I have a highly technical way of assessing total volume of complicated shapes like this -

i) Look at the thing, mentally you put it in a rectagular box that just fit sidewards/length,

ii) Mixmaster the whole thing, and let the volume sludge down so that it fills the box

iii) Eye level the height of the resulting sludge. You now have a simple box to do a vulme calculation

Looking at your plan, if it's 5 stories high, I reckon it would pulp to arround 1 1/2 stories.

So 300ft long * 100ft wide * 20ft high -> 600,000cubic feet. Of this only 80% of the interior is usable (it's streamlined) but the whole thing contributes to volume. I make that to be 1200 tons. A little big, but well within bounds for an eyeball result.

If you want an accurate figure, then either chop it up into sections you can measure (ie put lots of numbers for the angles and edge lengths) or make one out of something (ie plasticine) and imerse it in water to give you an accurate displacement volume.

If you do the second of these, I would recommend you do it to scale rather than full size - but full size would have a variety of addition benefits so it can't be discounted (Live action RPGs onboard a full scale frigate). Plasticine probably isn;t the best idea for a 5 story high self supporting structure - but what do I know.

Paul

The Difference between Practise and Theory is bigger in Practise than it is in theory