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Inspection of North Sea oil platform: 25 years of equipment development

As with any metal structure, fatigue and corrosion of oil platforms are major concerns that require constant surveillance. Visual inspections can be carried out underwater effectively by divers, but more sophisticated nondestructive test (NDT) methods are sometimes necessary. This paper will trace the development of equipment from simple encapsulated versions of land-used instruments where the main question was whether to train NDT operators as divers or vice versa, to the modern systems operated from remote operated vehicles. Some of the interesting innovations along the way, such as torch-like ultrasonic thickness gauges, and devices for detecting flooded members will be described.