Weak Rivets May Have Sped Sinking of Titanic 296
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."
So it _was_ the rivets... (Score:3, Interesting)
Re:Wow... (Score:2, Interesting)
What is the fascination with the Titanic? (Score:4, Interesting)
Normalcy in the first half of 1900's (Score:2, Interesting)
Re:How is this new information? (Score:5, Interesting)
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?
Re:How is this new information? (Score:3, Interesting)
Perhaps the Titanic had one faulty batch of rivets which just happened to be in the wrong place. Perhaps the shipbuilders thought they could save a bit of money.
Re:Normalcy in the first half of 1900's (Score:5, Interesting)
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.
it would not have changed the casualty count (Score:3, Interesting)
Another hour or two on the surface would have just delayed the inevitable, but there was still nowhere else for the people to go.
Maritime riveting (Score:5, Interesting)
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.
Re:What is the fascination with the Titanic? (Score:2, Interesting)
MV Joola capsized near Gambia in 2002, with 2002, killing at least 1863 people.
And there there is MV Dona Paz. After a collision (and subsequent fire) in the Philippines in 1987 it sank, officially killing 1565 people (titanic was 1517), but the true number is likely way over 4000.
Of course those are forgotten as soon as the media has another "tragedy" to cover, and because no one is really surprised about it because of the major gaps in safety on those ships...
But as you say, the Titanic remain famous because of the prestige and attention she had prior to the accident...
Re:Denial (Score:5, Interesting)
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.
The might-have-beens (Score:3, Interesting)
The Olympic, five hundred miles off, make perhaps twenty-four knots in a pinch.
There were very few vessels that could match her speed. Carpathia, sixty miles off, could be pushed to fifteen - a nightmare four hour run through the arctic ice fields.
The North Atlantic is a mighty big ocean. Titanic had other problems.
The 24 hour radio watch was not standard. Titanic had a 500 KHz 5 KW Marconi spark-gap transmitter with a nominal range of 250 nm. She had far greater reach at night - but much would depend on the relative orientation of antennas and so on.
The best you could hope for in a receiver would be a very early vacuum tube design.
But operation burnt through your stock of tubes very quickly.
The Marconi Wireless Installation in R.M.S. Titanic [marconigraph.com]
Titanic's watertight compartments did not reach full height, as one flooded over, the next would begin to fill.
She was going down by the head, not on the level, which meant that evacuation was going to become progressively more difficult and dangerous.
It was a sloppy business from the start.
Titanic's crew poorly trained - if trained at all - in the use of her new and more efficient davits.