Ship Stability and Dynamics-Part I — Lesson 7

This lesson covers the concept of ship stability and dynamics, focusing on the motion of the metacenter and the assumptions made in the development of mathematical theories related to ship heeling. It discusses the case of deck edge immersion and the implications of volume differences between the side immersed and the side emerged. The lesson also introduces the concept of dynamic similarity and explains how the work done to heel a ship, known as dynamical stability, can be calculated. It further discusses the rules related to dynamical stability, GZ curve, and GM for ship design. The lesson concludes with an explanation of the phenomenon of lolling in ships.

Key Takeaways:
- The displacement del is assumed to remain constant in the development of mathematical theories related to ship heeling.
- The concept of dynamic similarity involves calculating the work done to heel a ship, known as dynamical stability.
- The area under the GZ curve represents the dynamical stability of a ship.
- Certain rules related to dynamical stability, GZ curve, and GM must be followed in ship design.
- The phenomenon of lolling in ships occurs when a ship remains at a constant angle of heel, known as the angle of loll.

Video Highlights

0:22 – Explanation of the motion of the Meta center and how the metacenter moves along with the heeling.

0:32 – Discussion on the assumption that the displacement del is always remaining constant in the development of mathematical theories

13:30 – Introduction to the concept of dynamic similarity and how it relates to the motion of a ship

28:55 – Discussion on the concept of dynamical stability and how it is calculated using the area under the GZ curve

42:54 – Explanation of the rules related to dynamical stability, GZ, and GM that need to be followed in ship design

45.26 – Discussion on the phenomenon of Condition for stability