Global Fastener News

Did Weak Rivets Allow Titanic Hull to Unzip?

John Wolz

Editors Note: Articles in Media Spotlight are excerpts from publications or broadcasts that show the industry what the public is reading or hearing about fasteners and fastener companies.
Did “weak rivets” allow the Titanic hull to “unzip” when the famous ship struck an iceberg on April 15, 1912?

“The liner would have survived the collision for long enough for most of, or even all, its passengers to be rescued had it not been put together with weak rivets that caused its hull to ‘unzip’ on impact with the ice,” The Times of London reported.

Could a rescue ship, which arrived within two hours after the Titanic sank, have saved the 1,523 people who died?

“The most celebrated disaster in maritime history owed as much to substandard rivets as it did to the iceberg,” reporter Mark Henderson wrote.

In an article headlined “Tiny flaws that Caused a Titanic Waste of Life,” Henderson noted that “faulty construction has long been suspected as having contributed to the loss,” the “first experiment to mimic what happened to the rivets that held the hull together has shown that they could not have withstood the collision. This weakness meant that either five or six of the ship’s watertight compartments flooded, causing the ship to sink in slightly more than two hours. With stronger rivets, fewer compartments would have been compromised, and although Titanic would probably still have sunk it would have remained afloat for several hours longer.

Two metallurgists, Tim Foecke, of the US National Institute of Standards & Technology and Jennifer Hooper McCarty of Oregon Health & Science University, developed the rivet theory after examining 48 popped rivets from the wreck.
Foecke and McCarty found that the wrought iron contained 9% slag – a glass-like substance that adds strength at concentrations of 2% to 3% but weakens metal at higher levels.

Foecke commissioned UK blacksmith Chris Topp to produce rivets to the same specifications. The rivets were installed in steel plates and bent in the laboratory. The rivet heads popped off at loads of about 4,000kg (9,000lb). With the right slag content, they should have lasted until a load of about 9,000kg.

Even a few rivets failing could have led to the unzipping. As faulty rivets popped, “a domino effect ensued, distributing the increased loads to other rivets until the damaged seams began to open up,” Foecke told the Times. �2006 FastenerNews.com