[BITList] titanic

[x50type at cox.net]

Hugh,

In the first part of my dissertation I may have adequately covered the binoculars and the locked/unlocked crow’s nest door. apparently key boards  [a wooden board with hooks there-in from which keys can be hung] were invented après Titanic.

Sailing too fast .... for what?
Sailing too fast in iceberg infested waters is clearly to be avoided – speed kills! But if the master is to keep on good terms with the owners [i.e. keep his job], he better not be late on arrival. The heedlessness of the captain who failed to slow down in a known field of icebergs was necessary if he was to remain as master.

"Poorly cast wrought iron rivets"? I didn't know wrought iron could be cast. There are wrought iron bridges still in good order.
Poorly cast wrought iron rivets  -- to be honest, I don’t know exactly how rivets are wrought or cast – but  researchers found that wrought-iron rivets made of bad iron with lots of slag inclusions pop their heads off much more easily than either steel rivets or wrought-iron rivets made with better material. Significantly, many of the steel plates recovered from the wreckage were missing their rivets altogether. And riveting is not a gracefully-degrading fastening method. Once one rivet in a row pops, the ones next to it get much higher stress and are likely to fail as well, leading to a kind of chain-reaction zipper effect. 

Rivets "inserted by hand". As opposed to what method?
According to a decade-long investigation, McCarty and Foecke, respectively graduate student at Johns Hopkins University and staff member at the Gaithersburg, Maryland office of the National Institute of Standards and Technology, obtained samples of the Titanic's hull, which consisted of large steel plates held together by rivets (electric-arc welding was not to become the standard steel-fabrication method until World War II). McCarty's archival research in England revealed that Harland & Wolff, the ship's Belfast builders, used two kinds of rivets: the more modern machine-formed steel rivets for the central part of the ship, and the old-fashioned hand-formed wrought-iron type for the stern and bow sections, where much of the collision impact probably occurred. 

The making and installing of wrought-iron rivets was largely a manual operation. The Titanic needed over three million rivets in all, and this huge demand led flocks of entrepreneurial iron makers to enter the field. The hand-stirred "puddling" process then used to make wrought iron from ore required strong and highly experienced workers, of which there were not enough in 1912. So it turned out that Harland & Wolff bought wrought iron from a wide variety of suppliers, some of whom were much less experienced than others. McCarty and Foecke have proof of this in the form of long, stringy slag inclusions they found in some of the recovered rivets. These inclusions tended to make wrought iron, an already a less satisfactory material than steel, even weaker.

Why weren't steel rivets used throughout? Besides reasons of cost, steel rivets had to be formed with hydraulic riveters—large U-shaped steel machines upwards of six feet high that had to be laboriously positioned on either side of the plate to be riveted. Then the rivet, shaped much like a blunt round-headed nail, would be heated, inserted into its hole through the two overlapping hull plates to be joined, and squeezed between the jaws of the riveter. This squeezing formed heads on both ends, and as the rivet cooled, the resulting shrinkage provided tension that held the two steel hull plates together in a watertight joint.

At least, that was how it was supposed to work. The problem was there was not enough room in the bow and stern areas to maneuver the hydraulic riveter. So the builders resorted in those areas to the older hand-forming way of riveting, which couldn't use steel rivets because of reasons to do with the different ways steel and iron cool. Wrought iron was more forgiving to the delays and variations involved when a boy tossed a red-hot rivet from a portable stove to the rivet gang, which placed it in its hole and pounded it in by hand. 

When the Titanic embarked on her maiden voyage on April 10, 1912, her bow hull plates were held together by wrought-iron rivets. The iron itself had probably never undergone any systematic quality testing, and the only quality tests done on the finished riveting job was a hurried hammer tap by an inspector, who listened to the sound it made. All this inspection could detect was loose rivets, not those made from defective wrought iron.

Have you ever come across or heard of a hydraulic riveting machine? Hugh  

I’m still researching the radio messages.

ct





From: HUGH 
Sent: Monday, April 02, 2012 10:29 AM
To: BitList 
Subject: Re: [BITList] ah- so now we know

Colin,

Sailing too fast .... for what?

No binoculars in crow's nest has been flogged to death - how do they know?

Radio message not passed on?  Source?

"Poorly cast wrought iron rivets"? I didn't know wrought iron could be cast.  There are wrought iron bridges still in good order.

Rivets "inserted by hand".  As opposed to what method?

If they must throw Titanic at us every five minutes, why don't they stick to the "human" angle based on real prople with nothing made up?  I managed to catch Episode 1 of Len Goodman's series on that theme, and I give him 11 out of 10.  It would have been 12 out of 10 had he not said she was launched by hydraulic jacks.

Hugh.


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