Each vessel is required to hold a Loadline Certificate. Part of the requirements for this is the permanent marking of loadlines on either side of the hull arounf about midhsips. Permanent marking means that they have to be impressed or welded so that they cannot be removed by normal wear and tear. They should be white or yellow on a dark contrasting back ground. Regulations govern the number and size of these, the main ones are described below.
Danish Load mark
The Load Line Mark shall consist of a ring 300 millimeters (12 inches) in outside diameter and 25 millimeters (1 inch) wide which is intersected by a horizontal line 450 millimeters (18 inches) in length and 25 millimeters (1 inch) in breadth, the upper edge of which passes through the centre of the ring. The centre of the ring shall be placed amidships and at a distance equal to the assigned summer freeboard measured vertically below the upper edge of the deck line
The deck line is a horizontal line 300 millimeters (12 inches) in length and 25 millimeters (1 inch) in breadth. It shall be marked amidships on each side of the ship, and its upper edge shall normally pass through the point where the continuation outwards of the upper surface of the freeboard deck intersects the outer surface of the shell. The location of the reference point and the identification of the freeboard deck is indicated on the International Load Line Certificate (1966). Lines to be used with the Load Line Mark
The lines which indicate the load line shall be horizontal lines 230 millimeters (9 inches) in length and 25 millimeters (1 inch) in breadth which extend forward of, unless expressly provided otherwise, and at right angles to, a vertical line 25 millimeters (1 inch) in breadth marked at a distance 540 millimeters (21 inches) forward of the centre of the ring . Aft of thevertical mark refers to loading in freshwater only. For'd refers to loading in sea water only
The loadline mark consists of the following marks
- The Summer Load Line indicated by the upper edge of the line which passes through the centre of the ring and also by a line marked S.
- The Winter Load Line indicated by the upper edge of a line marked W.
- The Winter North Atlantic Load Line indicated by the upper edge of a line marked WNA.
- The Tropical Load Line indicated by the upper edge of a line marked T.
- The Fresh Water Load Line in summer indicated by the upper edge of a line marked F.
- The Tropical Fresh Water Load Line indicated by the upper edge of a line marked TF