RMS Titanic

RMS Titanic (also SS Titanic) was the second of a trio of superliners intended to dominate the transatlantic travel business.{{ref|trio_ref}} Owned by the White Star Line and built at the Harland and Wolff shipyard in Belfast, Ireland, the Titanic was the largest passenger steamship in the world at the time of its launching. During Titanic's maiden voyage, it struck an iceberg at 11:40 PM (ship's time) on Sunday evening April 14, 1912, and sank two hours and forty minutes later at 2:20 AM Monday morning.

The rediscovery of Titanic

The idea of finding the wreck of Titanic, and even raising the ship from the ocean floor, had been around since shortly after the ship sank. No attempts were successful until September 1, 1985, when a joint American-French expedition, led by Jean-Louis Michel and Dr. Robert Ballard of the Woods Hole Oceanographic Institution, located the wreck. It was found at a depth of 2 miles (3,800 m), south-east of Newfoundland at {{coor dms|41|43|55|N|49|56|45|W|}}, 13 miles (22 km) from where Titanic was originally thought to rest.

Related Topics:
Wreck - September 1 - 1985 - Robert Ballard - Woods Hole Oceanographic Institution - Newfoundland

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The most notable discovery the team made was that the ship had split apart, the stern section lying 1,970 feet (600 m) from the bow section and facing opposite directions. There had been conflicting witness accounts of whether the ship broke apart or not, and both the American and British inquires found that the ship sank intact. Up until the discovery of the wreck, it was generally assumed the ship did not break apart.

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The bow section had embedded itself 60 feet (18 m) into the silt on the ocean floor. Besides parts of the hull having buckled, the bow was mostly intact, as the water inside had equalised with the increasing water pressure. The stern section was in much worse condition. As the stern section sank, water pushed out the air inside tearing apart the hull and decks. The speed at which the stern hit the ocean floor caused even more damage. Surrounding the wreck is a large debris field with pieces of the ship, furniture, dinnerware and personal items scattered over one square mile (2.6 km²). Softer materials, like wood and carpet, were devoured by undersea organisms. Human remains suffered a similar fate.

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Originally, historians thought the iceberg had cut a gash into Titanic's hull. Since the part of the ship the iceberg damaged was buried, scientists used sonar to examine the area and discovered the iceberg had caused the hull to buckle, allowing water to enter Titanic between its steel plates. During subsequent dives, scientists retrieved small pieces of Titanic's hull. A detailed analysis of the pieces revealed the ship's steel plating was of a variety that loses its elasticity and becomes brittle in cold or icy water, leaving it vulnerable to dent-induced ruptures. Furthermore, the rivets holding the hull together were much more fragile than once thought. It is unknown if stronger steel or rivets could have saved the ship.

Related Topics:
Sonar - Brittle

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The samples of steel rescued from the wrecked hull were found to have very high content of phosphorus and sulphur (four times and two times as high as common for modern steels), with a manganese-sulphur ratio of 6.8:1 (compare with over 200:1 ratio for modern steels). High content of phosphorus initiates fractures, sulphur forms grains of iron sulphide that facilitate propagation of cracks, and lack of manganese makes the steel less ductile. The recovered samples were found to be undergoing ductile-brittle transition in temperatures of 32 °C (for longitudinal samples) and 56 °C (for transversal samples—compare with transition temperature of −27 °C common for modern steels—modern steel would become as brittle between −60 and −70 °C). The anisotropy was likely caused by hot rolling influencing the orientation of the sulphide stringer inclusions. The steel was probably produced in the acid-lined, open-hearth furnaces in Glasgow, which would explain the high content of phosphorus and sulphur, even for the times.{{ref|Titanicsteel}}

Related Topics:
Phosphorus - Sulphur - Manganese - Ductile-brittle transition - Anisotropy - Hot rolling - Stringer - Glasgow

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Dr. Ballard and his team did not bring up any artefacts from the site, considering it to be tantamount to grave robbing. Under international maritime law, however, the recovery of artefacts is necessary to establish salvage rights to a shipwreck. In the years after the find, Titanic has been the object of a number of court cases concerning ownership of artefacts and the wreck site itself. In 1994 RMS Titanic, Inc. was awarded ownership and salvaging rights of the wreck.

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Approximately 6,000 artefacts have been removed from the wreck. Many of these were put on display at the National Maritime Museum in Greenwich, England, and later as part of a travelling museum exhibit.

Related Topics:
National Maritime Museum - Greenwich - England

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