A Review of Nondestructive Examination Methods for New-building Ships Undergoing Classification Society Survey

Abstract

Classification societies require ship manufacturers to perform non-destructive examination of ship weldments in order to ensure the welding quality of new-built ships. Ships can contain hundreds of kilometres of weld lines and 100% inspection of all welded connections is not feasible. Hence, a limited number of weldments are specified by rules of Classification Societies to be inspected for this purpose. There is a variation between the rules and guidelines used by different Classification Societies in terms of both philosophy and implementation which results in significant discrepancy in the prescribed checkpoints numbers and their locations. In this paper, relevant sections of the rules of mainstream IACS (International Association of Classification Societies) members are studied and potential ways of improving them are discussed. The authors have endeavoured to make this study as comprehensive as possible. However, given the challenges of covering every single aspect and variable related to non-destructive examination (NDE) in the Classification Societies' rules and guidelines reviewed here, the authors can only attempt to cover the key features.

Visual Corrosion Inspection, Evaluation, and Repair Procedure for Ship Tanks Navigating the Mediterranean Sea

“…The visual inspection, serving as a key component of the assessment process, ensures that the vessel meets the rigorous standards required for safe and efficient maritime operations, reinforcing its status as a reliable presence in the maritime landscape. Considering that each classification society has its own inspection regulations [24] [8], this inspection was performed in accordance with the Spanish Legislation Royal Decree 1837/2000 [23].…”

Review of Fatigue Assessment Approaches for Welded Marine Joints and Structures

“…A typical NDT inspection plan [18]. Some fatigue cracks have been detected in the ship structures within a few years of their service life.…”

“…An overview of weld quality control and assurance of welded structures subjected to fatigue loading was provided by Stenberg et al [16] The ships can contain hundreds of kilometers of weld lines, so only a limited number of welded joints can be inspected, and the Classification Societies specify a number of checkpoints for the inspection. Thus, a risk-based inspection approach could be applied [18]. Figure 11 shows a typical NDT inspection plan of a ship with the checkpoints highlighted in green.…”

A fracture mechanics framework for optimising design and inspection of offshore wind turbine support structures against fatigue failure

“…A structure is inspected during construction for quality control purposes. Choice of the NDT method varies between fabrication yards, but as a general rule, all weldments are visually inspected and may be complemented by inspection of a limited number of checkpoints using more reliable NDT techniques on a sampling basis (Amirafshari et al, 2018). If no significant flaws are detected, the initial flaw size is set at an assumed value a 0 , which corresponds to the largest flaw that might be missed by NDT.…”