Since Titanic’s discovery there have been a total of seven expeditions to the wreck in manned submersibles. On some of those missions, groups of international scientists have accompanied the salvagers and photographers to study the ship’s structure, disintegration, and metals as well as her deep-ocean environment in hopes of solving some of Titanic’s enduring mysteries. They’ve made some startling discoveries.

At the time of Titanic’s sinking, it was widely held that she had suffered a 300-foot gash in her starboard side that opened her up to massive flooding. During testimony after the tragedy, naval architect Edward Wilding from Harland & Wolff, Titanic’s builders, speculated that a more likely scenario was that several of the ship’s 16 “watertight” compartments had suffered small but significant individual damage, which allowed water to fill them at different rates, thus keeping the ship afloat for two and a half hours.

Because much of Titanic’s bow section is buried in mud, Bob Ballard¹ and his team could not see where most iceberg damage would have been. They did, however, see some separations along steel hull plates where rivets had popped free, perhaps on impact with the ice.

⁴When the French submersible Nautile visited the wreck in 1996, she held acoustic² equipment that allowed scientists to “see through the mud” covering the bow. They saw six thin slits, some no wider than a finger, at different points along the hull. Naval architects, again from Harland & Wolff, had earlier used a computer model to learn what kind of flooding such openings below the waterline could have caused had they resulted from hitting the iceberg. They determined that pressure could have forced water into the hull at a rate of nearly seven tons a second, fast enough to sink the bow after about two hours.

Researchers have also been studying metal samples and rivets retrieved from the wreck. Some steel from that time was higher in sulfur and phosphorus than is common today, and it fractured easily in extremely cold temperatures. The temperature in the North Atlantic on Titanic’s fateful night was near freezing, cold enough to have made the metal brittle. In addition, a few of the ship’s wrought-iron rivets were found to have a high slag³ content as well as structural imperfections that may have caused them to unzip along hull seams. Finally, computer analysis shows that as the bow sank and the stern began to rise, the stress on the ship’s midsection was more than 50 percent greater than Titanic was designed to bear. This combination of stress, cold, and structural imperfections may have caused the ship to snap apart like shattering glass.

⁶Such technical analyses are enlightening. But it is the eyewitness accounts that most strongly convey the human tragedy of the ship’s final moments. Wrote survivor Jack Thayer: “We could see groups of the almost fifteen hundred people still aboard, clinging in clusters or bunches, like swarming bees; only to fall in masses, pairs or singly, as the great after part of the ship… rose into the sky…. Gradually she turned her deck away from us, as though to hide from our sight the awful spectacle.” The “long continuous wailing chant” of those left adrift in the icy sea eventually faded away.

What’s next for Titanic? Her salvage and the controversy surrounding it will continue. One company is seeking the right to lead sightseeing tours to the wreck. Iron- eating bacteria are devouring her hull. Yet one fact remains uncontested: Titanic continues to hold the hearts and minds of people around the world.