-Each Vanguard can carry up to 16 Trident II missiles, with a limited load of 48 nuclear warheads. The submarines are powered by nuclear propulsion, allowing them to operate for extended periods.

Some 16 Trident II D5 missiles can be carried by each submarine, and each can carry up to 12 independently-targeted warheads with a maximum range of 7,400 miles.

Comparably, the two atomic bombs the U.S. dropped on Japan during the Second World War were 15 and 20 kilotons. Trident II is a three-stage solid-propellent missile with supersonic speed.

The weapons manufacturer first delivered the Trident II in 1990 to the U.S. Navy for its Ohio-class submarines as well as the British Royal Navy's Vanguard-class sub.