FACTS
by Subraj on Nov.22, 2009, under
A joint American and French expedition discovered the wreck of the Titanic in 1985, located about 150 km (about 95 mi) south of the Grand Banks of Newfoundland and about 3800 m (about 12,500 ft) beneath the surface of the North Atlantic Ocean. There have been seven expeditions to the site since then. But while these visits brought back haunting photographs and artifacts, none had ever been able to thoroughly assess the damage caused by the Titanic's collision with the iceberg. According to the 1996 expedition's experts, the bow portion of the Titanic struck the seabed at an angle and slid across it, plowing up sediments that covered the damaged area of the hull. To overcome this obstacle, the 1996 expedition used sophisticated sonar equipment, known as a sub-bottom profiler, to determine the extent and nature of the damage.
The Titanic was considered practically unsinkable because its hull was divided into 16 watertight compartments. The ship was designed to stay afloat with any two adjacent compartments or the front four compartments (which were smaller in volume) flooded. As a result, many authors of books on the disaster thought that only a huge tear, perhaps 90-m (300-ft) long, could have caused the 269-m (882-ft) long ship to sink. But Edward Wilding, a naval architect, testified in the wake of the disaster that the total area damaged by the iceberg was small, and probably did not exceed 1 sq m (about 12 sq ft). Others, however, did not believe that so large a ship could be undone by so little damage, and so the myth of the huge gash came into being.
Previous expeditions found no sign of a gash, however, and the latest sonar findings confirmed Wilding's belief that the damage was slight: six thin breaches spread out along a 35-m (110-ft) section of the hull with a total surface area of about 1 sq m (about 12 sq ft). The ruptures punctured 6 watertight compartments and were spread strategically along riveted seams. Had the damage been slightly less, the expedition's experts said, disaster might have been averted.
A 1991 expedition retrieved samples of the Titanic's steel for analysis. Tests determined that the steel's poor resistance to impact, a quality known as impact strength, combined with its chemical makeup, made the steel brittle. This problem was compounded by the fact that the Titanic was operating in unusually cold waters for that time of year. When exposed to near-freezing temperatures, tests showed that the steel became extremely brittle. The August 1996 expedition confirmed these findings and applied them to the question of whether or not the Titanic broke apart before sinking.
At the time of the Titanic's sinking there were conflicting reports as to whether the ship broke up at the surface or sank intact. All of the ship's surviving officers said the Titanic sank intact. A number of passengers, however, said that the ship broke up at the surface. Earlier expeditions established that the ship was in two pieces on the ocean floor, but some experts had postulated that the ship broke up on its way to the bottom. There was even a claim that there might be a third piece.
Based on the new findings about the nature of the damage sustained by the Titanic and the quality of the steel used in the hull, naval architects used a computer simulation of stresses in the hull, known as a finite element model, to determine the stresses that might have been prevalent during the sinking process. The simulation showed that the weight of the waterlogged bow would have generated enough stress to cause chaotic failures in the Titanic's steel plates as the ship sank, confirming reports that the ship broke apart before sinking. In addition, the 1996 expedition located a third piece of the ship, indicating that the ship broke in two places.
Great forces conspired to sink the Titanic, but scientists found that tiny ones will cause it to collapse and eventually disappear. In the 85 years since the Titanic sank, iron-eating microbes have slowly sapped the strength from the Titanic's structure. Eventually the wreck will no longer be able to support its own weight, the expedition's experts said.
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