1.1 Ship Dimensions - Length
Longitudinal Merchant Ship Dimensions - Length
A ship’s dimensions can be measured in length, depth and width. Every commercial vessel has a list of exact measurements and dimensions based on the building plans and load capacity.
Longitudinal dimensions
Depending on the points of reference, there are different ways of expressing the length of a vessel :
Length overall (LOA): the length between the extreme points of the ship, between the aft and the stern. The LOA is a non-variable measurement.
Length at waterline (LWL): The distance between the extreme forward and aft points of the ship where it intersects the waterline. The LWL is a variable measurement depending on the load of the vessel.
Length between perpendiculars (LBP): the length between the forward and aft perpendiculars. The LBP is an invariable design measurement based on the summer waterline (SWL).
Forward perpendicular (FP): a perpendicular line to the waterline, drawn at the intersection of the stem (fore part of the ship) and the summer waterline.
Aft perpendicular (AP): a perpendicular to the waterline, drawn at the intersection of the rudder stock (the rudder shaft) and the summer waterline.
