OK Edgar,
I'll ask the question. On internal ballast; are you talking about the
weight of the ballast itself or are you talking about the weight of the
water that the "Internal Ballast" caused to be DISPLACED.
Also; What are you referring to when you say " Displacement 'tonnage"
What are you weighing? Ballast or displaced water? Displacement Tunnage
(correct spelling) is a Volume measurement.
As Ellen stated, Displacement "Tonnage" should be "Tunnage" a Volume
measurement. Hull Displacement is the weight of the water displaced by
the hull
There are two DIFFERENT DISPLACEMENTS mistakenly being described by a
single term
http://community.webtv.net/tassail/ThomPage
http://community.webtv.net/tassail/ILLDRINKTOTHAT