Raising Shipwreck with Buoyancy Balloons - Calculations Needed?

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SUMMARY

To raise a shipwreck using buoyancy balloons, one must calculate the total weight of the ship, including its mass and any trapped water. However, the weight of the water above the ship does not need to be included in the lifting force calculation, as the pressure forces acting on the ship are balanced. The buoyancy of the ship's metal structure must be subtracted from the lifting force requirement, while the trapped water inside the ship does not affect the lifting force since it has its own buoyancy. Proper consideration of these factors is essential for accurate calculations.

PREREQUISITES
  • Understanding of buoyancy principles
  • Knowledge of pressure forces in fluid mechanics
  • Familiarity with the concept of net forces
  • Basic calculations involving mass and volume
NEXT STEPS
  • Research Archimedes' Principle and its application in buoyancy calculations
  • Study fluid dynamics, focusing on pressure forces and their effects
  • Learn about the properties of different materials, particularly their buoyancy
  • Explore practical applications of buoyancy balloons in marine salvage operations
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Marine engineers, salvage operators, and anyone involved in underwater recovery operations will benefit from this discussion, particularly those seeking to understand the calculations necessary for raising submerged objects.

gloo
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If there is a shipwreck that i am trying to raise and i try to calculate the number of ballons to attach to the ship to raise it to the surface, do i have to just the weight of the ship given it's mass (all the steel it's made of; all the stuff inside...) and the mass of the water trapped in it? Assume it's a rectangular ship sitting upright - don't i need to calculate the weight of all the water directly above it all the way to the surface? That weighs down on the ship doesn't it?
 
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gloo said:
If there is a shipwreck that i am trying to raise and i try to calculate the number of ballons to attach to the ship to raise it to the surface, do i have to just the weight of the ship given it's mass (all the steel it's made of; all the stuff inside...) and the mass of the water trapped in it? Assume it's a rectangular ship sitting upright - don't i need to calculate the weight of all the water directly above it all the way to the surface? That weighs down on the ship doesn't it?

The water above the ship exerts a pressure on it, that is true, but the additional pressure force pushing it down is canceled by an additional pressure force acting up on the bottom of the ship. By this I mean that the net effect of the pressure force on the ship is the same no matter how deep it is. You can disregard it, except for the effect it will have on the volume of the balloons.

There will also be a viscous force from the surrounding water acting downward when the ship starts to rise, but this can only slow it, not stop it from rising.
 
Be careful about the water trapped inside it - since you aren't lifting the ship above the water, the water inside does not affect the lifting force requirement. It has its own buoyancy.

You also need to subtract the buoyancy of the metal in the ship from the lifting force requirement.
 
To be clear, you can include the water in the calculation, but as long as you include both the additional weight and additional volume, it will make to difference.
 

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