What does BB mean for a navy ship?

Answer 1

Prior to 1920, the USN used the designations B for battleship and then a hull number, such as B-1, B-2, etc. Same for destroyers, etc. D-1, D-2, etc. After WW1 (1918) a wider variety of naval vessels began to enter the USN inventory...blimps (airships/balloons), submarine tenders, salvage vessels, aircraft carriers (heavier than air vs airships), etc. Those vessels REQUIRED more than one letter, such as the aircraft carrier; the carrier (CV) was "C" for carrier and "V" for heavier than air (airplanes, not balloons). So, for paper work purposes, two letters were needed to maintain consistency and uniformity. Without such an organization, confusion would result. In 1920, the new designation for battleships and destroyers became BB & DD; "B" for battleship and "D" for destroyer, the second letters "B" and "D" meant nothing, other than making battleships and destroyers easier to document during administrative functions.