The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code), adopted by resolution MSC.5(48),has been mandatory under SOLAS chapter VII since 1 July 1986. The IGC Code applies to ships regardless of their size, including those of less than 500 gross tonnage, engaged in carriage of liquefied gases having a vapour pressure exceeding 2.8 bar absolute at a temperature of 37.8°C, and certain other substances listed in chapter 19 of the Code. The aim of the Code is to provide an international standard for the safe carriage by sea in bulk of liquefied gases and the substances listed in chapter 19, by prescribing the design and construction standards of ships involved in such carriage and the equipment they should carry so as to minimize the risk to the ship, to its crew and to the environment, having regard to the nature of the products involved.
The basic philosophy is one of ship types related to the hazards of the products covered by these codes, each of which may have one or more hazard properties. A further possible hazard may arise owing to the products being transported under cryogenic (refrigerated) or pressure conditions.
Severe collisions or strandings could lead to cargo tank damage and uncontrolled release of the product. Such release could result in evaporation and dispersion of the product and, in some cases, could cause brittle fracture of the ship's hull. The requirements in the codes are intended to minimize these risks as far as is practicable, based upon present knowledge and technology.
Throughout the development of the Code it was recognized that it must be based upon sound naval architectural and engineering principles and the best understanding available as to the hazards of the various products covered; furthermore that gas carrier design technology is not only a complex technology but is rapidly evolving and that the Code should not remain static. Therefore, IGC Code is kept under review, taking into account experience and technological development. The latest comprehensive amendments of the IGC Code were adopted by resolution MSC.370(93), expected to enter into force on 1 July 2016.
Code for the Construction Equipment of Ships Carrying Liquefied Gases in Bulk (GC Code) and Code for Existing Ships Carrying Liquefied Gases in Bulk (EGC Code)
Gas carriers constructed before 1 July 1986 and after 31 October 1976 should comply with the requirements of the Code for the Construction Equipment of Ships Carrying Liquefied Gases in Bulk (GC Code), while gas carriers that had already been trading prior to the application of the GC Code should comply with the requirements of the Code for Existing Ships Carrying Liquefied Gases in Bulk.