What sank the RMS Titanic?
What sank the Titanic? It hit an iceberg of course. That is how Tim Foecke, staff materials scientist, National Institute of Standards and Technology, sums up some of the findings of a panel assembled to perform the first detailed scientific investigation of the wreck. He's only half kidding. It really did hit an iceberg but Foecke uses the line in a rebuttal of the "Brittle Steel" theory. That theory suggests that brittle hull steel allowed the ship to shatter on impact with the iceberg.
"The details of the metallurgy or the design are not going to remove the culpability of driving 24 miles an hour through an iceberg field after ignoring warnings," says Foecke. "What it may influence is the details of how fast she sank."
Foecke says the evidence suggests that a very unlucky set of circumstances involving collision dynamics, ship design and riveting may have led to the most famous maritime disaster in history. "The fracture toughness of the hull steel at those temperatures was adequate for the application," Foecke says. "It was state of the art at the time. There was no indication of brittleness in the steel. We have looked all over the debris field and on the wreck itself. We see a lot of twisting of steel."
At a seminar in room-1610 Engineering Hall, hosted by MS&E Professor Eric E. Hellstrom, Foecke passed around a one-inch-thick piece of the Titanic's hull which was bent more than 90 degrees over a five-inch span. Foecke says that the bending occurred in icewater as the ship settled to its resting place under 12,000 feet of water.
Foecke presented results on the structural and metallurgical analysis of Titanic, and results generated from the expedition mounted to the wreck in August of 1998. Under a scenario known as the "docking phenomenon" Foecke says the iceberg was able to sample the hull for weak rivets.
"Where you have two large bodies, 400,000 tons of ice and 46,000 tons of ship, they hit and bounce apart and suction brings them back together as they dock along side. The impact gets progressively lighter and longer in duration until in the end you're scraping until you finally part company," Foecke says. The panel's investigation into the quality of the rivets suggests that bad batches would likely have been installed in groups as they came off the production line. The only quality control for identifying bad rivets at the time involved hitting them with a hammer after they were placed. If one did not "ring true" they were replaced.
Foecke is the chief metallurgical investigator on the Marine Forensics Panel of the Society of Naval Architects and Marine Engineers. He is currently a Materials Scientist in the Metallurgy Division at NIST.