"Brian Whatcott" wrote in message
...
On Thu, 17 Feb 2005 00:13:16 -0500, rhys wrote:

On Wed, 16 Feb 2005 01:40:22 GMT, Brian Whatcott
wrote:

Warm water is less dense than cold water. Water expands more with
temperature than the metals, so a ship sits lower in hot water.
Moreover, water's rate of expansion increases as the temperature
rises. Another factor: water like oil, gets considerably less
viscous when warm, so a hull might be expected to be livelier, and
maybe the swell higher....

So the worst case scenario for a loaded ship would be a laden tanker
enduring a Red Sea or a Persian Gulf cyclone? I vaguely remember that
those areas are the hottest oceanic bodies on Earth.

By contrast, on a calm day in zero C. Antarctic water (ice-free,
however), the same laden ship would ride high(er) and dry.

Interesting!

R.

You actually contributed another gotcha: a crude oil cargo runs thin
and expands, so the CofG would go up a little higher while the
freeboard goes down, in the Gulf.

Brian Whatcott ALTUS ok


G Not all crudes are "thin", and many cool down after loading, but these
amounts (change in ullage) tend to be very small. Couple this with the fact
that tanker GM's when loaded are normally VERY high, the degree of change in
ride, be it comfort or submergence due to water temps in salt water, will
not be noticed.

otn