Known as Turtle, the world's first military submarine appeared during the American War of Independence. It was 10 feet long, constructed of two wooden shells covered with tar, propelled by a one-person crew using hand-cranked propellers, had enough air for a 30 minute dive and its weapons were a drill, a keg of gunpowder and a time fuse. Fast forward 230-odd years to the British Navy's Astute class submarine, which is currently undergoing sea trials, and you get a very different picture. Made up of a million individual components and capable of carrying 93 crew and an array of weapons including Tomahawk cruise missiles, the nuclear-powered Astute class is 97m long, weighs 7,800 tons, is coated in 39,000 sonar masking acoustic tiles and doesn't need refueling throughout its expected 25 year service life.
Read the full article: Britain's most advanced attack sub ever on sea trials