Principal Structural Members of a Ship (Basic Safety)
• The Hull
• The Keel
• The Framing
• The Decks
• The BulkheadsThe Principal Structures are
very important to a ship’s
safety. Life, and property
both depends on a ship’s
structure and should never
be taken forgranted.
Regulation 3-1: Structural, mechanical and electrical requirements
In addition to the requirements contained elsewhere in the
present regulations, ships shall be designed, constructed and
maintained in compliance with the structural, mechanical and
electrical requirements of a classification society which is
recognized by the Administration in accordance with the
provisions of regulation XI/ 1, or with applicable national
standards of the Administration which provide an equivalent
level of safety
• The Hull is the main body of ship exclusive of masts,
superstructure and forcastle.
• Also composed of shell plating, framing, deacks,
bulkheads, angle bars and other parts which we can
classify as stiffeners.
• Importance of The Hull
Prevent Ship from breaking into two, even in the
most severe seas.
It withstand water preasure and local loads caused
by heavy equipment, water shipped on deck and dry
• What is A Girder?
A girder is a collective term for
primary supporting members,
usually supporting stiffeners.
•In reality, a ship s really made
up of girders. A ship is primarily
composed of many small girders
which are braced and tied
together to make the framing
The afterpart of the 25-year-old container ship CARLA after breaking
in two during a storm 100 miles off the Azores. The disaster occurred
after the ship's rudder was damaged, leaving her at the mercy of the
heavy seas. The 34-man crew, who took shelter in the stern section,
were all taken off by helicopter.The forward half sank after five days,
but a tug managed to tow the stern section, carrying 1,000 containers,
to Las Palmas. The ship was lengthened 1984, but the vessel's
owners denies that the ship had broken apart along one of the welds.
Regulation 1: Strength of Hull
The Administration shall satisfy itself that the general
structural strength of the hull is sufficient for the draught
corresponding to the free-board assigned. Ships built and
maintained in conformity with the require-ments of a
classification society recognized by the Administration may be
considered to possess adequate strength.
•Common causes of hull
deformation is mostly the
stresses from the external
forces or stress which
caused by the waves from