An intelligent ultrasonic inspection system for flooded member detection in offshore structures

An ultrasonic system for automatic underwater inspection of steel jacket offshore installation is described. It is based on the unambiguous detection of water ingress in normally sealed tubular members, thereby providing an indication of through-wall structural failure. A novel transducer design, based on a dual frequency array of 1-3 connectivity thickness drive transducers, is used to provide the required sensitivity and act also as an environmental monitor for input to an expert system, which performs automatic data analysis. Although intended primarily for operation on a remotely operated vehicle, the system may be employed satisfactorily by a driver. A series of test trials is described, and the prototype is shown to perform very well for all intended modes of operation.