HULL:
The structural body of a ship including shell plating,
framing, decks and bulkheads.
AFTERBODY :
That portion of a ship’s hull abaft midships.
FOREBODY:
That portion of a ship’s hull forward midships.
BOW :
The forward of the ship
STERN :
The after end of the ship
The left side of the ship when looking forward
STARBOARD :
The right side of the ship when looking forward
AFTER PERPENDICULAR (A.P.)
A perpendicular drawn to the waterline at the point
where the aft side of the rudder post meets the summer load line. Where no
rudder post is fitted it is taken as the centre line of the rudder stock.
FORWARD PERPENDICULAR (F.P.):
A perpendicular drawn to the waterline at the point where the foreside of
the stem meets the summer load line.
LENGTH BETWEEN PERPENDICULAR
(L.P.P. / L.B.P.):
The length between the forward and the aft perpendiculars measured along
the summer load line.
AMIDSHIPS:
A point midway between the after and forward perpendiculars
LENGTH OVERALL (L.O.A.):
Length of the vessel taken over all extremities.
BASE LINE:
A horizontal line drawn at the top of the keel plate. All vertical moulded
dimensions
are measured relative to this line
MOULDED BEAM:
Measured at the midship section is the maximum moulded breadth of the ship
MOULDED DRAFT/ DRAUGHT:
The distance from the bottom of the keel to the waterline. The load draft
is the maximum draft to which a vessel may be loaded
MOULDED DEPTH:
Measured from the base line to the heel of the upper deck beam at the ship’s
side amidships.
SHEER:
Curvature of decks in the longitudinal direction. Measured as the height of
deck at side at any point above the height of deck at side amidships
CAMBER / ROUND OF BEAM:
Curvature of decks in the transverse direction. Measured as the height of
deck above the height of deck at side
RISE OF FLOOR / DEADRISE:
The rise of the bottom shell plating line above the base line. This rise is
measured at the line of moulded beam
HALF SLIDING OF KEEL:
The horizontal flat portion of the bottom shell measured to port or starboard
of the ship’s longitudinal centre line.
This is useful dimension to know when dry-docking.
TUMBLE HOME:
The inward curvature of the side shell above the summer load line.
FREEBOARD:
The vertical distance measured from the waterline to the top of the deck plating
at the side of the deck amidships. Normally exposed to weather and sea.
FLARE:
The outward curvature of the side shell above the waterline. It promotes dryness
and is therefore associated with the fore end of ship
EXTREME BEAM:
The maximum beam taken over all extremities.
EXTREME DRAFT:
Taken from the lowest point of keel to the summer load line. Draft marks
represent extreme drafts.
EXTREME DEPTH:
Depth of vessel at ship’s side from upper deck to lowest point of keel.
HALF BREADTH:
Since a ship’s hull is symmetrical aďout the longitudinal centre line,
often only the half beam or half breadth at any section is given.
SCANTLING:
The dimensions of the structural items of a ship, e.g.
frames, girders, plating , etc.
INTERCOSTAL
Composed of separate parts, non-continuous.
CENTER
OF FLOATATION:
It is the center of the waterplane area and is the axis about which a ship
changes trim.
CENTER OF BUOYANCY:
It is the center of the underwater volume of the ship where the force of
buoyancy acts.
CENTER OF GRAVITY:
It is the point at which the whole weight of the object may be regarded as
acting. If the object is suspended from this point, it will remain balanced and
not tilt.
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