The maximum angle of heel that a ship can withstand depends on various factors, including the vessel's design, stability, and the external forces acting on it. Here are some ways to determine the maximum angle of heel for a ship:
- The angle of heel due to the combined effect of crowding, wind pressure, and centrifugal force should not exceed 12° in calculations[1].
- The curve of static stability is a plot between the righting lever and angle of heel, and the maximum righting lever (GZMAX), represented by point ‘B’ in the graph, is proportional to the largest static heeling moment that is required to bring the ship back to its upright position[2].
- The area under the GZ curve, up to a given angle, is proportional to the energy needed to heel the ship to that angle[3].
- The maximum righting arm is the angle of heel at which the maximum righting lever occurs[5].
- The estimated maximum angle of heel before equalization must be approved on a vessel required to survive assumed damage[5].
- The vessel's metacentric height (GM) must be at least 2 inches (5 cm) when the vessel is in the upright position[5].
- The maximum righting arm should occur at an angle of heel preferably exceeding 30° but not less than 25° [4].
- The final angle of equilibrium must not exceed 7 degrees after equalization on a vessel required to survive assumed damage with a longitudinal extent of 10 feet (3 meters) plus 0.03L, and it must not exceed 15 degrees after equalization on a vessel required to survive assumed damage with a longitudinal extent of 20 feet (6.1 meters) plus 0.04L[5].
In summary, the maximum angle of heel that a ship can withstand depends on various factors, and there is no single value that applies to all vessels. The angle of heel is limited by the vessel's stability, design, and the external forces acting on it. The maximum angle of heel can be determined by analyzing the vessel's stability and the external forces acting on it.
Citations:
[1] Heel Angle - an overview | ScienceDirect Topics https://www.sciencedirect.com/topics/engineering/heel-angle
[2] Ship Stability - Understanding Curves of Static Stability - Marine Insight https://www.marineinsight.com/naval-architecture/ship-stability-understanding-curves-static-stability/
[3] Dynamical Stability - an overview | ScienceDirect Topics https://www.sciencedirect.com/topics/engineering/dynamical-stability
[4] Wind speed vs angle of heel | Boat Design Net https://www.boatdesign.net/threads/wind-speed-vs-angle-of-heel.45588/
[5] [PDF] Chapter 2 - Review of Intact Statical Stability https://www.usna.edu/NAOE/_files/documents/Courses/EN455/EN455_Chapter2.pdf
[6] Stability at Large angles of heel - YouTube https://youtube.com/watch?v=nka4RqCfpdI
By Perplexity at https://www.perplexity.ai/search/6bfaf105-6e8e-469f-aad9-8e677c9fd97f?s=m
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