"Dry Dock" Damage


Karim

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May 22, 2016
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Hello all,

I am not trying to imply that Titanic received damage while in dry dock; my idea is that while Titanic was lifted by the berg during contact, it must have bent and distorted the hull in a similar fashion to an improperly "hoisted" (don't know the term) ship in dry dock.

Has anyone studied this as a possibility of damage during contact, and if so, what effect did it have on the flooding and sinking?
 
Dec 4, 2000
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Karim --

The idea of "dry dock damage" is a central point in my book "Titanic Myths, Titanic Truths." I've discussed in various threads on this forum. Yes, I do think the hull was damaged by being lifted on the starboard side while sliding over the iceberg. Good to welcome someone else thinking along these lines.

-- David G. Brown
 

Karim

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May 22, 2016
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David, thank you for your reply.

I've read your hard-a-starboard paper on ET and I have to say it was one of the most interesting reads yet. I highly admire your work and will purchase your book as soon as possible.

Do you think the majority of the damage incurred was due to this effect? Or was it a minor player in the intake?

P.s; I read a reply of yours on ET where you state that the engineers of Titanic were most probably keeping the ship on an even keel during the sinking. Would you mind elaborating on that? Maybe also mention how you came to this conclusion?
 

Jim Currie

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Apr 16, 2008
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Funchal. Madeira
Karim --

"Yes, I do think the hull was damaged by being lifted on the starboard side while sliding over the iceberg."

-- David G. Brown


David,

I think I have pointed this out to you before, but in case I didn't or you have forgotten about it, here it is again.

When a vessel is floating.. moving or stopped in a stable condition, her Center of Gravity is below her Metacenter. If she inclines left or right, she will return to the upright condition... slowly or quickly. As in dry-dock or when the bottom of a vessel contact a solid or even floating object, her center of Gravity is momentarily displaced upward above her Metacenter. This produces an overturning moment and the vessel will lurch suddenly left or right. The same thing happens when a deck cargo of timber absorbs water and hence weight above the Center of Gravity. I have actually been in a situation similar to what you suggest for Titanic. The result was briefly terrifying, I can assure you. Most recently, the same thing happened to The Costa Concordia. If you doubt what I say, I suggest you check with a good Ship Stability publication.

If, you are correct, and Titanic did temporarily ground...and a form of grounding is what we are discussing... then the ship would have lurched over very suddenly to one side. Chairs, items on desks and tables would have caused the most incredible racket as they slid off and landed on the deck. People all over the ship would have become instantly aware and if sleeping...awake. I can assure you, once experienced, this phenomenon is never forgotten.

Look at it another way. If a vessel's weight is even temporarily borne by a very large floating object, part of her originally buoyancy will be transferred to the object and the vessel in question becomes unstable. Anyone who has ever been present when a submersible heavy lift ship is operating will bear this out. I have loaded barges and even ships onto such craft. It's a very delicate operation.

Jim C.
 

Karim

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May 22, 2016
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Jim, thank you for your reply.

I think you've misunderstood what we meant by lifted. I agree completely with what you've said, but the grounding of the Costa Concordia is not the same as what's being described here. The Concordia grounded over a larger portion of the ship's length and suffered far graver damage from the grounding than Titanic. Basically, an underwater shelf that is as "high"as the "pegs" used to keep a ship hoisted in dry dock would have been sufficient to cause damage, and that is what we are discussing here; not severe lifting (feel free to correct me David).

Wouldn't the classical sideswipe theory cause the Titanic to lurch over as well anyways? I believe it would.
 
Dec 4, 2000
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I agree with both of the above posts. A large "lifting" as Jim describes would have tossed things about. But, that's not what the men who experienced it described. The key witnesses here are lookouts Fleet and Lee. They talked of a slight lifting of the starboard side as the berg passed. They were perhaps 110 feet above the keel. For a sailor to describe a slight lifting means the crow's nest did not lean over to the port side to an appreciable amount. My experience in schooners taught me that a tilt (heel to sailors) of the deck is not much noticed below 4 degrees, but becomes a factor in moving about at near 10 degrees. Using these guidlines, I looked at a lifting the starboard side 4 feet. That would have produced a heel of roughly 2.5 degrees on deck -- barely noticeable to most people. At the crow's nest, however, the movemnt would have been a swing of 4 feet to port which would have been noticed by the lookouts without causing any alarm about the ship's stability.

Of course, like everyone else I have no factual knowledge of how much lifting or heeling took place. That doesn't change anything because the amount of lift was not enough to move the CG outboard of the CB. Titanic's natural righting arm of G-Z kept the boat from rolling over and returned it to full upright once the ship and berg parted company.

.. David G. Brown
 

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