"Great Britain"
Designed by Isambard Kingdom Brunel, the "Great Britain" was completed in 1843 and goes down in history as a ship of firsts. It was the first ship to be made from iron, it was the first to use the double hull design and it was the first to use a screw propeller. It was also the largest ship ever built at the time, (320 feet long, 50 feet wide displacing 3,500 tons)and was only superceded by another of Brunel's ships, the "Great Eastern" which was launched in 1857 (692 feet, displacing 28,000 tons)
Sources: "What the Victorians Did For Us" by Adam Hart-Davis. Picture: courtesy of the Cape Town Archives