Ships frequently encounter extremes of weather and constantly undergo structural strains and stresses in their daily operation. It is vital that they are designed and built to withstand the marine environment’s very worst environmental and operational trials. Careful life-time care is also crucial to preserve their structural integrity. Classification societies are non-governmental organisations that set and apply design and construction rules to establish standards for the structural strength of the ship’s hull and its appendages, and the suitability of the propulsion and steering systems, power generation and those other features and auxiliary systems which have been built into the ship to assist in its operation. The classification of a vessel is based on the assumption that the vessel is loaded, operated and maintained in a proper manner by competent and qualified crew or operating personnel. Ship classification provides a point of reference on ship safety and reliability to shipbuilders, ship repairers, shipbrokers, charterers, flag administrations, insurers and the financial community. On delivery of a ship, classification societies institute a programme of frequent inspections and Surveys during the working lives of ships, to check that their structures remain safe.
Many nations have their own classification societies working closely with the Flag State of that country. However, the ten leading societies are all members of the London-based International Association of Classification Societies (IACS). Many Marine Insurance underwriters insist that vessels be classed by an IACS member as a condition of cover