On 17Nov2019 0859, Thomas RUX wrote:

> Yes, I found the entry that in "900 c Imperial Navy begins upgrading
> ships to jump-4. Spinward Marches Campaign, GDW, 1985, p. 32."
>

I just remembered that the IN fought the 3FW/SolRimWar at TL14.

That means that J5 capability was achieved well before 1000.
(The 'High Lightening' class of cruisers was J5 & were avail then)

Also, don't forget that all of the IN 'Regular' BatRon's in the 5FW boardgame are rated at J4.
Most of the CruRons too altho I do recall some with J5.
Don't recall any 'rons at J6.
Guess giving up 50% of total displacement to fuel is bad enough, which makes 60% just way too much.

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