Why She Sank In Only 18 Minutes

  • Thread starter Melissa E. Kalson
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Melissa E. Kalson

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How is it that Lusitania sank in only 18 minutes when it took Titanic 2 1/2 hours to sink? I know that they were rival shipping lines but were ships basically built the same way? And if so why the shortened sinking time? I've wondered about this for some time. Any opinions? Sincerely, Melissa K.
 
Dec 2, 2000
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Well, torpedoes aren't exactly subtle. Put one in the side of a ship and the BANG tends to leave a rather large hole which allows a lot of water to get into the ship in a very short amount of time. The explosion would tend to do a number on things like watertight bulkheads and doors if they happen to be too close. Also, if the WT doors were not closed when they needed to be this wouldn't help much.

Beyond that, your guess is as good as mine.

If you do some close checking, you'll find that the Lusitania and Mauratania were very different in some crucial respects from other commercial vessels in that they were built to suit Admiralty requirements for auxilary cruisers. As such, the watertight subdivision was more extensive then what one finds in general merchent practice.

Still the best subdivision in the world is worthless if you don't use it right or don't use it at all. While I can't prove it, I suspect that this was a much more important factor then we'll ever know.
 

Scott Reigel

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Jul 26, 2002
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I had read somewhere that it was possible that due to the differences in watertight subdivision and the placement of coal bunkers, Lusitania could have survived the damage that doomed Titanic, while Titanic could have survived Lusitania's torpedo hit. This of course assumes that all the WT doors are working as designed.

Any thoughts as to whether or not this is the case?

--SDR
 
Apr 27, 2001
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I think the main reason she went down so fast is the powerful second explosion, which probably ripped a hole in the side far larger than anything her compartments could contain. What caused that explosion? The jury's out on that one.
 

Matthew Lips

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Mar 8, 2001
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Right on, Shane, and like so many other juries it will probably have to stay out forever. Just like the Californian jury!
 
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Brent Holt

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I never have understood why the Lucy sank with a single torpedo hit. The watertight subdivison of the ship was extensive, basically built to a navy design. The compartments should have easily contained the explosion.
A secondary explosion would have to have been immense to cause enough damage to sink her. Although problems with the watertight doors, as with Britannic, could render the subdivision uselsss.
Brent
 
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Tom Pappas

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I have a theory about a possible cause of the secondary explosion. I think it was coal dust, but with a twist.

Those who deny the coal dust theory point out that there wouldn't have been enough of it to cause the kind of explosion that ripped out her side. But it seems to me that when a bunker even partially full of coal is hit by a metric ton of High Explosive, a huge amount of coal dust is produced instantly by the pressure wave from the exploding ordnance. Even her Admiralty-spec compartmenting[sup]1[/sup] wouldn't have prevented many spaces from filling with dust. Once it finds its way into a boiler room, a source of ignition is assured.

It is also worth mentioning, in the context of why she sank so rapidly, the fact that the effictiveness of watertight bulkheads is severely compromised once the ship has listed to the point where the water can flow around them! I think this fact must have hastened the demise of H.M.H.S. Britannic also.

[sup]1[/sup] H.M.S. Hood was subdivided similarly, and sank almost instantly. So Admiralty-spec compartmenting carries no guarantees.
 

Remco Hillen

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Jan 6, 2001
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Hello Tom,

I don't really understand what you mean by: "the fact that the effictiveness of watertight bulkheads is severely compromised once the ship has listed to the point where the water can flow around them!"
Could you explain this a bit further?

Regards,
Remco
 
Jan 5, 2001
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Hi Remco,

I guess Tom means that with open ports, or whatever, water can flow in through those; therefore getting behind one of the watertight bulkheads that was otherwise keeping the damage isolated by containing flooding forward of it.

(Sorry for pushing in and then confusing people!)

Best,

Mark.
 
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Tom Pappas

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Once the top edge of a w/t bulkhead slants below the waterline (which is what happens when the list becomes sufficiently severe), the bulkhead might as well not be there, because the water in the compartment flows past it.

Draw a square on a piece of paper. Draw a "waterline" horizontally across it about halfway up from the bottom. This is the "face-on" view of the bulkhead with the ship upright. Now rotate the paper (simulating a listing condition), redrawing the waterline as required to make it remain horizontal. At some point, the waterline will begin to intersect the top edge of the bulkhead. This is your leak.
 
Dec 2, 2000
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>>H.M.S. Hood was subdivided similarly, and sank almost instantly. So Admiralty-spec compartmenting carries no guarantees.<<

Especially when the shell penetrates inadaquate armour and explodes in the magazine.
lame.gif


>>Those who deny the coal dust theory point out that there wouldn't have been enough of it to cause the kind of explosion that ripped out her side. <<

Uhhhhh...not exactly. What they point to is the difference in outside water temperature as opposed to the temperature inside the ship which makes conditions ripe for condensate to form and wet the coal dust down. Kind of hard for the dust to explode when it's a wet mass clinging to the decks and bulkheads.

Just thought you'd like to know.
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Dec 2, 2000
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Good points in that post. The ammunition theory didn't hold water (Pardon the pun) under close examination for a lot of the reasons you cited. I would also add that where the ammunition was stored wasn't all that close to where the torpedo barged in.

I'm not so sure about coal being pulverized first then igniting. While I'm not up on the specifics, I'm aware of the fact that coal dust needs some very specific conditions in order to explode in regards humidity, oxygen, concentration of the dust, and an ignition source. It's something I learned about growing up in Pennsylvania. The coal fields were just a loud shout away from home and accidents like this were not as rare as the coal miners wished they were.

On the boilers...can't say as I know one way or the other. The problem is that I can't find any examples of a scotch marine boiler exploding under these conditions. If you know of any examples documanted on the net, could you dig up the links? It's been something I've been wondering about for several years now.

Having said that much, I wouldn't be surprised if one was ruptured by the blast from the torpedo, and if you have that much steam pressure released in an instant....well...it'll do more then crack a few coffee cups.
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Rumour has it it's tough on the firemen too.
 
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Nathan Good

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I believe the explosion that sank the Hood ripped the ship in two. I dont know of many ships that could float with both ends nearly fully open to the sea. Perhaps, similar to what Mr. Standart was saying, things on the Lusitania were happening so fast that proper procedures were not followed. I have a question: would it have been possible that the explosion destroyed certain WTD mechanisms deeming them unusable? Also, a hole potentially many decks high would allow an enormous amount of water to pour in, so fast that little could be done. That and the fact the ship was travelling at speed, I'm assuming would have a great impact on the speed of the sinking. This theory about the list having something to do with the sinking is interesting. I wonder if serious listing was considered during the designing pre-1906? Surely a torpedo hit would not have been?

Bye for Now,

Nathan

Also, is it assumed that the explosion, first or second, ripped apart a great amount of plating and that led to the sinking? Or is it that it ripped apart inner bulkheads? Maybe both.

Thank
 
Dec 2, 2000
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>>I have a question: would it have been possible that the explosion destroyed certain WTD mechanisms deeming them unusable? <<

Yes...in fact, I seem to recall that was one of the problems on the Britannic as well. A watertight door doesn't do you a lot of good if the frame it's in is distorted enough that the beast won't close. Explosions tend to do things like that.
 

Remco Hillen

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Jan 6, 2001
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Hello Tom,

Once the top edge of a w/t bulkhead slants below the waterline (which is what happens when the list becomes sufficiently severe), the bulkhead might as well not be there, because the water in the compartment flows past it.

Draw a square on a piece of paper. Draw a "waterline" horizontally across it about halfway up from the bottom. This is the "face-on" view of the bulkhead with the ship upright. Now rotate the paper (simulating a listing condition), redrawing the waterline as required to make it remain horizontal. At some point, the waterline will begin to intersect the top edge of the bulkhead. This is your leak


Ah ok, thanks for explaining that.
But I don't think this would have had much effect on the sinking rate of Britannic.
In Britannic's case, the forward 6 compartements were open to the sea; so water reached the WTD bulkhead between boilerrooms #4 and #5.
This bulkhead reached up to B-deck.
If water would go around this bulkhead like you describe, Britannic would have already been in her final minutes.

Regards,
Remco
 
Jan 5, 2001
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Hi!

I have to agree with you Remco. What I'm wondering Tom is whether or not you were referring to ports; in the light of what Remco says, Britannic would already have been doomed.

You might find these of interest:

Best regards,

Mark.
 
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Tom Pappas

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If the question is: would Lusitania have sunk if all her portholes and hatches were closed? Indubitably.

Whatever ones were open merely hastened the inevitable.
 
Jan 5, 2001
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Hi,

No, my question related to your original posting. Were you referring to ports as well as the watertight bulkheads if the ship were listing? And were you applying that to Britannic, which seems improbable?

Best regards,

Mark.
 

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