Shell Plating

Outer steel envelope of the hull, divided into bottom plating, side shell, and sheer strake. Thickness, grade, and seam locations are fixed by class scantlings under the IACS Common Structural Rules — net thickness for tankers and bulkers since 2006, with a separate corrosion margin so the as-built plate satisfies strength after wastage. Higher-tensile steel (AH/DH/EH grades per IACS UR S6) is used in stress-critical zones such as deck strakes, bilge strakes and the sheer; mild steel elsewhere. Each strake is identified by a letter from the keel outboard so surveyors can reference UTM gauging points consistently between intermediate and renewal surveys.