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Weak Rivets May Have Sped Sinking of Titanic
Pickens writes "Metallurgists studying the hulk of the Titanic argue that the liner went down fast after hitting an iceberg because the ship's builder used substandard rivets that popped their heads and let tons of icy seawater rush in. They say that better rivets would have probably kept the Titanic afloat long enough for rescuers to have arrived, saving hundreds of lives. The team collected clues from 48 Titanic rivets and found many riddled with high concentrations of slag, a glassy residue of smelting that can make iron brittle. To test whether this extra slag weakened the rivets, scientists commissioned a blacksmith to make rivets to the same specifications as those used to join steel plates in the hull of the Titanic. When the plates were bent in the laboratory, the rivet heads popped off at loads of about 4,000 kg. With the right slag content they should have held up to about 9,000 kg. Even a few failures because of flawed metal would have been sufficient to unzip entire seams, because as faulty rivets popped, more stress would have been placed on the good ones, causing them to break in turn. The shipbuilder, which is still in existence, denies it all."
Why do people find the Titanic so fascinating? I still see documentaries come up every now and then. There were worse tragedies and boat disasters than the Titanic. Is it because it was a ship mainly for the rich that they said was unsinkable but did? For all the Titanic buffs, build a bridge and get over it... or will that have cracks too? Oh the humanity.
Analytic & algebraic topology of locally Euclidean meterization of infinitely differentiable Riemmanian manifold
The Titanic has two sister ships the Olympic (built before) was known as "Old Reliable" retired and dismantled after sailing for 24 years, and the Britannic (built after, sunk by a mine)
If the rivets were such inferior quality why did the Olympic sail without problems (including being rammed by the cruiser HMS Hawke) for 24 years?
Puteulanus fenestra mortis
Ship building in early and mid WW2 was a race to make ships faster than the U-boats could sink them. Keep trading quality for quantity until the number that sink on their own approaches the number that the enemy sinks for you, and you have hit the right tradeoff.
I wonder how many of those ships made in the early supply of Britain survived more than a couple crossings before soaking up a torpedo? Need to find some statistics on how many ships simply sank due to defect vs attack.
I work for the Department of Redundancy Department.
The big thing here though is this "unzipping" thing I've seen quoted.
I'm interested if anyone knows about maritime riveting and can correct me because in aviation we not only use rivets of a standard design specification (predominantly) to reduce dissimilar metal corrosion but also they are riveted in set patterns that mean should one rivet fail then the resulting weakness and is to a greater degree minimised by the placement of other rivets. For example the most simple battle damage repair would be two sheets overlapping with a double row of staggered rivets at set distances (I forget the exact inches) - and that's a patch repair!
Unzipping, to me, implies that the metal was riveted in straight lines which would seem like an engineering faux pas of the highest order.
A thistle is a fat salad for an ass's mouth...
Jen McCarty was my labmate in grad school (we had the same adviser), so I heard about the Titanic rivets a lot.
Jen didn't know if all of the rivets were made of poorer-quality iron. She only had 48 to test (they're expensive to retrieve). I have no idea how those rivets were distributed about the ship. A statistician might be able to tell you how confident you can be with 48 sample out of population of hundreds of thousands. However, IIRC every single rivet tested was of the poorer quality.
I believe the rivets were pulled out of the Titanic itself. Even if they were gathered from the ocean floor around the wreck, I think it's highly unlikely that someone happened to dump bad rivets from the early 1900s in the middle of the North Atlantic right where the Titanic sunk.
Both Jen's grad-school research and TFA mention higher quality iron being used in ship rivets normally. While it was more difficult to test for slag in rivets 100 years ago, they were very good at knowing how to make better (read: stronger) iron, because ultimately you can just test the iron to failure and see how strong it was. Jen looked at iron from other structures built around the same time as the Titanic and they were definitely of a higher quality (I think TFA mentioned the Brooklyn Bridge).
Finally, slag doesn't grow in iron because they sit on the ocean for 100 years. These rivets are roughly an inch in diameter, and Jen cut them in half and looked inside them. There was corrosion on the outside, sure, but the impurities that are at issue here are embedded in the rivets. IIRC, slag is almost a glassy substance. It has different mechanical properties than iron, leading to stress concentrations in the iron surrounding chunks of it. These stress concentrations result in the iron failing under less overall stress than it would have otherwise.
Cover your butt. Bernard is watching.