Inspection of aged ships and offshore structures

Ch.13 of the book "Condition assessment of aged structures", edited by Prof. Jeom Paik and Robert Melchers. Reasons for inspection and inspection events are described, highlighting peculiarities that make ship and offshore structures ones of the most challenging to inspect. Actually, ships are the largest structures ever built moving all around the world: this makes inspections different from land based structures for a number of reasons. Factors influencing inspection performances are then commented in detail, recognising that it is not always possible to quantify the reliability of the complex process called “detection and sizing of degradation”, depending indeed on many parameters not always easy to be defined quantitatively. However, it would be enviable to attempt to do so in the as far as possible rational way. Current inspection practice is examined from the viewpoint of surveyors, who have to follow different instructions depending on their role but mainly relying on their experience. Methods for detection and sizing of degradation are discussed: traditional methods and future trends are presented for corrosion, fracture and mechanical damages.