Load Line Regulations for Ships

This article is about the load line.  All of you who are looking to get a job in the Merchant Navy field should know about this.

What is the purpose of load line usage?

The Lord Line Marks introduced by Samuel Plimsoll are also known as Plimsoll Marks.This is localized to amidships.This specifies the legal volume that can be loaded on a ship, especially depending on the type and temperature of the water.To an observer on the ship the water appears to rise or fall against the hull. Temperature affects the level because warm water provides less buoyancy, being less dense than cold water. The salinity of the water also affects the level, fresh water being less dense than salty seawater.

What is requirements of load line marks?

• The purpose of a 'load line' is to ensure that a ship has sufficient freeboard (the height 

from the water line to the main deck) and thus sufficient reserve buoyancy. 

• All commercial ships, other than in exceptional circumstances, have a load line symbol 

painted amidships on each side of the ship. This symbol must also be permanently 

marked, so that if the paint wears off it remains visible. 

• The freeboard of commercial vessels is measured between the lowest point of the 

uppermost continuous deck at side and the waterline and this must not be less than the 

freeboard marked on the Load Line Certificate issued to that ship. 

• The load line makes it easy for anyone to determine if a ship has been overloaded. 

• The exact location of the Load Line is calculated and/or verified by a Classification 

Society and that society issues the relevant certificates.

Below is a diagram of the loadline marks

The letters on the Load line marks have the following meanings:

• TF – Tropical Fresh Water

• F – Fresh Water 

• T – Tropical Load line

• S – Summer Load Line

• W – Winter Load Line

• WNA – Winter North Atlantic 

• Letters may also appear to the sides of the mark indicating the classification society that 

has surveyed the vessel's load line.

Examples

    • AB - American Bureau of Shipping, 

    • LR - Lloyd's Register, 

    • GL - Germanischer Lloyd, 

    • BV - Bureau Veritas, 

    • IR - Indian Register of Shipping, 

    • RI - RegistroItalianoNavale and 

    • NV - Det Norske Veritas. 

• These letters should be approximately 115 millimeters in height and 75 millimeters in 

width. The Load Line Length is referred to during and following load line calculations

Timber Loadline marks

• Certain vessels are assigned Timber Freeboards but before these can be assigned certain 

additional conditions have to be met

• The letters on the Timber Load line marks have the following meanings:

      

        • LTF – Timber Tropical Fresh Water 

        • LF – Timber Fresh Water 

        • LT – Timber Tropical Seawater 

        • LS – Timber Summer Seawater 

        • LW – Timber Winter Seawater 

        • LWNA –Timber Winter North Atlantic

*Then What is the Load Line Mark ?

The Load Line Mark shall consist of a ring 300 millimetres in outside diameter and 25 millimetres wide which is intersected by a horizontal line 450 millimetres in length and 25 millimetres 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.

What is the Freeboard ?

The freeboard assigned is the distance measured vertically downwards amidships from the 

upper edge of the deck line to the upper edge of the related load line

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