with a bulbous bow, as well as the lack of wave counteracting effect, moreover the bubbles created by traditional bow gets push to the bottom of the hull which causes a loss of water pressure underneath the hull inturns less force pushing against hull, and decrease buoyancy, therefore the ship will sit lower in the water and create more drag and less hullage capability.
on the other hand ships with bulbous bow, when the bow pushes against the water, it creates fewer air bubbles and the bubbles are mostly displaced to the side of hull, therefore, the hull will maintain its water displacement, less drag and what's even better is the air bubbles get push to the side of the hull making it less drag from the side of the hull resulting better fuel economy!
Did you just make that up? 😃
JK it was a very informative comment.
Lol
@@aberamagold7509In fact I tried it out on a few scaled models and in CAD fluid test and both supports this...
I don’t believe you
Sounds some some brilliant mark Twain shit I like to make up. Sounds good, but is it really true?
I consider anyone with a British accent to be an expert.
Thanks Manoj. As long as we all keep learning, that's the main thing
Mr Bean?
Manoj Philip They feel that way as well.
I'm British with a British accent and I'm an expert in fuck all!!!
Not me. All I gotta say is, name a ship disaster, then ask, who built her.
0:42 ''Let's consider this vessel'' Me: TITANIC!
CRS Ikr it's clearly her..
It's so easy to see
CRS It could of easily been the Olympic. The Olympic classes all look the same.
Me too hahahhh
Dylan Hultman correctly, could HAVE been, or could’ve been. Could “Of “ been, is non- sensical. Just sayin’.
1:37 "If we think back to mathematics."
Me: * Vietnam-style flashbacks begin *
😂
Never searched for anything revolving ships. But I still clicked
That's because Google knows what you want to see before you do.
That’s actually pretty genius. “Hey let’s make a second set of waves ahead of the first that will cancel each other out”
Is the effectiveness a function of speed?
@@DrWhom yes
Same principle behind noise cancelation
I used the wave to destroy the wave
bow's passive cancelation. Not to be confused with Bose active cancelation.
also it only has to cancel the wave along the hull, I mean somewhere out there, there might be a bigger wake.
You know I've always wondered about the bump on the bow of a ship but never seemed to research it honestly.
Stumbled across this video and honestly learned about it ha! Simplistic explanation and well laid out video makes it super easy to watch. Well done sir
Thanks killerta87
Now I understand what the hull is going on!
Thank you!
Clever😂
A lot of this I already knew because I was a US Navy sailor but I’m still learning a lot from these videos, I’m glad I bumped into this channel. Well done.
I woke up with a bulbous bow this morning.
Nice
Nailed it
I hope you weren't put in a dry dock.
what was her name?
@@woofowl2408 wonder what that
ol' Night Mate wuz doin'???
Nonsense. It was designed by Airfix so you have somewhere to hold the model when you paint it, as any fule kno.
Haha
🤣😂
Lmao
And then the shipbuilders were like "oh heck, our ship isn't accurate to the model" and changed it
Thanks
When I was younger, my dad told me it was for ramming sharks
Lmao that made me laugh
Happy younger life...
Right. But it renders useless, when they already began to form a sharknado.
d3m3n70r lmao! Not the f-in sharknado!
It started off with only female sharks but eventually it changed to anything in the water and nothing was safe from then on...
Excellent explanation. Thank you.
Thanks William! Glad you liked it.
“This first vessel” is clearly the Titantic
Full Speed Ahead!
Or...perhaps...one of her sister ships...which gave decades of service. Mmm?
@@patagualianmostly7437 Titanic
@@angelvillegas9604 nope not Titanic, there is no Jack and Kate on the top deck on the front...
@@ICUinthedark Jack's not real
Great explanation! I used to provide water taxi service to ship's agents servicing the cruise ship industry here in Maine. Twenty-five years ago these cruise ships generated huge waves in their wake. Today a 1,000' cruise ship produces a wake smaller than that produced by a 36' lobster boat largely due to these bulbs. And speaking of lobster boats, a local fisherman took a clue from the cruise ship industry and added a fiberglass bulb to the bow of his 45' boat. I've photographed it several times while the boat was tied up to the dock but have never had the chance to ask the owner if it has worked to reduce fuel consumption.
This is called "destructive interference"
jon doe The phenomenon is called destructive interference it is an important phenomenon in the physics of waves.It is taught at 1 year college and senior classes in schools
jon doe
Thats what it's called itself, but the effect it has is callef destructive interference
jon doe correction "gone to" instead of went to
Sounds like Tump's foreign policies. 😀
I would have guessed for two reason :
1. It's act like a bumper, to prevent the hull got damaged if it hit something
2. As sacrificial part, so it get eroded faster by the water, than the original bow section
Thanks that I found this video 😅
i always thought it was for ramming in military applications
UA-cam: Hey you, we see you like to watch sitcom clips and funny animal videos. Now listen to this British guy explain the mechanics of cruise ships.
Me: *ok*
I’m here a year after 😂😂
You too?
When I was young, I thought it was a sonar dome. Then I realized its true purpose. The first ship to have the bulbous bow was the S.S. Jimmy Durante.
Lol
Hm like a beluga whale :)
It’s used for making baby tug boats that will someday grow up to be ships.
Tugs never get anywhere, they just hang-around their mother's harbor. you have to cleave some water to be a ship.
🤣
To differentiate male ships from females..
there are only female ships cause if a male ship gets penetrated. Its gay
There’s only two genders
All ships are female.
@@MrEazyE357 why?
And gay ships ? How to differentiate them ?
I live in the middle of the desert, why am I watching this at 1am...
Happy life??
All this time I thought it was for crushing ice. I learnt something new today. Thank you
There are some for crushing Ice!
The have bigger, angled fronts to push the ships above the ice, then the weight breaks the ice!
@@DeathByLego dam! that was what i was going to say, ice breakers are very costly to run due to the flat hulls and the drag.
@@thatdude101ish have you seen the biggest Russian one?! It’s an absolute monster.
I've seen those many times and always wondered what they were for. I've heard anywhere from a forward weight to help hold the bow down, to breaking the waves before the bow has to hit them, but this is the first time I've heard about the destructive interference design, how cool!
This is great thank you. I love learning about anything! I used to go out with a girl whose father was a naval architect. He made millions because he created a piece of software that predicted the rise in water levels. He wrote it in C+ years ago. He was actually an arse outside of that. When I started seeing her he Contacted my university to see if I really worked their and completed a PhD there. As I was really well known, and this is a very specialist small university, which only has PhDs or Masters, HR contacted me, laughing about it. He pretended that his company was offering me a job, so he broke every privacy rule around. He thought he was the only person in the world with a PhD from a world top ranked university.
You got a PhD?is English not your first language?
I've just assumed forever that it was to add buoyancy to an area of the hull with the least. A great explanation.
... and by adding buoyancy it helps a ship do what it is meant to do - namely carry things.
Wonderful explanation, in 4mins I feel like a smarter man!
Thanks Scott. Glad you liked it.
Is that not the whole reason for You Tube existing?
Just a shame more don't use it.... after watching those of Jay Leno.
Dear-oh-Dear. The billions wasted on education.
It could actually fund a social health care programme........
The bulbs were from WW2 submarines for their sonars, it just worked out for great unexpected advantages other than for sonars. Then so, the bulb design went to ship bows....thanks to the WW2 submarine.
wave haven A lot of ships in at least the US Navy still use the bulbous bow to house their sonar
A lot of merchant ships do to. It is a nice empty space right in the bow so is ideal for sonar
@@CasualNavigation are you crazy or do you not even know merchant vessels have no sonar. The bulb is a void with nothing in it. In some vessels it is common to the forepeak..commercial ships have a transducer for the depth sounder. It's a little bigger than a hockey puck and sits up forward.
I was actually wondering this exact thing (about subs and sonar) I was wondering if it was an accidental discovery. 😁 good stuff. :)
The Yamato had it too IIRC.
I was told that they were small rooms for radar sensors or something, I don't remember where I learnt that but this makes a whole lot more sense, you explained it very clearly.
It true for the Arleigh Burke Class Destroyer and other military ship
We can add one more function to the bulbous bow: to get stuck inside sand and prevent ship from moving
Its there for the purpose of reducing drag and streamlining hydrodynamics. Plus it can alsi be used to RAM the hell those megalodon blocking the way
Things that we spend whole day in studying, learnt in 4 minutes. Thanks!
*I have wondered this for years. I suspected it had to do with waves but how exactly I didn't know. Thanks for making this video.*
0:11 is a Swedish/Estionian company and it cruises from Stockholm to Tallin.
Also Finland-Eesti and Finland-Sweden
I love when UA-cam answers all my questions at 2am.
It sounds a bit weird to call it drag because we usually call it resistance. But i think it's to make the explanation understandable to those who didn't know Naval Architect. Great job!
Resistance is normally a force directly opposing something whereas drag is friction along the sides
I had no idea I needed to know this but I’m glad I now do!!
Brilliant. Short, neat , clear and interesting. Thank you.
Your videos are always compelling. Thanks.
I went on exchange about 10 years ago... Lived a while in Finland... Traveled in Silja Line and Tallink, to Tallin and Stockholm... And also visited the Vasa Museum... I loved ships but never imagined I would end up studying naval Architecture as now ❤️
I am always thinking that it serves as a water break. Thank you for educating me
Nice job demonstrating this on an Olympic Class Liner from the White Star Line! If they only had this technology and knowledge over a hundred years ago that they do now (that and also safety equipment)?
Thanks Zach. Glad you liked it!
Zach LaFleur My first thought was “Is this the titanic?”
In which case. If Thomas Andrews can get the length of the bulb correct. Not only would Olympic, Titanic and Britannic be even more fuel efficient. The reduction of drag could raise their top speed by a few knots. Whether it would be as fast as the Lusitania and Mauritania, i don't know. But it would be close. Hell it would be even a great selling point for passengers.
@@ph89787 'cause what would passengers care about? Mostly luxury and speed. They would even retain the Blue Riband if they had bulbous bows for how many years, probably up to the inter-war period.
The increase in speed due to the reduced drag would only mean the RMS Titanic would've hit the iceberg at a higher speed and possibly done more damage so it might've sunk faster.
Subscribed to your channel recently. Really interesting to learn new things about an area that I’ve not really thought about at all before. Thanks
This video fulfills my daily quota for new things I learn. Thanks.
US aircraft carriers are designed with that bow piece for the same reason, even though being nuclear powered pretty much negates the need to conserve fuel for the vessel's propulsion.
Of I am not mistaken, it was the Japanese Imperial Navy that invented this for the Yamato and other fast huge battleships.
@@danepatterson8107 You are mistaken. While bulbous bow designs were developed for IJN ships; according to en.wikipedia.org/wiki/Bulbous_bow, _the bulbous bow concept is credited to David W. Taylor, a naval architect who served as Chief Constructor of the USN during WW1, and who used the concept (known as a bulbous forefoot) in his design of the USS Delaware, which entered service in 1910._
“As you can see, they’re all different sizes” that’s what she said.
Lol
At least it's not called a "bulbous member".
I was about to give you a like, but I saw that you have 69 so I’ll leave it alone.
Strange this should pop up now, but I think it's for getting stuck in canals.
🤣🤣🤣
I didn't know what that was, nor that this was a ship video, so here I was staring at the thumbnail having an existential crisis as my brain tries to dissect a single image.
Outstanding explanation. I had to watch it again to refresh my memory. Well done!
I always assumed it was a counterweight to kip the nose down in big waves... the real reason is even cooler. Good video
I was brought here because of the 3 seals chillin on the bulbous bow.
I guess what it was for after watching the clip at the start, feeling very smart right now
SILJA LINE!!!!🇫🇮🇫🇮🇫🇮🇫🇮 Suomi
PERKELE TORILLE SAATANA SILJA GALAXY
SUOMI PERKELE
Silja line o paras👍👍
I navigated in one of those ❤️
Have you Finnished
Wanted to shout out the way you remind users to like videos without directly stating it, I and im sure many others appreciate your indirect approach
It also helps dampen pitching, albeit slightly. The sonar dome of T22 batch III frigates, which is a larger version of a bulbous bow, reduced slamming noticeably.
I almost bailed out at “...lets think back to mathematics...” but pleased I stuck it out! 😀 Excellent explanation and it seems you have attracted quite a number of intelligent and observant comments as well. 👍👍👍
You make it easy to understand..that is a very difficult thing to do...thanks
Thanks When I became the sun. Glad it was understandable.
I've Actually seen Tallink or Silja Galaxy in real life when I visited Latvia, Beautiful ship.
I've been on it many times.
Perfect video. Short, sweet, to the point with no waffle or bullshit. Thank you
Cool and to the point video! I knew the bulbous bow helped ships sail more smoothly but until now didn't know the principle behind it. 🚢
Just popped up in my suggestions thumbs up though!! You piqued my interest and now I know some thing I never knew that will probably serve me no purpose but I'll pull out one day like yah know what that thing does and explain
0:22 "looking at these different pictures, you can see the ships are all different sizes" he says while showing only the very tip of the ship with no reference point in the picture. It's not possible to judge the actual size of the ship solely from those pictures :)
🤣😂 I was thinking the same thing. Like: am I supposed to do the calculus and physics on the water amd guess the speed and extrapolate the size?... Uh... No... Just zoom out. 🤣😂 besides, i dont know how to do that crap anyways. Lmao
Of course it is. If you don't see it, you don't see it I guess ;)
Thanks!
I learn so much from your videos! Keep it up!
I really appreciate how you get right to the point from the start.
UA-cam recommending answers to a question I didn’t know I needed the answer to
Q: Is the bulb designed for a specific speed or does it cancel out the waves at any speed?
Great series of videos. I am learning so much!
Only for a specific speed its only good for ships that traval mostly at a constant speed
I learned something new today! The more you know 💫
Fun Fact: when its no longer needed they neuter the bow so that the ship can no longer mate with a partner
You've killed it with your verbosity just say, " ...no ship mates." That way, you nail a pun as well!
🤣
I always assumed it was to protect the ship from a front impact. But I never had a real answer and didn't even know what they where called. This makes alot more sence. Thank you!
I've lived this long not knowing what the bulbous bow was for, nor did I know why ships are painted red below the water line, and I've learned both in one night. Pure UA-cam genius! Outstanding video, and not even one comment mentioning Ron Jeremy from the Peanut Gallery.!
I ALSO HAVE A 'BULBOUS BOW.'
I'm trying to think, how can I use the information from this video to develop a pickup line at the club.
Did you found out yet ? I'm interested
My frontal Bulbous Bow serves a very specific purpose as well ;)
This is the first time i came across such an easy explanation. Thank you so much...
Coming from a family of sailors for over 5 generations, I’m no expert, but I do know this.., The configurations belong the water line are the most critical when dealing with speed, handling and fuel/wind economy. It’s all about the math, not looks.
Fabulous video.
Sometimes when a daddy ship loves a mommy ship...
or just two ships passing in the night.
Until they get married, then the bulbous bow becomes obsolete
So baby ships?
I thought it was just there to smash smaller boats out of the way
Herbie, Herbie, Herbie . . . naughty.
"We can model this wave mathematically.."
me: oh noooooo...oh this isnt so bad lol
You gotta learn mathematics, otherwise you'll get screwed in life by someone who understands it.
Even with the bulb though, the best battleship of the US navy, battleship Iowa, didn’t have a bulbous bow, but it had a tapered bow design instead, and hey, she reached 33 knots! For reference, a destroyer travels at a minimum 37 knots. That’s very fast
I can't imagine the US Navy is particularly worried about saving on fuel costs with their unlimited military budget lol.
I love your videos, finally something to learn on the internet
Me: *trying to sleep*
UA-cam's recommendations at 3 A.M.:
These always scared me cause they make it look like the ship is super buoyant on the bottom and it would flip
I was told, as a kid, that this was discovered by an engineer after he observed his son playing with toy boats in the bathtub. His son had fastened a pingpong ball to the front of one of the boats and it appeared to move more easily than the other boats.
Father, pass me the hot glue gun. I wish to fasten a pingpong ball to the front of my 3 foot long bath-boat and perform some tests. Yes I'll be careful not to drop it into the water.
Doesn't really pass the sniff test that one. Can't imagine the reduction in drag being in any way perceptible on that scale.
I've been wondering what the purpose of those things were and now I know.
So thank you for clearing up one of life's great mysteries for me.
I finally see a practical application of the sine and cosine waves taught in school years ago.
wow EXCELLENT video. I am now your newest subscriber.
I also saw ur "why is it called a "bridge" video. Great stuff. Now just gotta catch up with ur other work
I also saw ur "why is it called a "bridge" video. Great stuff. Now just gotta catch up with ur other work
On millitary warships, they modify the bulbous bow into a sonar dome to track submarimes 👍
Some may put it in the bulb. Others just have the sonar dome hanging below the bow. The bulb is a nice empty space to use if you can though.
The first ship is silja line from finland! Perkele
Estonian company Tallink owns that ship what's called MS Galaxy. Silja Line is just a brand name nowadays after Tallink took over that company in 2006.
Joo perkele
Am I the only one finding it enjoyable that in the beginning of the video there was a ship in the archipelago of Stockholm
Would have liked an explanation on how the bulbous bow helps generate those kind of waves. The physics of various designs etc.