Stress Flashcards
Hogging
stress occurs when the midship area is supported on the crest of a wave while the bow and stern areas are unsupported in the troughs. The tendency is for the ship to bend upwards in the midship area.
Sagging
stress occurs when the bow and stern areas are supported on the crests of two successive waves while the midship area is unsupported in the trough. The tendency is for the ship to bend downward in the midship area.
Racking
At sea, a ship rolls from side to side. The acceleration on the ship’s structure is liable to cause distortion in the transverse section. The greatest effect is under light ship conditions.
Panting
is a stress which occurs at the ends of a vessel due to variations in water pressure on the shell plating as the vessel pitches in a seaway. The effect is accentuated at the bow when making headway.
pounding
Heavy pitching, assisted by heaving, as the whole vessel is lifted in a seaway and then slams down on the water is known as pounding or slamming. This may subject the forepart of the ship to severe blows from the sea. The greatest effect is experienced in the light ship condition.
Parallel Middle Body
The box like structure of the main body of the ship enabling maximum cargo carrying capacity. It also helps in the pushing when tugs are used to assist the vessel in berthing.
Entrance
This part is the fore end of the ship and helps give the box-like mid length a ship shaped structure. Thus the handling of the vessel is enhanced.
Run
This part is the after end of the ship and helps in giving the box-like mid length a ship shaped structure aft. Thus the handling of the vessel is enhanced.