UNDERWATER SHIP HULL INSPECTION

Abstract

ABSTRACTNavy managers need accurate information in order to make cost effective decisions. In the case of ship hull repair or maintenance decisions, the information can often be obtained through Nondestructive Examination (NDE) of the hull. Newly developed NDE hardware and techniques now permit many inspections to be performed on waterborne ships, thus avoiding the cost and/or necessity of dry‐docking for inspection. These underwater inspections are also used to forecast accurately hull work requirements for upcoming planned overhauls, to plan and to evaluate underwater repair work, and to monitor the status of known defects in hull structures.Underwater NDE techniques being developed at the Naval Coastal System Center (NCSC) under Naval Sea Systems Command (NAVSEA) sponsorship include stereo photography, magnetic particle inspection, ultrasonic thickness gaging and flaw detection, and electromagnetic weld inspection. Individual techniques are currently in various stages of qualification as Navy approved procedures.Throughout the development process at NCSC, field work on Navy ship hulls has been undertaken in order to assure the techniques' operational effectiveness, accuracy, reliability, and utility to Navy managers. Thus, a substantial body of real world data exists.This paper describes procedures which are being qualified, techniques under development, and cites examples of inspection performed on waterborne ships.