Superimposed turrets

[Sven]

Playing as the U.S. Had developed superimposed turrets ( both B and X); since GB started building BBs I thought great, let's start too.
but I couldn't build a ship with superimposed turrets. Was around 1907. Only wing turrets was possible ( kind of a Nassau design).
am I missing something?

[namuras]

Did you up the displacement? sometimes you need to pass a certain threshold to enable turrets of certain calibers. Also did you have 4+ centrelineturrets researched?

[fredsanford]

You still need the 4 centerline turret tech to go with the B and X turrets.

[Sven]

That's what I was missing.
Thank you!