Classification Surveys

IMO

A classification survey is a visual examination that normally consists of: • an overall examination of the items identified in the Rules for survey; • detailed checks of selected parts, on a sampling basis; • witnessing tests, measurements and trials where applicable. When a surveyor identifies corrosion, structural defects or damage to hull, machinery and/or piece of equipment which, based on the Society’s Rules and in the opinion of the surveyor, affects the ship’s class, remedial measures and/or appropriate recommendations/conditions of class are specified in order to retain class. ‘Recommendation’ and ‘condition of class’ are different terms used by IACS Societies for the same thing i.e. requirements to the effect that specific measures, repairs, request for surveys etc., are to be carried out within a specified time limit in order to retain class. Each classed vessel is subject to a specified programme of periodic surveys after delivery. These are based on a five-year cycle and consist of annual surveys, an intermediate survey and a class renewal/special survey (held every 5 years). The rigour of each specified survey increases with the age of the vessel. The class renewal surveys/special surveys include extensive in-water and, in most cases, out-of-water examinations to verify that the structure, main and essential auxiliary machinery, systems and equipment of the ship remain in a condition which satisfies the relevant Rules. The examination of the hull is supplemented, when specified, by ultrasonic thickness measurements and the witnessing of tests as specified in the Rules and as deemed necessary by the attending surveyor. The survey is intended to assess whether the structural integrity remains in conformance with the standards contained in the relevant Rules and to identify areas that exhibit substantial corrosion, significant deformation, fractures, damages or other structural deterioration. Depending upon the age, size, type and condition of the vessel, the renewal/special survey may take several weeks to complete. The intermediate survey (held approximately half way between special surveys) includes examinations and checks as specified in the Rules to determine whether the ship remains in a general condition which satisfies the Rule requirements. According to the type and age of the ship, drydocking may be required and the examinations of the hull may be supplemented by ultrasonic thickness measurements as specified in the Rules and where deemed necessary by the attending surveyor. At the time of annual surveys, the ship is generally examined. The survey includes an external general inspection of the hull, equipment and machinery of the ship and some witnessing of tests, so far as is necessary and practical in order to determine whether the ship remains in a general condition which satisfies the Rule requirements. Older ships of certain types may also be subject to a general examination of some specified internal areas of the hull. Depending upon the age, size, type and condition of the vessel, an annual survey may take from several hours to a few days to complete

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