ROBOTIC INSPECTION OF CRUDE OIL CARRIER TANKS

THE INSPECTION OF VERY LARGE CRUDE CARRIERS (VLCC) FOR STRUCTURAL RELIABILITY IS AN IMPORTANT ENVIRONMENTAL CONCERN. THESE LARGE VESSELS TRANSPORT CRUDE OIL IN SUCH QUANTITIES THAT THE CONSEQUENCE OF AN OIL SPILL DUE TO A BROKEN WELD ARE VERY SERIOUS. IMPROVED TECHNIQUES ARE NEEDED TO INSPECT VLCC TANKS FOR DEFECTS SUCH AS CRACKS IN SEAMS, CORROSION AND FAILED STRUCTURAL MEMBERS. THE COST OF INSPECTION IS HIGH BECAUSE THE SHIP MUST BE TAKEN OUT OF SERVICE AND BROUGHT TO A REPAIR FACILITY. AMERICAN RESEARCH CORPORATION OF VIRGINIA PROPOSES TO REMEDY THIS SITUATION BYDEVELOPING A ROBOTIC SYSTEM INCORPORATING MAGNETIC EDDY CURRENT AND VIDEO CAMERA INSPECTION. SIGNALS DUE TO COLD WORKING OF METAL COMPONENTS WILL BE USED TO ASSESS THE DAMAGE STATE OF TANK MATERIALS. THE PROGRAM IS INNOVATIVE IN APPLYING SCANNING EDDY CURRENT AND SIGNAL ANALYSIS TECHNIQUES TO ACHIEVE THE PHASE I OBJECTIVE OF DEVELOPING ANEDDY CURRENT SCANNING SYSTEMS, FABRICATING WELDED SAMPLES, COLLECTION AND ANALYSIS OF DATA AND SPECIFICATION OF A REMOTE INSPECTION SYSTEM FOR TANK EVALUATION. PHASE I WILL CONSIST OF A PROOF-OF-PRINCIPAL DEMONSTRATION OF THE EDDY CURRENT INSPECTION AND SPECIFICATION OF THE ROBOTIC SYSTEM. THE PHASE II PROGRAM WILL INVOLVE DEMONSTRATION OF A PROTOTYPE SYSTEM ON A MOCK-UP OIL CARRIER TANK.