Thanks beejay. Alpha, Bravo, and Yankee are also damage control conditions. In the Canadian Navy all equipment, off centre-line guns, power panels, etc are odd numbered on the Starboard side & even numbered on the Port side. This convention is explained in the 'Admiralty Manual of Seamanship (BR67-1 Ch1)'. When I went through 'Cannon College' in the 70's we were taught that gun mount Z (not necessarily a turret) was a designation for a experimental or temporary, mission specific, fitted weapon.