Standard Terminology Flashcards
Define Aft perpendicular
As imaginary vertical line at the intersection of the after part of the rudder post or centreline of the rudder stock and the Summer Load waterline
Define Amidships
The mid-length position between the after and forward perpendiculars.
Define Beam
The horizontal distance measured across the vessel. (Width)
define camber
The downward curvature of the deck in the transverse plane – it is the difference in the height of the deck at the fore and aft centreline, and the height of the deck port and starboard.
define deadweight
The weight of the cargo, fuel, stores, fresh water, passengers, etc that the ship is carrying at any given draft. Deadweight is the difference between the displacement and the lightweight.
define displacement
The weight of the ship plus its contents, measures in tonnes, for any specific draft.
define entrance
The gradual increase in breadth(width) from stem(Bow) to a mid-length position.
define extreme breadth
The maximum beam(Width) of the ship between the extreme points port and starboard.
define extreme draft
The vertical distance between the waterline and the deepest point of the keel.
define extreme depth
The greatest vertical distance measured from the uppermost continuous deck to the deepest point at the keel.
define flare
The outward curvature of the shell plating above the waterline, at the forward end. A measure of the difference in breadth at waterline, and breadth at deck level.
define forward perpendicular
An imaginary vertical line at the intersection of the stem and the Summer Load Waterline.
define freeboard
The vertical distance measured between the upper edge of the Summer Loadline and the upper edge of the deck line.
length between perpendiculars
The distance between the after and forward perpendiculars at the summer draft marks.
length overall
The horizontal distance between the forward and after extremities of the ship.
lightweight
The weight of the empty ship plus the weight of the water in her boilers, measured in tonnes.
lloyds length
The ship’s length as used by Lloyds Register for calculating allowances for freeboard and other scantlings – it is between 96% - 97% of the LOA.
moulded dimensions
The measurements taken inside the shell plating, i.e. the dimensions of the ship’s ‘skeleton’ taken from frame to frame and stempost to sternpost.
air draft
Air draft of a ship refers to the distance from the waterline to the highest point on the ship that is not permanently attached.
trim
In maritime terms refers to the difference in the ship’s draft between the forward (bow) and aft (stern) parts of the vessel. Essentially, it’s about how level the ship is sitting in the water:
-If the bow is lower than the stern, the ship is said to have a “forward trim” or is “down by the head.”
-Conversely, if the stern is lower, it’s known as an “aft trim” or “down by the stern.”
even keel
trim is 0
full and down
a term used in the shipping industry to describe a condition where a ship’s cargo holds are completely filled (full) and the weight of the cargo is such that the ship is sitting low in the water (down) at or near its maximum draft. This indicates that the vessel is fully loaded and has utilized its maximum allowable cargo capacity.
trimmed by the head or down
“Trimmed by the head” is a condition where a ship is sitting lower in the water at the bow than at the stern.
trimmed by stern
refers to a ship that is sitting lower in the water at the stern (the rear part of the ship) than at the bow (the front part).
