what does dd stand for in the navy
Hull classification symbol It is important to understand that hull number letter prefixes are not acronyms, and should not be carelessly treated as abbreviations of ship type classifications. Thus, "DD" does not stand for anything more than "Destroyer". "SS" simply means "Submarine". And "FF" is the post-1975 type code for "Frigate."[6]
USS New York (LPD-21) USS New York (LPD-21), the fifth San Antonio-class amphibious transport dock, is the fifth ship of the United States Navy to be named after the state of New York.[1][2] New York has a crew of 360 and can carry up to 700 Marines. A symbolic amount of steel salvaged from the World Trade Center after it was destroyed in the September 11 attacks was used in her construction.[1]