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otnmbrd
 
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rhys wrote:


You're right: I wasn't factoring in the nature of the cargo. I wonder
if the viscosity of the oil (and its tendency to slosh in tanks) would
also affect stability in this scenario.


Tankers tend to have the majority of tanks divided into three separate
tanks (i.e., 1P, 1C, 1S) and when loaded, the ullage will be very close
to the top of the tank, so that any sloshing almost immediately pockets.
Without going into a long discussion, this fact coupled with the large
amount of stability, tends to negate the affects on stability.

I seem to recall the phrase "surface effect" or some such factor
relating to liquid cargo causing ships to capsize unexpectedly, or at
least before it was theoretically anticipated.


"Free surface effect". It's what caused the car carrier which recently
sank after a collision, to roll over so quickly. Again, not normally a
problem with tankers, unless they have double bottoms which are open
port to stbd.

otn