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Diego Uriol
Member
Username: deigus13
Post Number: 22
Registered: 10-2006
| | Posted on Saturday, November 4, 2006 - 4:24 am: | 
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I've noticed in Cameron's Titanic that, for example, the water level outside the ship was in some place, and inside water was filling a deck under! |
Michael H. Standart
Moderator
Username: mstandart
Post Number: 11096
Registered: 12-2000
| | Posted on Saturday, November 4, 2006 - 6:33 am: |
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Yeeeeeesssssss....not really hard to understand either. The weight of the water is going to tend to pull the bow under, but it'll be a spell of time before it rises high enough inside to come level with the sea outside.
Cordially,
Michael H. Standart
Equal Opportunity Curmudgeon
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Diego Uriol
Member
Username: deigus13
Post Number: 23
Registered: 10-2006
| | Posted on Saturday, November 4, 2006 - 2:23 pm: |
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Thank you Michael!
Diego |
Ryan McKeefery
Member
Username: ryan_mckeefery
Post Number: 679
Registered: 8-2005
| | Posted on Saturday, November 4, 2006 - 5:56 pm: |
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You may have noticed, Diego, that a large portion of any ship (unless in dry dock or on a slipway) lies below the surface of the water - and everything inside this portion is dry as a bone.
When the hull is breached however, the amount of ship beneath the water increases, but the volume of air within always remains the same until every inch of the hulk is submerged, and the air inside is then consequently expelled.
I'd like to add that if a ship breaks at the surface, as in the case of Titanic, the volume of air within the remaining hulk is somewhat lesser.
Regards, Ryan.
The worlds leading authority in bathtub experiments.
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Samuel Halpern
Member
Username: cmdrsam
Post Number: 1395
Registered: 3-2003
| | Posted on Sunday, November 5, 2006 - 5:57 pm: |
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"When the hull is breached however, the amount of ship beneath the water increases, but the volume of air within always remains the same until every inch of the hulk is submerged, and the air inside is then consequently expelled."
Not quite. The so called watertight compartments were not airtight, and air would be expelled as fast as water flooded in.
There are no Unsinkable Theories.
Sam Halpern
40° 23' 50'' N, 74° 13' 55'' W.
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Ryan McKeefery
Member
Username: ryan_mckeefery
Post Number: 681
Registered: 8-2005
| | Posted on Sunday, November 5, 2006 - 6:26 pm: |
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I know. I mean the volume of air inside the submerged portion of the hull remains the same as it would be in normal conditions.
The worlds leading authority in bathtub experiments.
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Robert T. Paige
Member
Username: jnb
Post Number: 573
Registered: 5-2005
| | Posted on Monday, February 12, 2007 - 6:18 am: |
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Preface this with "Of course there wouldn't have been anyone alive who witnessed this."
Would the scenes in "Titanic (1997)" of doors being blown off as the water rushes down the corridors have been in the stern section rather than the forward section ? For example, Ken Marschall's paintings show the stern section more or less devastated while the forward section was more or less intact. I have read that the stern section sank much more rapidly than the forward section and the air pressure caused by the water "wreaked havoc" (after the two parts separated.)
Also, could we assume that there will be nothing but piles of rust at the wreck site (at 12,500 ft. depth, that is )in the not too distant future and eventually that even these might be absorbed until eventually there were absolutely no traces left ? And there's really not much that could be done about it ?
For example, have any explorations been made to wreck sites of iron ships which have been on the bottom longer than Titanic ?
Respectfully,
Robert T. Paige
"The best I've seen, ma'am....Hardly any rats."
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Michael H. Standart
Moderator
Username: mstandart
Post Number: 11825
Registered: 12-2000
| | Posted on Monday, February 12, 2007 - 6:29 am: |
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That part about air pressure doing the damage to the stern is a bit dodgy in my opinion. Air compresses whereas water does not. I think that any implosions would have happened as a consequence of any sealed compartments such at the cold storage being crushed.
Keep in mind that once the midsection collapsed, there was already substantial damage to the stern. With it's structural integrity compromised, I don't think anything else that followed would have done it a lot of good. Especially the impact with the bottom.
On the question of explorations, the Andrea Doria might be instructive in her own fashion. She may not have been on the bottom as long, but that just means you get to see what happened when it's a bit fresher, and she has been explored from the inside. Come to think of it, so has the Britannic.
Cordially,
Michael H. Standart
Equal Opportunity Curmudgeon
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Bill West
Member
Username: bill_west
Post Number: 55
Registered: 12-2005
| | Posted on Monday, February 12, 2007 - 8:54 pm: |
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Blowing the doors is fairly easy, a 2.5’x6’ door exposed to one psi has a one ton load on it, the latch and hinges aren’t that strong, even the center panel would break out. One psi is a mere two feet of water all over. In a sinking the air would quickly compress, under two feet of water it has 1/15th the volume so you might as well just look at the water case. For the freezer Mike your point would continue because while blowing the door out only involves breaking the latch, inward involves a thick door becoming wedged in its frame. It might take 5-6’ of water to start a rip in one of the bulkheads.
What looks flashy in a film is that fact that the rushing water adds in lots of additional force from its momentum so it doesn’t even have to fill the corridor to the ceiling. Then as the doors fail the air pockets expand again for a moment and really throw the debris around. But a mere two feet below the ocean surface is enough to start it all so I think the movie sounds realistic for the case of the stern suddenly being opened and a new waterline engulfing the lower decks.
Bill |
Jeremy Aufderheide
Member
Username: jerauf
Post Number: 9
Registered: 1-2007
| | Posted on Monday, February 12, 2007 - 9:25 pm: |
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Regarding the devastation of the stern, wasn't there a theory a while back that the force of the stern sinking caused a downrush of water that caught up with it when it hit the bottom, thus causing further damage? |
Michael H. Standart
Moderator
Username: mstandart
Post Number: 11837
Registered: 12-2000
| | Posted on Tuesday, February 13, 2007 - 7:07 am: |
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>>wasn't there a theory...<<
If you're referring to downblast, this is the first time I've heard of it in relation to the Titanic's stern, though I've heard of it being mooted with the Bismarck. I don't know if there's anything substantive to it, but there might be.
Cordially,
Michael H. Standart
Equal Opportunity Curmudgeon
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Paul Rogers
Member
Username: progers
Post Number: 464
Registered: 11-2000
| | Posted on Tuesday, February 13, 2007 - 12:17 pm: |
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Jeremy,
The 'Downblast Theory' was, I believe, originally postulated by Charles Pellegrino and was discussed in this thread. If you use the Search function on the Message Board, and search for the words 'downblast' and 'stern', you'll find quite a few other relevant threads as well.
Hope this helps!
Addendum:
I should have pointed out that the thread linked to in my post related specifically to the downblast theory vs the bow. There are other threads (via Search) that relate to the same theory and the stern. |
