On Sun, 17 Jan 2021 06:48:54 +0000 (UTC), xxxxxx@yahoo.com.au
wrote:

>The second relates to the colonial transport 'Anniversary' I thought I
>might try and design it. The only clues I have is that it's a 600,000
>ton ship that carried 500,000 colonists and their supplies/equipment.

This sounds like it's too small or overcrowded; each colonist plus
their supplies gets barely over one dton of cubage. That includes
space for their body. Even if the colonists are corpsicles at 0.5dt
per low berth, that's not a hell of a lot of supplies per colonist.

>The tonnage falls right between the tonnages in High Guard that go up
>in odd increments. I'm not sure how to resolve this so I he one of the
>more experienced ship designers out there can help someone who is a
>rank amateur at this.

Which High Guard are you trying to design under? It _will_ make a
difference. However, my rule of thumb - which contradicts RAW - is
that if your tonnage is not more than 10% over a table entry, you can
use that table entry for drives and powerplant. However, the cost of
that is any task involving the drives or powerplant is automatically
at DM-1 in addition to any other DMs. If you don't want that, you need
to go to the next size up on plant and drives when you spec out the
ship. (The reason for the DM is that you're cutting into any built-in
safety margins.

(RAW generally seems to say that if your specs say X+1 dt, you need to
use the next entry on the table, period. The "allowance" is only for
drawing deckplans.)