Corrosion of the Titanic
Dr Khalil Khan
24 September 2019
The Titanic was a luxury British steamship that sank in the early hours of April 15, 1912 after striking an iceberg, leading to significant loss of life. For decades, several expeditions sought to find the Titanic without success, a problem compounded by the North Atlantic’s unpredictable weather, the enormous depth at which the sunken ship lies, and conflicting accounts of the ship’s final moments.
Finally, 73 years after it sank, the final resting place of the Titanic was located by Robert Ballard, along with French scientist Jean-Louis Michel, on September 1, 1985. The Titanic had come to rest roughly 380 miles (612 kilometres) southeast of Newfoundland in international waters. The wreck of the Titanic lies at a depth of about 2.4 miles (3.8 kilometres).
After so long being submerged on the sea floor it is not surprising that the Titanic is corroding but there are some very interesting corrosion processes being discovered. The structure, chemistry and mineralogy of the corrosion products are allowing scientists to gain insight into the geochemistry of iron and other metals that were accidentally introduced into this deep-sea environment.
The most obvious corrosion products on the Titanic are rusticles. They resemble stalactites and form impressive structures. The rusticles have a smooth red outer surface made up of iron oxyhydroxide. When a rusticle is broken open the core is a bright orange colour. The needle-like crystals that make up the core are called 'goethite' [FeO(OH)]. When a biological activity test was performed it was shown that the rusticles grew in the presence of bacteria. The bacteria are a sulphate-reducing species that grow rapidly under anaerobic (low oxygen) conditions. This type of corrosion mechanism has all to do with microbial induced corrosion phenomenon.
New images of the Titanic reveal how the massive ship is being consumed by the ocean microbes.
The exploration team conducted five dives to the wreck recently using depth submergence vehicles and filmed the Titanic in 4K resolution for the first time, however, as nature takes its toll it may be one of the last times that exploration will be possible at the wreck site.
Project METaL’s short, accredited corrosion course will provide the details of this mechanism and together with other types of corrosion that are contributing to the deterioration of the Titanic’s structure.