Sagging
Sagging is a nautical term and can best be translated as "sagging".
It describes the bending load that acts on the structure of a ship when it runs alongside the surf in a storm and the wavelength roughly corresponds to that of the ship. If the stern and bow are at the same time in the wave crest, the buoyancy of the water increases locally , while in the middle of the ship, in the trough of the wave , the buoyancy decreases significantly. This results in bending forces which lead to tensile forces in the area of the keel and to compressive forces in the area of the deck . In the case of riveted hulls, rivets can shear off the frames . As a result, an immediate structural failure occurs, in which the deck and keel usually break at the same time in quick succession and the ship begins to sink.
This is differentiated from hogging , which describes the opposite condition: the stern and bow are in the trough of the waves and the middle of the ship on the crest of the waves.
Factors in this disaster scenario are the combination of the relationship between the wavelength and the length of the ship, the height of the wave, the current course in relation to the direction of the wave, the distribution of the cargo and construction defects.
See also
literature
- Age does not protect against stupidity. Gesamtverband der Deutschen Versicherungswirtschaft eV, May 1996, p. 10 ( PDF file; 2.5 MB ).