Shell plating is the watertight steel skin forming a ship’s outer hull surface — the actual barrier between the sea and the vessel’s interior, supported by the internal structural framework beneath it.
Types of Shell Plating by Location
- Bottom shell plating — the underwater hull surface, subject to the most structural loading and grounding risk
- Side shell plating — the vertical hull sides between the bottom and deck
- Sheer strake — the uppermost strake (row) of side shell plating, where it meets the deck, a particularly critical structural zone given the stress concentration at this junction
How Shell Plating Attaches to the Structure
Shell plating is welded to the frames, girders, and bulkheads that form the ship’s internal skeleton — it’s not a free-standing skin but an integrated structural element that itself contributes significantly to the hull’s overall strength, not merely a watertight covering.
Plate Thickness
Shell plating thickness varies by location and vessel size — areas subject to greater structural stress (bottom, sheer strake) are typically thicker than less-stressed areas, calculated according to classification society structural rules rather than a uniform thickness across the entire hull.
Corrosion and Inspection
Shell plating is subject to continuous corrosion exposure from seawater, making thickness measurement surveys (checking that plating hasn’t corroded below safe minimum thickness) a standard, mandatory part of periodic drydocking surveys.
Exam Relevance
Shell plating’s structural role, thickness variation by location, and inspection requirements are core Ship Construction topics in deck and engineering officer competency exams.