C.G OF Gravity

one condition of cg of vessel is operating.

second condtion of vessel is cg is empty condition.

third condition is hydro test location of cg..

Higher, lower and maybe somewhere in between.

It changes with fluid level.

Do you know what the center of gravity really means???????

Get a life.

how generally weight of operating condtion is higher than the empty and hydrotest weight is much higher than all. ok than we assume that cg of if operating fuild density less than one

CG OF WATER Hysro test > cg of operating> cg of empty

Is this right???????????????

I agree. The question is poorly stated. Presumably this vessel has a bottom; does it also have a top? It sounded to me at first reading that he was comparing an empty vessel to an MT vessel.

The answers have covered the possibilities. Perhaps you can obtain the answer you want by standing back 50 yards (or maybe you use meters) and throwing a dart to see where it hits.

Yes, still true. Just do the arithmetic for calculating the CG.

It depends. A Marine Architect (basically a ship designer) locally would be the best person to talk to.

The centre of gravity and the centre of rotation of a ship determine its stability at sea, as does its shape.

There is a section in Kempe's Engineers' Yearbook on the stability of ships, whoich might make interesting bedtime reading. Try and borrow a copy.

Other than that, try the local Reference Library. There is a fair selection of books on ship design in Chelmsford Library, for example.

I think he means a tank rather than a tanker.

In the absence of knowing, through the absence of contextual information, what is a poor reader supposed to do [rhetorical question - NNTR]? <sigh>

#1↑ sort of cleared up that ambiguity.

Center of gravity depend on weight distribution. It shifts towards the weight is added. Generally below the half of the height of a balanced/equilbrumed vessel

Could be either, presuming you mean a vessel as a container, not a ship. When the vessel is near empty, its CG is higher than the CG of the liquid. As the liquid fills the vessel, the liquid's CG may rise above the CG of the empty vessel, giving a higher combined CG.

It depends on how you load the vessel but, if the vessel is a boat or ship, keep the C of G below the metacentre.

It all depend where the load is placed. If it is placed above the cg it will make

the cg higher, and if placed lower, it will lower the cg. (what do you think?)

jt

A young boy and his dad went out fishing one fine morning. After a few quiet hours out in the boat, the boy became curious about the world around him. He looked up at his dad and asked "How do fish breath under water?"His dad thought about it for a moment, then replied, "I really don't know, son."The boy sat quietly for another moment, then turned back to his dad and asked, "How does our boat float on the water?"Once again his dad replied, "Don't know, son."Pondering his thoughts again, a short while later, the boy asks "Why is the sky blue?"Again, his dad replied. "Don't know, son. "The inquisitive boy, worried he was annoying his father, asks this time "Dad, do you mind that I'm asking you all of these questions?"

"Of course not son." replied his dad, "How else are you ever going to learn anything?"

If you are talking about a boat/ship, I would be a little concerned with your last point "third condition is hydro test location of CG."

I am pretty sure that filling any part of the vessel with water other than an area designated as capable of holding and transporting fluids to find the CG would be catastrophically interesting and well worth observing from a distance.

On the other hand; If you are talking about testing a forklift for CG, using a hydro test to find the CG might be challanging and a little messy so I would recommend using a solid mass for testing instead.

The point is:

Each "vessel' requires different test methods to identify the CG depending on what type of cargo is being transported. (people, steel plate, barrels, liquids, animals, etc.)

Yes in some cases such as with a cargo ship and/or a water truck the movement of the vessel could affect the CG because despite the use of internal baffles, the fluid level cannot maintain stablity during violent change of direction conditions.

In the case of solid cargo, an unsecured load will definitely affect the CG.

based on other questions from the same poster one has to assume the vessel referred to is a container, not a vehicle or ship-therefor the answer is higher as the CG of the empty container would be just above the floor point- if a holding device were added with rotational capability (Elastic clamp) then as fluids were added the holding device would have to be elevated on the container to prevent rotation

Not Always / Perhaps.

When empty, the CG is at the center of the vessel.
When full, such as for hydrotest, the CG is again at the center of the vessel.

Starting with an empty vessel, as fluid is added, the CG drops and then rises again. The graph would be a curve, with the operating level somewhere along it.

Dear Friend,

It is not necessarily be at lower level. It depends upon the height of the vessel also apart from liquid level.

DHAYANANDHAN.S

" Is center of gravity of of vessel always lower / higher than the empty condition? "

Sort answer - NO.

If the load (whatever it is) is equally placed around the cg then it will have no effect.

(If the load CG is "centered" exactly around the container CG then it will not alter the CG of the whole unit.)

Now in the real world: if the load is positioned above the CG of the container (whatever it is) - then the CG of the whole unit, load and container will become higher.

Equally, if the load is positioned below the container CG then, the CG of the whole will be lowered.

But the answer to the OP is.. Not necessarily, No. but in the real world it likely will be.

jt.

An old lady bought a self assembly wardrobe, and days later rang the store complaining that it fell apart
when the bus went by the house.
The store sent a technician to help her and check-up on the wardrobe.

After making sure it was re-assembled correctly, the lady said, "you'll see! It will fall apart when a bus goes by."
Thinking a bus will be arriving soon and, humoring the lady, he said, "I'll watch what happens when the bus comes from inside" and got in. The lady said thank you, "I'll go down stairs and make us a cup of tea."

While making the tea her husband came home and went upstairs; on opening the wardrobe, he said to the man inside,
"What the devil are you doing here?!"
He replied, "you're not going to believe this, but I'm waiting for a bus."