Ship classification

A classification society is a non-governmental organization that establishes and maintains technical standards for the construction and operation of ships and offshore structures. The society will also validate that construction is according to these standards and carry out regular surveys in service to ensure compliance with the standards.

To avoid liability, they explicitly take no responsibility for the safety, fitness for purpose, or seaworthiness of the ship.

Classification societies set technical rules based on experience and research, confirm that designs and calculations meet these rules, survey ships and structures during the process of construction and commissioning, and periodically survey vessels to ensure that they continue to meet the rules. Classification societies are also responsible for classing oil platforms, other offshore structures, and submarines. This survey process covers diesel engines, important shipboard pumps and other vital machinery.

Classification surveyors inspect ships to make sure that the ship, its components and machinery are built and maintained according to the standards required for their class

In the second half of the 18th century, London merchants, shipowners, and captains often gathered at Edward Lloyds’ coffee house to gossip and make deals including sharing the risks and rewards of individual voyages. This became known as underwriting after the practice of signing one's name to the bottom of a document pledging to make good a portion of the losses if the ship didn’t make it in return for a portion of the profits. It did not take long to realize that the underwriters needed a way of assessing the quality of the ships that they were being asked to insure. In 1760, the Register Society was formed — the first classification society and the one which would subsequently become Lloyd's Register — to publish an annual register of ships. This publication attempted to classify the condition of the ship’s hull and equipment. At that time, an attempt was made to classify the condition of each ship on an annual basis. The condition of the hull was classified A, E, I, O or U, according to the state of its construction and its adjudged continuing soundness (or lack thereof). Equipment was G, M, or B: simply, good, middling or bad. In time, G, M and B were replaced by 1, 2 and 3, which is the origin of the well-known expression 'A1', meaning 'first or highest class'. The purpose of this system was not to assess safety, fitness for purpose or seaworthiness of the ship. It was to evaluate risk.

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