Did you add more planets as sponsors to that shipyard?  And as an example from my game, I am in turn 133 and my planet has about 54 ship production and a med ship takes 5 turns.  If I add more sponsors, I can get it down to 3 turns.

I'd say that the main problem with Crusades is the low base production. 

You can circumvent this with the second tier malevolent tech which gives the home world +10 or asteroids but the latter are a bit random. And if you want to get a good tech rate then the best way, if there are enough planets around, is to fill in the bottom line of the benevolent tree when the final item of +5 base research per planet is huge: but you need the whole line and this is hard to combine with the malevolent "treelet" at least early on. 

I understand that Durantium Refineries and for tech Thulium Data Archives massively skewed the base game but perhaps we could have some mid game building(s)  which provide base production.? In my present game, I'm 140 moves in or something (not on at this moment) and my main science planet is taking nine moves or so to build / upgrade each science building which seems a bit excessive. 

Cheers,

Jon

You need to surround the elevator and port with as many high adjacency boosts as you can.  You can get them up pretty high on your homeworld with galactic and player unique buildings adjacent to them and have a much much better score than 54.  Just with full rings of factories, that's 3 base and 12 leveled points of ship production.  Add another half dozen from asteroid mines and a few from population and you've already hit 20+ base production to work the percent modifiers against. 

With the right circumstances, you can create a super planet with a few hundred of each.  I quit one recent game in disgust because there were 16+ asteroids within +1 range of my homeworld, dozens more a little further out, and it had almost all of it's tiles grouped together.  I could have won without colonizing a single planet, just drop the Antimatter Powerplant in the center, with the various flat increase buildings around it and their corresponding capitals next to them.