From what I can deduce, the only way into the pilothouse was from the turret. I haven't seen any indication of a ladder so I'm wondering if the captain and helmsman simply climbed up the gun carriage to get to the pilothouse.
I'm also guessing that the diameter of the pilothouse was about 6 to 8 feet and that the pilothouse remained fixed while the turret revolved underneath it.
thanks again.
chris