A Ultrasonic Thickness (UT) Shots Inspection is a specialized non-destructive testing (NDT) process used to measure the thickness of steel plating and detect areas of corrosion, wastage, or structural thinning on metal-hulled vessels. This inspection is essential for maintaining vessel safety, confirming structural integrity, and meeting insurance or regulatory requirements.
UT inspections are particularly important for steel or aluminum vessels, where internal corrosion or hidden deterioration may not be visible during a standard visual survey. The goal of a UT inspection is to obtain accurate, measurable data on the remaining plate thickness of the hull, decks, tanks, or structural members. These readings help determine whether the vessel remains within safe operational limits or if repairs, plating, or replacement are required.
During a UT Shots Inspection, the Marine Surveyor uses a calibrated ultrasonic thickness gauge to take multiple readings across key areas of the hull and structure. The process typically includes:
- Preparation and cleaning of test areas to ensure accurate reading
- Systematic measurement of hull plating, keel, bilge, tank tops, and other structural members
- Identification of localized corrosion, pitting, or steel wastage
- Recording of all thickness readings and corresponding locations
- Optional grid mapping of readings for comprehensive documentation
- Inclusion of results within a formal survey report (if requested)
- Technical Note: All measurements are recorded in millimeters or mils and can be plotted on a hull diagram or plate map to clearly indicate areas of concern. This provides a visual representation of thickness variation, helping owners, buyers, and insurance underwriters assess vessel condition quickly and accurately. All measurements are non-destructive and performed from the accessible side of the plating, without the need for cutting or drilling.