How do you fix free surface effect?

How do you fix free surface effect?

The objects such us engine, pumps, machinery,pipping system etc are prevent the moving water and the “shifting of the wedge” . Thus reducing Free Surface Effect by reducing the flooding water that can fill the space.

What will happen to your ship if you have free surface effect?

The free-surface effect can endanger the ship or even lead to a negative metacentric height. When ballasting the vessel, only one transverse pair or a single centerline ballast tank should be filled up.

What is free surface effect formula?

This reduction in metacentric height due to free surface effect can be calculated by the following expression: IL = Area moment of the free surface about the tank’s longitudinal centre line. ∇S = Mass displacement of the ship in sea water.

What are the causes of free surface effect?

Free surface effects are not only caused by partially-filled tanks. They can, for example, also be caused by accumulated water on deck. To enable the water to run off quickly, a vessel should have adequate freeing ports.

What causes a free surface effect?

What is pocketing in free surface effect?

Free Surface Effect can be reduced, to some extent, by creating pocketing. Pocketing occurs when the surface of the liquid contacts the top or bottom of the tank, reducing the breadth (B) of the free surface area. The Free Surface correction will therefore indicate less overall stability than actually exists.

What is a GZ curve?

The curve of statical stability, or GZ curve as it is most commonly referred to, is a graphical representation of the ship’s transverse statical stability.

Why are cruise ships so stable?

Essentially, a cruise ship stays upright because they keep all of the heaviest equipment below deck. This has the effect of keeping a low center of gravity. In addition, the shape of a cruise ship’s hull is wide and rounded, which helps it move through the ocean smoothly and with minimal drag.

Where can I find free surface moments?

What is Free Surface Moments?

  1. If the value of I is multiplied by the liquid density then a value of ‘Free Surface Moments’ (FSM’s) (t-m) is obtained.
  2. Consider the previous Free Surface Effect formula:
  3. Therefore:
  4. Since:

What are the factors affecting free surface?


  • FSE increases with increased length and width of compartment.
  • FSE increases when displacement decreases (de-ballasting)
  • FSE is independent of the depth of the liquid.