I don't know what mechanism to suggest to you to use. The fleet is subjected to defensive fire from the port 2. The fort is subjected to fire from the fleet 3. The fleet attacks targets within the harbor 4. The fleet withdraws, subject to fire from what is left of the fort.
Shipyards have limits as to how many ships they can produce based on historical capacity.
D. Naval Stores - represent the various types of lumber, tar , pitch and the like necessary to construct, repair, and maintain ships. Trans-shipment of stores may be interecepted and captured or destroyed by England.