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rtaylor
If it was really important and the potentate wanted to know how much the Royal Barge weighed, he would have had it loaded onto a larger barge, marked the new new waterline and proceed as before!!! Paul s/v The Lord Nelson
If it was really important and the potentate wanted to know how much the Royal Barge weighed, he would have had it loaded onto a larger barge, marked the new new waterline and proceed as before!!! Paul s/v The Lord Nelson
Weighty questions
I'm not an engineer but I get to run the train at Christmas time! If you kept loading stones on the Royal Barge, wouldn't it displace as much as it weighs when the water pours over the gunnels and it goes to the bottom?
I'm not an engineer but I get to run the train at Christmas time! If you kept loading stones on the Royal Barge, wouldn't it displace as much as it weighs when the water pours over the gunnels and it goes to the bottom?
OK, PICTURE THIS!
You have two perfectly equally sized baseballs, one made of lead, the other of concrete: 1. You put each sphere in water and each sinks, displacing amounts of water equal in volume to the spheres. The weight of the water displaced is NOT equal to either sphere. 2. Now, you find a Styrofoam cooler large enough to float the lead sphere. The water displaced will equal the combined weight of the lead sphere and the cooler. 3. Finally, take the lead sphere out of the cooler and replace it with the concrete one. The water displaced will be equal to the combined weight of the cooler and the concrete sphere. The amount of water displaced by the cooler in #2 and #3 will not be equal, in weight nor in volume! Paul s/v The Lord Nelson PS to Fred: Being an engineer was my first choice also, but my grades got in the way!!!
You have two perfectly equally sized baseballs, one made of lead, the other of concrete: 1. You put each sphere in water and each sinks, displacing amounts of water equal in volume to the spheres. The weight of the water displaced is NOT equal to either sphere. 2. Now, you find a Styrofoam cooler large enough to float the lead sphere. The water displaced will equal the combined weight of the lead sphere and the cooler. 3. Finally, take the lead sphere out of the cooler and replace it with the concrete one. The water displaced will be equal to the combined weight of the cooler and the concrete sphere. The amount of water displaced by the cooler in #2 and #3 will not be equal, in weight nor in volume! Paul s/v The Lord Nelson PS to Fred: Being an engineer was my first choice also, but my grades got in the way!!!
Heavy Catalina
Read the Catalina website carefully - the 'displacement' given is actually base boat weight & not a true displacement. Optional equipment, fluids in the tanks, & your gear (anchors, rode, extra sails and rigging, pfd, kitchen stuff, bbq, etc) add to the weight. So possibly as well: water absorbed by the fiberglass while it was in the water. I don't know if the crane's slings and rigging add as well to the way the crane operator figures it. Thus the boat is heavier than the 11,700 lbs quoted by Catalina.
Read the Catalina website carefully - the 'displacement' given is actually base boat weight & not a true displacement. Optional equipment, fluids in the tanks, & your gear (anchors, rode, extra sails and rigging, pfd, kitchen stuff, bbq, etc) add to the weight. So possibly as well: water absorbed by the fiberglass while it was in the water. I don't know if the crane's slings and rigging add as well to the way the crane operator figures it. Thus the boat is heavier than the 11,700 lbs quoted by Catalina.
Opinions vs Research
This one's been too good, too. Try some Google research, lots on tap under "boat weight water displacement." There's this little thing called buoyancy involved. Read on the link, and try the Google for more info. Not worth copying it all here, since its' all there. Think submarines: try this: http://www.fleetsubmarine.com/diving.html Stu
This one's been too good, too. Try some Google research, lots on tap under "boat weight water displacement." There's this little thing called buoyancy involved. Read on the link, and try the Google for more info. Not worth copying it all here, since its' all there. Think submarines: try this: http://www.fleetsubmarine.com/diving.html Stu
Dan, you can run your train at Christmas
At first I thought you were wrong and I was going to tell you that you should forfeit your train, but I got to thinking and realized you made a correct point. When loading stones on the barge, the weight of displacement will equal the weight of the barge and contents all the way up to the point where the water reaches the gunnels. Then, when a small wave washes water over the gunnel, water will displace the atmospheric pressure INSIDE the volume of the space that is floating. That will upset the balance because now, the barge will sink ever so much lower and more water will come over the gunnel. The barge is now doomed because water rapidly displaces the air and eventually the barge sinks like a stone. Paul, you are royally right about calculating the royal weight of the royal pachyderm, except that Cluade probably works for the barge operator
, who gets paid by the pound (stone). If they paid the Royal Official of Weights and Measures a kick-back, and he kept his royal thumb on the scale when weighing the stones, the royal pachyderm would end up weighing greater than the weight of displacement and nobody would know the difference!
At first I thought you were wrong and I was going to tell you that you should forfeit your train, but I got to thinking and realized you made a correct point. When loading stones on the barge, the weight of displacement will equal the weight of the barge and contents all the way up to the point where the water reaches the gunnels. Then, when a small wave washes water over the gunnel, water will displace the atmospheric pressure INSIDE the volume of the space that is floating. That will upset the balance because now, the barge will sink ever so much lower and more water will come over the gunnel. The barge is now doomed because water rapidly displaces the air and eventually the barge sinks like a stone. Paul, you are royally right about calculating the royal weight of the royal pachyderm, except that Cluade probably works for the barge operator
, who gets paid by the pound (stone). If they paid the Royal Official of Weights and Measures a kick-back, and he kept his royal thumb on the scale when weighing the stones, the royal pachyderm would end up weighing greater than the weight of displacement and nobody would know the difference!Now, to the real challenge.
OK, now that we have this whole "how much the boat actually weighs and displaces" thing worked out, let's tackle the issue of how much the fish that the fishermen among us caught actually weighs! Does a fish displace his weight? If you put a mark on a tub, and then put the fish in the tub and you calculated how much water the fish displaced, would that be his weight, or is he neutrally, negatively, or positively buoyant, and if someone hung you down from a rope, would you able to pick him up? After that, if you put him in a styrofoam chest, would he still float? If he had swallowed a lead sinker, what effect would that have on his buoyancy? If you hooked an elephant, how could you get him in the boat? Ughhhh! This never ends! LOL!!!
OK, now that we have this whole "how much the boat actually weighs and displaces" thing worked out, let's tackle the issue of how much the fish that the fishermen among us caught actually weighs! Does a fish displace his weight? If you put a mark on a tub, and then put the fish in the tub and you calculated how much water the fish displaced, would that be his weight, or is he neutrally, negatively, or positively buoyant, and if someone hung you down from a rope, would you able to pick him up? After that, if you put him in a styrofoam chest, would he still float? If he had swallowed a lead sinker, what effect would that have on his buoyancy? If you hooked an elephant, how could you get him in the boat? Ughhhh! This never ends! LOL!!!
Ron here again
To clarify what I meant by an empty boat; three batteries, 20 gal of diesel, 6 gal of antifreeze in the hot water tank. That roughy totals 400 lb of non-factory stuff on board. Everything, including the cushions are removed. Unless the Perkins 30 diesel weighs a ton, there is still about 2000 pounds hiding somewhere. The boat weighed 14,000 from birth. The mast is not part of the equation (153 lb stripped) , as it is stored separately from the boat. Food for thought...........Since draft measurements for keels are done in salt water, my boat draws more in the fresh water she sails in. If displacement is calculated in salt water, would it then follow that displacement readings would be significantly different for fresh water ?
To clarify what I meant by an empty boat; three batteries, 20 gal of diesel, 6 gal of antifreeze in the hot water tank. That roughy totals 400 lb of non-factory stuff on board. Everything, including the cushions are removed. Unless the Perkins 30 diesel weighs a ton, there is still about 2000 pounds hiding somewhere. The boat weighed 14,000 from birth. The mast is not part of the equation (153 lb stripped) , as it is stored separately from the boat. Food for thought...........Since draft measurements for keels are done in salt water, my boat draws more in the fresh water she sails in. If displacement is calculated in salt water, would it then follow that displacement readings would be significantly different for fresh water ?
vacum
Another one of us heard from,the fact that the time and shape of the Elephant and how many peanuts it has devored before the mishapall come into play.The four feet depending on the type of bottom sand or mudwill have to have more force applied then the body if he lands on the bottom standing up ,add this too the weight because the vacum does require additional force. Eningeer
Another one of us heard from,the fact that the time and shape of the Elephant and how many peanuts it has devored before the mishapall come into play.The four feet depending on the type of bottom sand or mudwill have to have more force applied then the body if he lands on the bottom standing up ,add this too the weight because the vacum does require additional force. Eningeer
My head
This whole displacement discussion is making my head hurt. Displacement weight is the weight of the water (liquid) that is displaced when the boat is put into it. It is a calculation of volume times the weight of the liquid, water, salt water, pespi, orange juice, what ever. The boat will float at different levels depending upon the weight of the liquid it is placed in. Water weight approx 7lbs per gal (salt water weights more), a 15000lbs boat will displace approx 2142.85gal of water or 15000lbs of water. When a boat can't displace it weight in a liquid it sinks.
This whole displacement discussion is making my head hurt. Displacement weight is the weight of the water (liquid) that is displaced when the boat is put into it. It is a calculation of volume times the weight of the liquid, water, salt water, pespi, orange juice, what ever. The boat will float at different levels depending upon the weight of the liquid it is placed in. Water weight approx 7lbs per gal (salt water weights more), a 15000lbs boat will displace approx 2142.85gal of water or 15000lbs of water. When a boat can't displace it weight in a liquid it sinks.
Ron
Ron, pretty sure (if I remember my physics lessons properly) that scientifically, the weight of water for this determination is considered to be pure water, like distilled water. In other water, which would have higher densities, the amount of water displaced, would be less in volume, but would weigh the same.
Ron, pretty sure (if I remember my physics lessons properly) that scientifically, the weight of water for this determination is considered to be pure water, like distilled water. In other water, which would have higher densities, the amount of water displaced, would be less in volume, but would weigh the same.
Fun with the question
We've had fun with the question because buoyancy can be a confusing topic. However, the answer to your question was made early on ... displacement weight equals the weight on the crane. There is a discrepancy because either the crane's scale is off, Catalina's specifications are misleading, or there is extra stuff on board that Catalina doesn't include in the spec. Or a combination of all three. I would be interested to know if there is much weight added due to saturation of the fiberglass with water (it couldn't be worth 2,000 pounds, could it?). Also, I wonder if the engine is included in Catalina's specification or not. The difference in density between salt water and fresh water has nothing to do with displacement weight. It just means a boat rides higher in salt water than it does in fresh water because salt water is more dense. That's a difference in the volume of water the boat displaces, not the weight of water. Same weight ... different volume due to different density. You still have a mystery to solve ... HTH, Scott
We've had fun with the question because buoyancy can be a confusing topic. However, the answer to your question was made early on ... displacement weight equals the weight on the crane. There is a discrepancy because either the crane's scale is off, Catalina's specifications are misleading, or there is extra stuff on board that Catalina doesn't include in the spec. Or a combination of all three. I would be interested to know if there is much weight added due to saturation of the fiberglass with water (it couldn't be worth 2,000 pounds, could it?). Also, I wonder if the engine is included in Catalina's specification or not. The difference in density between salt water and fresh water has nothing to do with displacement weight. It just means a boat rides higher in salt water than it does in fresh water because salt water is more dense. That's a difference in the volume of water the boat displaces, not the weight of water. Same weight ... different volume due to different density. You still have a mystery to solve ... HTH, Scott
Elephant?
Somehow, I have a feeling that it has something to do with the elephant. On a serious note, Ron, you should contact the people with Catalina, they may be able to enlighten you on the possibilities for this discrepancy.
Somehow, I have a feeling that it has something to do with the elephant. On a serious note, Ron, you should contact the people with Catalina, they may be able to enlighten you on the possibilities for this discrepancy.
Heavy vs Light
Scott, is that why they call it a "vessel"? Does that mean that I should carry light cream for my morning coffee instead of heavy cream for pouring over my strawberries at night? How much bouyancy does the air in my air horn contribute? How old was the bridge tender? Who's on first?
Scott, is that why they call it a "vessel"? Does that mean that I should carry light cream for my morning coffee instead of heavy cream for pouring over my strawberries at night? How much bouyancy does the air in my air horn contribute? How old was the bridge tender? Who's on first?
Believe it or not, it can, Franklin
Water buoyancy isn't a constant...salt water is more buoyant than fresh...the higher the salt content, the more buoyant the water. A release of certain gasses from beneath the seabed--for instance, methane--directly under a vessel can reduce buoyancy enough to sink it. In fact, some scientists believe that may be the explanation for disappearances of at least some vessels in the "Bermuda Triangle." There are a lot of large and small methane pockets in the seabed beneath the waters off FL and much of the Caribbean. The History Channel has at least one show about some experiments oceanographers have done to prove or disprove whether it can happen...they proved it can. It's almost a certainty that a methane "burp" from the seabead in the English channel was what sank at least one boat there...and has almost sunk others. Those gas "burps" don't stop at the ocean surface, either...large ones can rise thousands of feet into the air and can also change the air's density, which can cause airplanes to drop. It's a fascinating subject.
Water buoyancy isn't a constant...salt water is more buoyant than fresh...the higher the salt content, the more buoyant the water. A release of certain gasses from beneath the seabed--for instance, methane--directly under a vessel can reduce buoyancy enough to sink it. In fact, some scientists believe that may be the explanation for disappearances of at least some vessels in the "Bermuda Triangle." There are a lot of large and small methane pockets in the seabed beneath the waters off FL and much of the Caribbean. The History Channel has at least one show about some experiments oceanographers have done to prove or disprove whether it can happen...they proved it can. It's almost a certainty that a methane "burp" from the seabead in the English channel was what sank at least one boat there...and has almost sunk others. Those gas "burps" don't stop at the ocean surface, either...large ones can rise thousands of feet into the air and can also change the air's density, which can cause airplanes to drop. It's a fascinating subject.
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