We used to calculate ship's weight before but I'm more of assisting my superior.Anyway I used to calculate barges as they were simpler.On the big ship I mostly take record of tanks sounding.
ViniByte might come up in a conversation sometime, if your brain found it important and you remember the details, small or big. It’s amazing how many “useless facts” I’ve learned watching videos like these have come up as an additive to conversations about various things.
Well, the next time you see a ship, you can point this out, and say "Damn that ship's sitting pretty low in the water, carrying a lot of cargo..." and then go into how you weigh a ship....
I’m so glad the principles I’ve learned as an engineer can help me predict the answer to questions like this before watching the video. It’s so great to know that not only was I taught well, but there are genius creators like you on TH-cam here to make the “hard” stuff accessible for us all
@@bitpumpkinn2923 Pffft hahaha. Even many americans engineers think imperials are retarded compared to SI units. Meanwhile not a single SI user will say that imperial units are better. Your units are so superior that they are all literally DEFINED using the metric system and NASA already used metric units when going to the moon in 60s. Superior, right...
Never thougt of that and the first thing i thought by weighing a ship was 'Well, you put it in a dock and measure the displacement'. But when you said you measure it all the time, i was a little bit sceptical about my solution. The answer was so simple, thanks for the great video!
without watching the video, i'm guessing its something to do with the amount of water displaced, buoyancy, and Archimedes principle. edit: yay i was right! now if only i remembered that in high school...
Nobody: Will it fit in my Honda? Hold my beer Am I a joke to you? Asking for a friend Everybody gangsta End this man’s whole career He protecc, he attacc … Sexual/genitalia innuendo Scatological/potty joke Question of quantity answered yes Plot twist Left/entered the chat Gaming reference Dislikes are from I’m a simple man Not gonna lie Last time I was this early Legend has it That’ll buff right out Fun fact (X) be like (X) intensifies (X) wants to know your location Ha ha (X) go brrrrr POV: (X) YT algorithm counting down years Who’s watching in current year? You Tube recommendations So you've chosen death? Understandable, have a great day Punch line below read more
@@W0DAN88 sure it is. ! Do u feel better about yourself now? It was litterally a joke of a comment but hey.. if ya wanna chime in Please do so. I live in West palm. BEACH FL.. SURROUNDED BY WATER.. oWned 2 boats at one time or another.. But didnt feel like bragging. . I did however give the appropriate comment that flowed with the purpose of this video. But theres always sumone That thinks they know it all... But hey.. Have at it. I know.. 134 other people enjoyed my comment, while u.. , well.. Yeah.. just trolling middle of the night. Bravo.. Bravo. Go back to playing videos games kid.
I have watched ur videos before and I was like everyone in the comment section. But now I am actually studying maritime officer and I am actually learning all about this and ur videos really helpen me get a headstart. Ur videos also helped me see this is the job I wanna do, so thx for that.
I will absolutely never ever need this information ever, not at any single point in my life... But I still feel like this is crucial info I need to know
I'm driving all the way from Atlanta Georgia to Chattanooga Tennessee, and I must say I truly appreciate the time you've taken to make this video as well as your other videos.
Even when I know the answer to the question I still watch your videos. I find that even when I know how something is done (or why), I will still learn something loosely related to the topic that I didn’t know previously. In this case it was that larger vessels experience fluctuations in the alignment of their hull so frequently that there is terminology for it.
Came here from your most recent video but the comments are absolute cancer. Fantastic editing and information delivery! I look forward to seeing more of your stuff. Cheers, you earned another subscriber
i bought a small 20 footer from someone , been wondering how much it weighs for a while now . cool now all i gotta do i chuck the boat in my swimming pool and now know the weight now!
I spent over twenty years doing draught surveys as a cargo surveyor, the good old "mean of means of means" and the lifesaver "ship's constant". Nicely described
Thanks a lot for the content. As stated by other viewers, and as a landman with recurring questions on boats, these are the kind of videos that leave me wiser. And as is the case with similar channels on other topics, I am dumbfounded by the amount of red thumbs... if you are not interested, just go away.
Me:I like motovehicles videos,technology, animals, TH-cam:Ok then we will recommend you a ship video even you don't have a cargo to ship . Me :Ok let me see it TH-cam:Here it is. Me:It's very informative and in have enjoyed it . TH-cam:We will recommend another one . Me:😊😊🤗🤗
Excellent ! Since I'm from the aviation side, I knew about weight and balance, but was curious how it was done on ships. Really enjoyed and Thanks ....
@@jekiapp balance points taking the weights at known arms from the aircraft's datum point then calculating using sign convention (neg. & pos.). All aircraft will have a manual section giving the datum and known arms, enabling you to determine the aircraft's basic weight and c of g,
Pretty much. I've never done it yet in my pilot training (my instructor doesn't seem overly concerned with it - probably because he only cares if our combined weight is in spec), but if you look at the pilot operating manuals for most aircraft you see a reference point (ours is the front of the aircraft just behind the propeller, and the centre-points for where various things get loaded into the aircraft. For instance, a distance (Relative to the front of the aircraft) that shows where each row of seats is, where the cargo holds are, and where the fuel tanks are. You then calculate (using either actual weights, or estimates) how much weight is in each location, and then you use a bunch of tables to calculate your weight and balance. There are usually only figures for balancing the aircraft front to back, not side to side, since that's far more important. An aircraft that's too tail-heavy is unstable, and behaves chaotically. An aircraft that's too nose-heavy becomes stable to the point of being uncontrollable. The balance between the left and right doesn't matter anywhere near as much. Calculating the weight and balance for an aircraft is very important, because if it's out of designed ranges the aircraft can become dangerous to fly, if not entirely unflyable... I also hear some aircraft can automatically determine weight and balance by using force sensors on the landing gear and measuring how much pressure is on each point. Don't know how common it is, but I know it exists...
@@ruthedwards7775 thanks for your explanation, but I don't understand anything you just said :D maybe better if I jot down How to weigh aircraft in youtube or google.
@@jekiapp the easiest way is that every aircraft has it's dry operating weight, given by the manufacturer, then you start loading the aircraft, giving the zero fuel weight, and finally you add the fuel weight, which on small aircraft gives you the take off weight.
We do something similar with aircraft. Passengers are split into average men, women, children and babies (babies weighing nothing for our purposes). All the hold baggage is weighed as it is checked in, all the hand baggage is included in the average weights of the passengers, so we end up with pretty good idea of the weight we're going to take off with. Then there is a safety factor on everything from weight to headwind component to length of the runway. All that gives us figures for the speeds at which we take off and climb and the amount of power we need to set on the engines. That is great for getting us off the ground safely, and the gross weight is still needed by the flight management computers for calculating fuel use At the other end, the actual speeds we need to fly the aircraft are quite critical when you make an approach at your destination. The speeds we use here are not based on any figures we've entered before, but on all the probes on the outside of the aircraft. If you know the temperature, altitude, airspeed and angle of attack then you can work out the weight of the aircraft. That figure isn't particularly useful to us but what is good is knowing when you look at your instruments, the characteristic speeds are accurate based on the way the plane is flying.
love your explanations. I am marine eng. so its nice to show your videos when I want to explain GPS, Toilet on a ship.... 10 years old boys as a lot. ;-)
When I saw this video I thought, "I guess just displacement." I had no idea there were so many other factors that went into it. I didn't even consider how you would measure the height of water displaced.
You don't though. If you measured the height of water displaced you would be measuring the sea level. You are measuring how far into the water the ship is. Minor I know but im nit picky.
The video is quite helpful for those who are not familiar with the subject yet there are few minor setbacks to be remedied about the video as well. First, volume of the ship is not an accurate term where it should be "underwater volume of the ship". Second is about physics. As you may know volume×density results in mass not weight. To obtain weight you have to consider gravitational acceleration (g) therefore formulation would be D (Displacement of ship) v(underwater) × d(water) × g, or you just simply refer the result as displacement mass if you wish not to bother with g. Third is displacement of the ship is equal to overall weight of the ship therefore you should subtract lightweight of the ship (weight of hull, steel structural members, machinery, outfitting etc.) to yield deadweight capacity of the ship which is total cargo carrying capacity of ship including cargo, fuel oil, provisions, potable water etc. Finally you should have perhaps mentioned about block coefficient, freeboard calculations and allowable draught values of a ship.
Very good explanation. But miss to explain the symbol next to the draft marks. This symbol is call the “Freeboard” mark. Freeboard mark: Vertical distance from the main deck of a vessel to the cargo line indicating the maximum authorized draft by the shipbuilder.
1) step on scale & write down your own weight. 2) step off the scale & pick up the ship. 3) while holding the ship step back on the scale & note the weight. 4) subtract your weight from the total and there is your answer.
The BEST explanation of what those numbers on a ship are for. We probably ALL knew they measured how deep the ship Sat ibn the water but calculating the weight of the ship was a revelation. (OK, maybe it just rekindled a long forgotten math problem in school, which, BTW, was "a long time ago, in a galaxy...")
What's really fun is doing a deadweight survey. That's where we work out the weight of the ship itself, as opposed to all the stuff loaded on it. That means going thought and weighing up all the stuff (and I mean ALL) that is not a permanent part of the ship, doing the draft readings like the video shows, then deducting the non-ship weight from the total displacement. I once spent an afternoon weighing 3 tons worth of bolts is small bins on one of these jobs. oh what fun...
Interesting, because I studied this in mechanic of fluids in my past semester, but it didnt came to mind we couls use it to weigh a ship! Very interesting to know it! 😊
Easy !! Step 1: use GRU's shrink ray and point at ship: when 1/2000th the size, grab out of the water and place on gram scale. Be sure to grab entire ship with cupped hands and lift up Step 2: multiply mass by 2000 and place boat back in water. MAKE SURE TO STEP BACK at least 2000 the width of the hull Step 3: wait for naffario effect to make ship back to it's original size and you're done !! 👍🚢🚢
Well it can be explained even in simpler terms: Step1: Remeber Archemedies principle. That is the amount of water displaced by an object is equal to its weight. Step2: Using the same principle, Initial draught survey is conducted when the ship is built and its empty displacement (the amount of water it displaces when the ship is empty+its equipment on board+crew quarters+fuel on board). From here we get the empty weight of the ship. Step3: Here the cargo is loaded on the ship, and the amount of water displaced can be noted. Step4: DWT(Dead Weight Tonnage) or carrying capacity is. Loaded displacement- Actual displacement = Net carrying capacity of the ship.
I used to be a dock operator at a rock quarry on the Ohio river west of Louisville KY. My job was to operate a set of winches that moved a barge up and down river as large dump trucks dumped material into the barge. When finished I had to walk out on the barge and measure the freeboard at every corner. Hopper barges loaded down to 18" of freeboard had around 2200 tons onboard and flat deck barges were right around 1200. We only measured 4 points as barges are only about 200 feet long. Once measured those numbers were radioed up to the switchboat pilot and he wrote them down in a log.
As a Ungrad Marine Engineer, this video shows how to calculate more on the Deadweight of the ship. Meaning the weight which being use for commercial purposes. The beauty lies in lightweight too, the weight of an empty ship. The lightweight can be used to sell old ships before smelting it. FYI since the density of each cargo can be different, the engineer must design a strike balance between volume capacity and the tonnage. Note: If youre interested to sell your old ship and your ship is located near SEA, contact me and ill give you the best deal.
Seriously I laid in bed last night wondering how they weighed it. I came up with a couple crazy ideas in my head that practically dont make sense. Awesome video
I learned this method at school in the form of a funny story in which, the king of Syracuse orders Archimedes to find out if his new gold crown is of pure gold or not. When Archimedes finds the method, he shouts victoriously : "Eureka ! "
I was calculating this by hand in maritime school for bulk cargo (grain)...final exam done in 45 min. This is first mate's (primo) job by using software now days .
I do security at a shipyard. I work nights. Not many come in on my shift but this one did and soon as they docked a crew got off to inspect everything. Saw one guy go out and take pictures of the numbers. Now, I am sure that happens daily but they do all their work during the day when I am off. 10-22-20
Before watching the video, I knew this had something to do with Archimedes principle. And only 1:22 minutes in, and it's clear to me like the sun 🌞 Alhamdulillah! Thank you for creating such an interesting video.
Thats what I was thinking. Looking at waves lapping at 10cm high numbers and trying to decide what the level was sounds like it would give you an accurate number plus/minus 10,000 tonnes.
@Bogdan Belcea I would be very surprised if that was NOT the case; I think it would be quite trivial to write a computer program to do all the calculations, i.e. where you just have to enter the data from that spec sheet that was illustrated in the video. Of course, each type of ship would have its own spec sheet. Come to think of it, i would even think that the most common types have already been entered into such a program, so that the operator - which would most likely be the First Mate (second in command) - can just call up that set of data, and hey presto, you get your weight with a minimum of fuss.
I would imagine in theory it's possible to fully automate this using liquid sensors. Probably some issues around waves and the like... But still. - liquid level sensors are pretty common nowadays on the inside of water tanks, I assume they could be adapted to be mounted on the outer hull of a ship (though that might require more durable construction) With sensors around the hull automatically measuring the water level, feeding it to a computer and comparing it to the specs for the ship, you'd have a near instant and consistent weight readout. You'd probably also get some bonus realtime measurements out of it, like the angle the ship is at relative to the water's surface, and how much it's flexing. (especially if there's larger numbers of these sensors, not just 6 to match the visual markers.) Still, no idea if anyone's bothered with that level of automation of a process like this just yet...
I’ve literally just gone down the rabbit hole watching all these videos... I have no practical purpose for this knowledge or anything but god damn is it interesting
UK Canal boats, in the days of commercial usage used to pay a toll on the amount of cargo. This was judged by the lock keeper at toll stations using a gauging stick. Basically a stick with marks on it to estimate the draft of the boat and hence its load. Instead of measuring the draft from the bank the keeper would measure it by getting on board so that his weight, off to one side would increase the apparent draft. The boat man in an attempt to equalise this would hang off the other side of the boat.
This is a routine calculation for the mates on most cargo vessels, it is a bit more complicated than your very good simple explanation. On most bulk carriers the mate and a cargo surveyor (employed by customer) take the draughts together and work out and agree how much has been loaded. This is quite a complex calculation, but gives a very accurate figure provided the draughts are read correctly, this is an art in itself on exposed berths.
This is a fantastic video, thank you for sharing!! I suspect that the viewers complaining had trouble at the first sign of math that required more fingers than they had.
I always thought it had something to do with those numbers on a ships hull...I use to work in Toronto, Canada in heavy equipment. and when I was helping unload the huge ships that transport raw sugar to the dock, every hour or two a person would come around with a clipboard and look at each number on the side of the ship where the water level was, and then go back on the ship..after he went back they sometimes would start taking sugar out of a different hopper on the ship. So I always wondered why he kept coming out to look at the numbers on the hull..lol kinda had a idea tho..
What is more critical is that you wont be allowed to cast off. The Plimsol mark (the O with a dash through it and letters) shows the maximum weight the ship may be at. This came from back in the time where ship owners, once the ship is at the end of its life, would overload the ship extremely to the point where it would surely sink. Sweet sweet insurance money you see. "Nothing says we cant load that ship that much, we didnt know it would sink from this". Thus the plimsol mark was invented for the safety of the crew and to prevent insurance fraud.
Ben Conway Depends. Many questionable things shipping companies do is simply because they have to to keep up with the competition. If noone else can benefit from it either, im pretty sure they were in favour for it since it meant lower insurance rates and safety of crew. This way they didnt risk losing good men in the process. At that time you didnt need a "good riddance", sailors did it themselves either by firing the bad sailor at the next port (nothing that i know of could stop them from simply abandoning a sailor they didnt like at the next port) or there would be what we call in the shipping industry as "slippery decks", where someone mysteriously would fall overboard, have a serious accident or simply show up with lots of bruises, that the other crew members definitely didint have anything to do with.
i like how the tittle is in all caps, you expect some intense Kyle to come in screaming telling u 2 like and subscribe and so on, the u get this calm chad with actual cool information
Great job & thanks. I know that highly accurate tables are used but perhaps you could have gone just one teensy step further, by explaining where they fit within the vessel's "block coefficient". Well done though.
Great video and great channel! Deserves far more subs. But I have a feeling that it will happen! The YT Algorithm finally worked and give a good recommendation. Probably this will happen to others as well.
Just a note from a physicist: the product of volume and density does not give weight, it gives mass. Mass is the amount of matter in an object, while weight is the force on the object due to gravity
![Search & Rescue Transponders [SARTs] | Operation and Use of SARTs in emergency situations](http://i.ytimg.com/vi/Aq_DEuFf58k/mqdefault.jpg)
![Search & Rescue Transponders [SARTs] | Operation and Use of SARTs in emergency situations](/img/tr.png)
I literally will never use this information in my entire lifetime but man did i spent my 5 minutes well.
maybe u do if u work on a shipyard
@@ssi3262 😂
We used to calculate ship's weight before but I'm more of assisting my superior.Anyway I used to calculate barges as they were simpler.On the big ship I mostly take record of tanks sounding.
ViniByte might come up in a conversation sometime, if your brain found it important and you remember the details, small or big. It’s amazing how many “useless facts” I’ve learned watching videos like these have come up as an additive to conversations about various things.
Lmao no cap doe
I have no practical purpose for knowing this information... not one... but damn that was interesting.
Quiz shows?
Become a marine engineer or deck officer, you’ll get sick of this pretty quickly 🤣
I just add it to all the other useless information that I will never use that floats around in my brain.
Well, the next time you see a ship, you can point this out, and say "Damn that ship's sitting pretty low in the water, carrying a lot of cargo..." and then go into how you weigh a ship....
QuantumRift people don’t realise it, but as much engineering goes into making a large ship float as does Making a large plane fly
this channel will have a lot more subs in the future, thanks for the high quality explanation
ooh neat, episodes on subs will be cool
will they form wolfpacks? I might need some more escorts for my convoys
I can see this guy having a few hundred thousands or a few million.
I really prefer the videos on surface ships.
I’m so glad the principles I’ve learned as an engineer can help me predict the answer to questions like this before watching the video. It’s so great to know that not only was I taught well, but there are genius creators like you on TH-cam here to make the “hard” stuff accessible for us all
I figured it would have to do with water displacement, but exactly how that was done was a lot simpler than what I had in mind.
I'm not an engineer, still called it.
Fascinating. Genius to paint the numbers on the ship to see how much lower the ship is telling you the weight. It's such a simple brilliant solution.
And then there are Americans with their units
@@clansman89 Uhh, you forgot to put 'superior' right before 'units'...
@@bitpumpkinn2923 lol
@@bitpumpkinn2923
Pffft hahaha.
Even many americans engineers think imperials are retarded compared to SI units. Meanwhile not a single SI user will say that imperial units are better.
Your units are so superior that they are all literally DEFINED using the metric system and NASA already used metric units when going to the moon in 60s.
Superior, right...
@@ahriman935 nasa used both imperial and metric on the moon landings
I'm adding plimsoll marks to the mother-in-laws pool: finally gonna figure something out
😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂
Ha ha ha!!! Very clever indeed...
Good one
🤣🤣🤣🤣
And if she floats, she's a witch!
I am a custom broker from Greece, and your videos make me learn so much that I didn't concern when I do my job. Thanks subscribe
Absolutely wonderful, I had never given a thought as to how the weight of the cargo is measured. Now, I got a clear idea.
Never thougt of that and the first thing i thought by weighing a ship was 'Well, you put it in a dock and measure the displacement'. But when you said you measure it all the time, i was a little bit sceptical about my solution. The answer was so simple, thanks for the great video!
Yeah, I was thinking the same thing.
Nobody:
TH-cam:
Hey, wanna know how to weigh a ship?
I'm not complaining tho.
For some reason many people don't seem to be interested in the details that keep the world running :I
@@FreakSX93 agree
@@FreakSX93 same
without watching the video, i'm guessing its something to do with the amount of water displaced, buoyancy, and Archimedes principle.
edit: yay i was right!
now if only i remembered that in high school...
Nobody:
Will it fit in my Honda?
Hold my beer
Am I a joke to you?
Asking for a friend
Everybody gangsta
End this man’s whole career
He protecc, he attacc …
Sexual/genitalia innuendo
Scatological/potty joke
Question of quantity answered yes
Plot twist
Left/entered the chat
Gaming reference
Dislikes are from
I’m a simple man
Not gonna lie
Last time I was this early
Legend has it
That’ll buff right out
Fun fact
(X) be like
(X) intensifies
(X) wants to know your location
Ha ha (X) go brrrrr
POV: (X)
YT algorithm counting down years
Who’s watching in current year?
You Tube recommendations
So you've chosen death?
Understandable, have a great day
Punch line below read more
You definitely deserve a lot more subs and views, great video!
Thanks Apfelmann. Glad you enjoyed it.
Maths and physics are beautiful sciences,s .Without them we would in fact be lost at sea ( terrible pun!) Cheers and good content. Len.
Not sure why this was in my recomendations.. But, i feel ALOT smarter than the average person now that i have a fact.. That most people dont know
Well, it's an observable common-sense thing: If you see a ship sitting low in the water, you know its carrying a lot of cargo...
@@QuantumRift you are absolutely Correct .. For those that have SHIPS AROUND THEM OR ARE CLOSE TO AN OCEAN..
@@MrFinesse316 I've been living near an ocean my entire live
But isn't that totally obvious even for someone who never was near a boar/ocean?
@@W0DAN88 sure it is. ! Do u feel better about yourself now?
It was litterally a joke of a comment but hey.. if ya wanna chime in Please do so.
I live in West palm. BEACH FL..
SURROUNDED BY WATER.. oWned 2 boats at one time or another..
But didnt feel like bragging. .
I did however give the appropriate comment that flowed with the purpose of this video.
But theres always sumone That thinks they know it all...
But hey.. Have at it.
I know.. 134 other people enjoyed my comment, while u.. , well.. Yeah.. just trolling middle of the night.
Bravo..
Bravo.
Go back to playing videos games kid.
I'm a marine mechanical engineering student and I've honestly learned more from you than I have for the past 3 years in college lol, terrible innit
I assume you graduated and are now working. How are things? From a 4th year civil engineering student
@@pokeman316 quite alright, landed a port state control job somehow now i've moved on to marine search and rescue.
I'm a navigation Student from Jamaica. I'm gonna let my schoolmates know of this channel. Keep up the good work
as someone who wishes to be a naval engineer, I'm sad I didn't find this channel earlier.
I've worked on ships for over 10 years and I still learn something new every time I watch one of your videos! Keep up the good work and good content!
I have watched ur videos before and I was like everyone in the comment section. But now I am actually studying maritime officer and I am actually learning all about this and ur videos really helpen me get a headstart. Ur videos also helped me see this is the job I wanna do, so thx for that.
I will absolutely never ever need this information ever, not at any single point in my life... But I still feel like this is crucial info I need to know
You can always use this knowledge to wow your friends at parties ;)
I'm driving all the way from Atlanta Georgia to Chattanooga Tennessee, and I must say I truly appreciate the time you've taken to make this video as well as your other videos.
Even when I know the answer to the question I still watch your videos. I find that even when I know how something is done (or why), I will still learn something loosely related to the topic that I didn’t know previously. In this case it was that larger vessels experience fluctuations in the alignment of their hull so frequently that there is terminology for it.
Came here from your most recent video but the comments are absolute cancer. Fantastic editing and information delivery! I look forward to seeing more of your stuff. Cheers, you earned another subscriber
Oh great.. another high quality informative niche TH-cam channel... Exactly what I need at 3 am 🙄
Sarcasm detected by the sounds of it?
i bought a small 20 footer from someone , been wondering how much it weighs for a while now . cool now all i gotta do i chuck the boat in my swimming pool and now know the weight now!
That would be one way of finding out!
Silly billy....take it to the weigh station. Then ask them if they know where the nearest lake is.
I always wondered what those number were for. Now I have the formula for them. Thanks and well done.
This channel represents one of the best educational videos for shipping knowledge. I shall watch them carefully one by one subsequently.
I spent over twenty years doing draught surveys as a cargo surveyor, the good old "mean of means of means" and the lifesaver "ship's constant". Nicely described
Thanks a lot for the content. As stated by other viewers, and as a landman with recurring questions on boats, these are the kind of videos that leave me wiser.
And as is the case with similar channels on other topics, I am dumbfounded by the amount of red thumbs... if you are not interested, just go away.
Me:I like motovehicles videos,technology, animals,
TH-cam:Ok then we will recommend you a ship video even you don't have a cargo to ship .
Me :Ok let me see it
TH-cam:Here it is.
Me:It's very informative and in have enjoyed it .
TH-cam:We will recommend another one .
Me:😊😊🤗🤗
Soon you will likely also have train videos recommended. ;-)
@@Foersom_ Hahahaa absolutely yes that's TH-cam Algorithm..
I admire the simplicity of the explanation. Understood the formula perfectly
I'll keep this in mind for the next time I weigh a ship
Excellent ! Since I'm from the aviation side, I knew about weight and balance, but was curious how it was done on ships. Really enjoyed and Thanks ....
so how do they weigh an airplane?
@@jekiapp balance points taking the weights at known arms from the aircraft's datum point then calculating using sign convention (neg. & pos.). All aircraft will have a manual section giving the datum and known arms, enabling you to determine the aircraft's basic weight and c of g,
Pretty much. I've never done it yet in my pilot training (my instructor doesn't seem overly concerned with it - probably because he only cares if our combined weight is in spec), but if you look at the pilot operating manuals for most aircraft you see a reference point (ours is the front of the aircraft just behind the propeller, and the centre-points for where various things get loaded into the aircraft.
For instance, a distance (Relative to the front of the aircraft) that shows where each row of seats is, where the cargo holds are, and where the fuel tanks are.
You then calculate (using either actual weights, or estimates) how much weight is in each location, and then you use a bunch of tables to calculate your weight and balance.
There are usually only figures for balancing the aircraft front to back, not side to side, since that's far more important.
An aircraft that's too tail-heavy is unstable, and behaves chaotically.
An aircraft that's too nose-heavy becomes stable to the point of being uncontrollable.
The balance between the left and right doesn't matter anywhere near as much.
Calculating the weight and balance for an aircraft is very important, because if it's out of designed ranges the aircraft can become dangerous to fly, if not entirely unflyable...
I also hear some aircraft can automatically determine weight and balance by using force sensors on the landing gear and measuring how much pressure is on each point.
Don't know how common it is, but I know it exists...
@@ruthedwards7775 thanks for your explanation, but I don't understand anything you just said :D maybe better if I jot down How to weigh aircraft in youtube or google.
@@jekiapp the easiest way is that every aircraft has it's dry operating weight, given by the manufacturer, then you start loading the aircraft, giving the zero fuel weight, and finally you add the fuel weight, which on small aircraft gives you the take off weight.
Fabulous. It all boils down to how well the naval architect did his job and how well the yard followed the plans. Good enough.
I always love these simple elegant solutions people come up with to solve a very difficult sounding problem.
I have no idea why at 2am I watched this video. I guess curiosity. Very well explained. Thank you
TH-cam : C'mere boi let's learn to weigh ship
Me : cool let's go
We do something similar with aircraft. Passengers are split into average men, women, children and babies (babies weighing nothing for our purposes). All the hold baggage is weighed as it is checked in, all the hand baggage is included in the average weights of the passengers, so we end up with pretty good idea of the weight we're going to take off with. Then there is a safety factor on everything from weight to headwind component to length of the runway. All that gives us figures for the speeds at which we take off and climb and the amount of power we need to set on the engines. That is great for getting us off the ground safely, and the gross weight is still needed by the flight management computers for calculating fuel use At the other end, the actual speeds we need to fly the aircraft are quite critical when you make an approach at your destination. The speeds we use here are not based on any figures we've entered before, but on all the probes on the outside of the aircraft. If you know the temperature, altitude, airspeed and angle of attack then you can work out the weight of the aircraft. That figure isn't particularly useful to us but what is good is knowing when you look at your instruments, the characteristic speeds are accurate based on the way the plane is flying.
love your explanations. I am marine eng. so its nice to show your videos when I want to explain GPS, Toilet on a ship.... 10 years old boys as a lot. ;-)
When I saw this video I thought, "I guess just displacement." I had no idea there were so many other factors that went into it. I didn't even consider how you would measure the height of water displaced.
You don't though. If you measured the height of water displaced you would be measuring the sea level. You are measuring how far into the water the ship is. Minor I know but im nit picky.
Damm the internet is such a great place. Well explained sir
Now, If someone ever asks me to weigh their ship.
Go on.
@@concept5631 Are you asking? Bring it on over.
Great content! Thank you for the effort. Very enjoyable
Thanks Guillaume
The video is quite helpful for those who are not familiar with the subject yet there are few minor setbacks to be remedied about the video as well. First, volume of the ship is not an accurate term where it should be "underwater volume of the ship". Second is about physics. As you may know volume×density results in mass not weight. To obtain weight you have to consider gravitational acceleration (g) therefore formulation would be D (Displacement of ship) v(underwater) × d(water) × g, or you just simply refer the result as displacement mass if you wish not to bother with g. Third is displacement of the ship is equal to overall weight of the ship therefore you should subtract lightweight of the ship (weight of hull, steel structural members, machinery, outfitting etc.) to yield deadweight capacity of the ship which is total cargo carrying capacity of ship including cargo, fuel oil, provisions, potable water etc. Finally you should have perhaps mentioned about block coefficient, freeboard calculations and allowable draught values of a ship.
The way you explain things is just so perfect for me. Great graphics too
Please never ever ever add background music or anything to your videos, your voice is the most relaxing thing on the planet
Very good explanation.
But miss to explain the symbol next to the draft marks.
This symbol is call the “Freeboard” mark.
Freeboard mark: Vertical distance from the main deck of a vessel to the cargo line indicating the maximum authorized draft by the shipbuilder.
1) step on scale & write down your own weight.
2) step off the scale & pick up the ship.
3) while holding the ship step back on the scale & note the weight.
4) subtract your weight from the total and there is your answer.
Someday Im gonna impress someone with this knowledge. Thank you very much. hehehehe
The BEST explanation of what those numbers on a ship are for. We probably ALL knew they measured how deep the ship Sat ibn the water but calculating the weight of the ship was a revelation. (OK, maybe it just rekindled a long forgotten math problem in school, which, BTW, was "a long time ago, in a galaxy...")
The volume of the ship below the sea level times the density of the water.
I love you all.
I have seen the numbers on the bow, stern and mid ship but I never knew how they were used until now. Thanks for sharing this interesting information.
I never thought I had an interest in ships, but this channel is fascinating.
You have a great channel sir. You answer questions I never knew I had.
What's really fun is doing a deadweight survey. That's where we work out the weight of the ship itself, as opposed to all the stuff loaded on it. That means going thought and weighing up all the stuff (and I mean ALL) that is not a permanent part of the ship, doing the draft readings like the video shows, then deducting the non-ship weight from the total displacement. I once spent an afternoon weighing 3 tons worth of bolts is small bins on one of these jobs. oh what fun...
I always wondered what those numbers were for I learned something this morning thank you
Interesting, because I studied this in mechanic of fluids in my past semester, but it didnt came to mind we couls use it to weigh a ship! Very interesting to know it! 😊
Here before your channel blows up
Easy !!
Step 1: use GRU's shrink ray and point at ship: when 1/2000th the size, grab out of the water and place on gram scale. Be sure to grab entire ship with cupped hands and lift up
Step 2: multiply mass by 2000 and place boat back in water. MAKE SURE TO STEP BACK at least 2000 the width of the hull
Step 3: wait for naffario effect to make ship back to it's original size and you're done !! 👍🚢🚢
Well it can be explained even in simpler terms:
Step1: Remeber Archemedies principle. That is the amount of water displaced by an object is equal to its weight.
Step2: Using the same principle, Initial draught survey is conducted when the ship is built and its empty displacement (the amount of water it displaces when the ship is empty+its equipment on board+crew quarters+fuel on board). From here we get the empty weight of the ship.
Step3: Here the cargo is loaded on the ship, and the amount of water displaced can be noted.
Step4: DWT(Dead Weight Tonnage) or carrying capacity is. Loaded displacement- Actual displacement = Net carrying capacity of the ship.
Indian brain....
this channel is a treasure
I used to be a dock operator at a rock quarry on the Ohio river west of Louisville KY. My job was to operate a set of winches that moved a barge up and down river as large dump trucks dumped material into the barge. When finished I had to walk out on the barge and measure the freeboard at every corner. Hopper barges loaded down to 18" of freeboard had around 2200 tons onboard and flat deck barges were right around 1200. We only measured 4 points as barges are only about 200 feet long. Once measured those numbers were radioed up to the switchboat pilot and he wrote them down in a log.
As soon as you said "a ship will displace its own weight in water" I immediately went "wait... those numbers?!?" And it was true! Very interesting
I figured it would have to do with water displacement, but man is just drawing markers on the ship a lot simpler than what I was imagining.
As a Ungrad Marine Engineer, this video shows how to calculate more on the Deadweight of the ship. Meaning the weight which being use for commercial purposes. The beauty lies in lightweight too, the weight of an empty ship. The lightweight can be used to sell old ships before smelting it.
FYI since the density of each cargo can be different, the engineer must design a strike balance between volume capacity and the tonnage.
Note: If youre interested to sell your old ship and your ship is located near SEA, contact me and ill give you the best deal.
Seriously I laid in bed last night wondering how they weighed it. I came up with a couple crazy ideas in my head that practically dont make sense. Awesome video
Loading master: we've reached maximum displacement
Ship: I'm...I'm not fat!
I learned this method at school in the form of a funny story in which, the king of Syracuse orders Archimedes to find out if his new gold crown is of pure gold or not. When Archimedes finds the method, he shouts victoriously : "Eureka ! "
I was calculating this by hand in maritime school for bulk cargo (grain)...final exam done in 45 min. This is first mate's (primo) job by using software now days .
As a Draught Surveyor this is a nice short video with the simple principles.
I do security at a shipyard. I work nights. Not many come in on my shift but this one did and soon as they docked a crew got off to inspect everything. Saw one guy go out and take pictures of the numbers. Now, I am sure that happens daily but they do all their work during the day when I am off.
10-22-20
Before watching the video, I knew this had something to do with Archimedes principle. And only 1:22 minutes in, and it's clear to me like the sun 🌞 Alhamdulillah!
Thank you for creating such an interesting video.
Very interesting and informative, and very clearly explained. Thanks for sharing!
Now, I've done my time as a longshoreman, we used draft as a reference only.
Measurement for the sale was done by other means.
Thats what I was thinking. Looking at waves lapping at 10cm high numbers and trying to decide what the level was sounds like it would give you an accurate number plus/minus 10,000 tonnes.
It depends on the sice of the vessel and I would put it at a multiple of 10th of tons but you are absolutely right!
Always wondered. Thanks for the education and satisfying my curiosity.
As a naval architect, good job!
You lecture is fantastic and absolutely correct. Thank you for your painstaking work more grease to your elbow.
and or radar . your teaching way is so cool very easy to understand
Really interesting!!
Thank you so much for this knowledge. My mind and brain is happy now,.
How accurate is this ship weighing method?
Are digital versions now being used?
@Bogdan Belcea I would be very surprised if that was NOT the case; I think it would be quite trivial to write a computer program to do all the calculations, i.e. where you just have to enter the data from that spec sheet that was illustrated in the video. Of course, each type of ship would have its own spec sheet. Come to think of it, i would even think that the most common types have already been entered into such a program, so that the operator - which would most likely be the First Mate (second in command) - can just call up that set of data, and hey presto, you get your weight with a minimum of fuss.
I would imagine in theory it's possible to fully automate this using liquid sensors.
Probably some issues around waves and the like...
But still. - liquid level sensors are pretty common nowadays on the inside of water tanks, I assume they could be adapted to be mounted on the outer hull of a ship (though that might require more durable construction)
With sensors around the hull automatically measuring the water level, feeding it to a computer and comparing it to the specs for the ship, you'd have a near instant and consistent weight readout.
You'd probably also get some bonus realtime measurements out of it, like the angle the ship is at relative to the water's surface, and how much it's flexing. (especially if there's larger numbers of these sensors, not just 6 to match the visual markers.)
Still, no idea if anyone's bothered with that level of automation of a process like this just yet...
I’ve literally just gone down the rabbit hole watching all these videos... I have no practical purpose for this knowledge or anything but god damn is it interesting
Wow! One of the best channels!
I'm going to hold onto this knowledge I just learned and use it to impress someone someday.
UK Canal boats, in the days of commercial usage used to pay a toll on the amount of cargo. This was judged by the lock keeper at toll stations using a gauging stick. Basically a stick with marks on it to estimate the draft of the boat and hence its load. Instead of measuring the draft from the bank the keeper would measure it by getting on board so that his weight, off to one side would increase the apparent draft. The boat man in an attempt to equalise this would hang off the other side of the boat.
This is a routine calculation for the mates on most cargo vessels, it is a bit more complicated than your very good simple explanation. On most bulk carriers the mate and a cargo surveyor (employed by customer) take the draughts together and work out and agree how much has been loaded. This is quite a complex calculation, but gives a very accurate figure provided the draughts are read correctly, this is an art in itself on exposed berths.
Before watching: I'm sure it will be about Archimedes, Eureka and how deep the ship sinks in water
After: Yep, easy to guess. Still very nice video
Always wondered how that was done.
learned something new today!
Love ur channel,i subbed!!
This is a fantastic video, thank you for sharing!! I suspect that the viewers complaining had trouble at the first sign of math that required more fingers than they had.
very high quality video
I saw the title, said out loud to the empty room, "via displacement. Duh." Then opened the video to make sure I was right. Thank god.
I always thought it had something to do with those numbers on a ships hull...I use to work in Toronto, Canada in heavy equipment. and when I was helping unload the huge ships that transport raw sugar to the dock, every hour or two a person would come around with a clipboard and look at each number on the side of the ship where the water level was, and then go back on the ship..after he went back they sometimes would start taking sugar out of a different hopper on the ship. So I always wondered why he kept coming out to look at the numbers on the hull..lol kinda had a idea tho..
I LOVE THIS CHANNEL!!!
You also need to know the weight because if too heavy the ship can leave ruts on the surface, especially on a hot day.
What is more critical is that you wont be allowed to cast off.
The Plimsol mark (the O with a dash through it and letters) shows the maximum weight the ship may be at.
This came from back in the time where ship owners, once the ship is at the end of its life, would overload the ship extremely to the point where it would surely sink. Sweet sweet insurance money you see. "Nothing says we cant load that ship that much, we didnt know it would sink from this". Thus the plimsol mark was invented for the safety of the crew and to prevent insurance fraud.
@@SportSoulLife yep but the shipping companies didn't like it one bit
Ben Conway Depends. Many questionable things shipping companies do is simply because they have to to keep up with the competition.
If noone else can benefit from it either, im pretty sure they were in favour for it since it meant lower insurance rates and safety of crew. This way they didnt risk losing good men in the process. At that time you didnt need a "good riddance", sailors did it themselves either by firing the bad sailor at the next port (nothing that i know of could stop them from simply abandoning a sailor they didnt like at the next port) or there would be what we call in the shipping industry as "slippery decks", where someone mysteriously would fall overboard, have a serious accident or simply show up with lots of bruises, that the other crew members definitely didint have anything to do with.
i like how the tittle is in all caps, you expect some intense Kyle to come in screaming telling u 2 like and subscribe and so on, the u get this calm chad with actual cool information
Great job & thanks. I know that highly accurate tables are used but perhaps you could have gone just one teensy step further, by explaining where they fit within the vessel's "block coefficient". Well done though.
Great video and great channel! Deserves far more subs. But I have a feeling that it will happen! The YT Algorithm finally worked and give a good recommendation. Probably this will happen to others as well.
Thanks Daxelinho9
I love your videos, thank you for making them!!
Just a note from a physicist: the product of volume and density does not give weight, it gives mass. Mass is the amount of matter in an object, while weight is the force on the object due to gravity
And since shipping is still exclusive to earth we don't trip on the carpet design over such issue.
An excellent series , fascination stuff !