In Situ Corrosion Measurements and Management of Shipwreck Sites

Abstract

The overall impression of an iron shipwreck site is often dominated by the remains of the boiler, engine, and frames that once gave the vessel its form. In warm tropical to subtropical seawater, corroding iron and steel rapidly become encapsulated by encrusting organisms such as coralline algae and bryozoa (North, 1976). This encapsulation begins the process of separating the anodic and cathodic sites of the corrosion cell, with oxygen reduction generally happening on the outer surface and oxidation of the metal occurring underneath the marine growth (MacLeod, 1989a). Under such conditions, the cathodic reduction of dissolved oxygen is the rate-determining step in the overall corrosion process.