The first Trident boat, , collected a full load of 16 missiles in 1994, but the second, drew only 12 in 1995, and the third, , 14 in 1997, leaving the remaining missile tubes empty. Although the UK designed, manufactured and owns the warheads, there is evidence that the warhead design is similar to, or even based on, the US W76 warhead fitted in some US Navy Trident missiles, with design data being supplied by the United States through the MDA.