It wasn’t a single factor that sent Titanic to the bottom of the ocean, it was a chain of them.
One hundred years ago, the ship that had been called ‘virtually unsinkable’ struck an iceberg and sank within three hours, taking many of her passengers and crew with her. History is clear enough on this point, but a mystery follows- how did the Titanic strike the iceberg in the first place?
Another question is how did the ship sink so quickly? The water-tight containers meant that the Titanic should have acted as her own lifeboat, floating until help arrived.
Some of the answers, according to scientists, lie in the physics of her construction, the climatic conditions thousands of kilometres away and the iceberg itself.
Science writer Richard Corfield believes the placing of the rivets may have contributed to the disaster. In an article published in Physics World, he highlights the findings of metallurgists Tim Foecke and Jennifer Hooper McCarty, who suggest the rivets that held the ship’s hull together were not uniform in composition or quality and not been inserted in a uniform fashion.
This may have been the result of a cost-cutting exercise and meant that the part of the hull that hit the iceberg was substantially weaker than the main body of the ship.
The rivets at the bow and the stern were not hydraulically inserted, so they would have been as firmly installed as those in the middle three-fifths of the ship, according to Corfield. “Since the impact was at the starboard bow and the impact was near a seam of rivets, the rivets, rather than the placing of them, contributed to the sinking of the Titanic.”
Climatic conditions also played an important role, as the Caribbean and the Gulf of Mexico were experiencing an unusually hot summer thousands of kilometres away. This would have created a more intense Gulf Stream, according to Corfield.
This intensified the boundary between the Labrador Current and the Gulf Stream near Newfoundland, creating a barrier of icebergs along the interface. The iceberg that sank the Titanic was located right at the intersection of the Gulf Stream and the Labrador Current.
“Another way of saying this is that there were more icebergs in a smaller area than usual,” Corfield says. “The Titanic steamed at almost full speed directly into this ‘minefield of ice’.”
The icy Labrador current may have also played a further role in the disaster, according to British historian Tim Maltin. The air column was cooling from the bottom up, creating layers of cold air below layers of warmer air.
This phenomenon, known as thermal inversion, causes light to refract in unusual ways, making objects appear higher (and nearer) than they actually are, on a false horizon. The mirage between the false horizon and the real one prevented the lookout from seeing the iceberg until it was only a mile away.
The distorted air also disrupted the Morse lamp signals between the Titanic and the nearby Californian, so neither ship could see the other’s signals. The distress rockets fired by the Titanic to appear lower relative to the ship, so the Californian believed that she was sailing away.
The final breakup
In 2000 David Concannon spotted some ‘ribbons of steel’ some distance from the main debris field. This suggested that, instead of just causing gashes to the Titanic’s side, the iceberg may have ripped open the bottom of the hull.
Another expedition in 2005 revealed these to be a large portion of the hull, which had been torn away from the ship as it sank. The dive team also observed that the compression to the ship appeared to have occurred at the top of the hull, rather than the bottom, indicating that it sank at a much shallower angle than previously believed.
The final breakup would have come as a surprise — the shallower angle would have led the passengers and the crew to assume it would float for a few hours more.