Technology / Materials Science

Yet another theory about why the "unsinkable" Titanic went down in 1912: The ship was a victim of rust, says Robert Baboian, the retired director of Texas Instruments' corrosion lab. The Titanic was held together by 3 million rivets made with a different type of iron than the hull plates, he notes. And once the hull was finished, the ship sat in seawater for a year while the inside was furnished. The dissimilar metals of the hull and rivets, bathed in electrically conductive seawater, might have created a circuit that slowly flecked away and weakened the rivets. One of the last photos taken before the ship's maiden voyage shows a pattern that suggests the rivets were rusting faster than the hull plates, says Baboian.

The Titanic's collision with the iceberg could have popped the weakened rivets, which would explain a clinking sound reported by survivors. The hull did not rip open, but a long opening just an inch wide between the hull plates could have sunk the ship. Video of the wreckage shows a narrow opening in the unburied part of the bow, Baboian says: "It is about at the level where the iceberg would have struck, and it is right where rivet popping could occur. I think that caused the Titanic to sink."