What is load line survey and load line certificate?

The load line survey, also known as a Load Line Certificate survey is a type of survey conducted on ships to determine and verify their compliance with the International Convention on Load Lines (ICLL). The load line survey ensures that the ship meets the required standards for buoyancy, stability, and safety by establishing the ship's freeboard marks.

The International Convention on Load Lines establishes rules and regulations for determining the minimum freeboard of ships based on their type, size, construction, and intended operations. Freeboard refers to the vertical distance between the waterline and the uppermost continuous deck exposed to weather.

During a load line survey, a qualified surveyor, often appointed by the ship's classification society, inspects the ship's structure, stability calculations, and documentation to assess its compliance with the load line requirements. The survey includes the following key aspects:

1. Verification of Documentation: The surveyor checks the ship's documentation, including the stability book, hydrostatic curves, plans, and certificates, to ensure they are in accordance with the load line regulations.
2. Measurement and Calculation of Freeboard: The surveyor takes measurements of the ship's structure and determines the ship's freeboard based on the load line regulations. This includes measuring the bow and stern drafts, determining the ship's lightweight, and calculating the required freeboard based on its assigned load line zones.
3. Inspection of Load Line Markings: The surveyor checks the ship's load line markings, including the Plimsoll mark and the load line disc or line, to ensure they are accurately placed and visible. These markings indicate the ship's assigned load line and provide information on the ship's maximum permissible draft based on its assigned freeboard.
4. Examination of Stability and Subdivision: The surveyor reviews the ship's stability calculations and subdivision arrangements to ensure they meet the requirements for maintaining stability and preventing excessive flooding in case of damage.
5. Examination of Watertight Integrity: The surveyor inspects the ship's watertight compartments, doors, hatches, and other openings to verify their integrity and ensure they are capable of preventing the ingress of water into critical areas.

Upon successful completion of the load line survey, a Load Line Certificate is issued to the ship, confirming its compliance with the load line regulations. The Load Line Certificate specifies the ship's load line zones, marks, and other relevant information.

Load line surveys are conducted periodically, typically every five years, or whenever there are significant modifications or alterations to the ship that could affect its stability or load line compliance. These surveys help ensure the safety and seaworthiness of the ship by determining its proper loading limits and maintaining adequate reserve buoyancy to withstand various operating conditions and environments.