ShipShip Terminology Terminology

Lec. 1Lec. 1Dr. Arwa HusseinDr. Arwa Hussein

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

Port :The left side of the ship when looking forward

Starboard : The right side of the ship when looking forward

• Design Waterline (DWL) or Load Waterline (LWL) : The waterline at which the ship

will float when loaded to its designed draught.

• Forward Perpendicular (FP) : The vertical line at the point of intersection of the LWL

and the forward end of the immersed part of the ship’s hull.

• After Perpendicular (AP) : The vertical line at the point of intersection of the LWL and

the centerline of the rudderstock.

• Midships () : The point midway between the forward and after perpendiculars.

• Length of Waterline (LWL) : The waterline at which the ship will float

when fully loaded .

• Length Overall (L OA) : The total length of the ship from one end to the

other, including bow and stern overhangs.

• Length Between Perpendiculars (L BP) : The distance measured parallel

to the base at the level of the design waterline from the after perpendicular

to the forward perpendicular.

• or other designated point on the stern.

• Moulded Beam or Breadth (B) : The distance from the inside of plating

on one side to a similar point on the other side measured at the broadest

part of the ship.

• Deck Camber : The rise of the deck of the ship in going from the side to the

centre. In older ships the camber curve used to be parabolic but in modern ships

straight line camber curves are used or there may be no camber at all on decks.

• Bilge Radius : The radius of the circular arc forming the bilge.

• Flat of Keel (Half Siding) : The width of flat bottom plating on each side of the

centre girder.

• Deadrise (Rise of Floor) : The amount by which the line of the outer bottom

plating amidships rises above the baseline. Therefore, it is the difference in height

between the baseline and the point where the straight line through the bottom flat

surface intersects the vertical line through the side of the moulded surface at its

widest point.

• Parallel Middle Body : The portion of the ship over which the midship section

remains unchanged. In this part of the ship water lines and buttocks have no

curvature; that is, all the fore and aft lines are

Form Coefficient Form Coefficient

Block Coefficient Block Coefficient

Prismatic CoefficientPrismatic Coefficient

Mid ship section Mid ship section Coefficient Coefficient

Mid ship section and water plane area Mid ship section and water plane area coefficientscoefficients

End of LectureEnd of Lecture