SS Great Britain is a museum ship and former passenger steamship, which was advanced for her time. She was the longest passenger ship in the world from 1845 to 1854. She was designed by Isambard Kingdom Brunel for the Great Western Steamship Company's transatlantic service between Bristol and New York. While other ships had been built of iron or equipped with a screw propeller, Great Britain was the first to combine these features in a large ocean-going ship. She was the first iron steamer to cross the Atlantic, which she did in 1845, in the time of 14 days.

The ship was 322 ft (98 m) in length and had a 3,400-ton displacement. She was powered by two propeller engines of the direct-acting type, with twin 88 in (220 cm) bore, 6-foot (1.8 m) stroke cylinders. She was also provided with secondary sail power. The four decks provided accommodation for a crew of 120, and 360 passengers who were provided with cabins and dining and promenade saloons. The ship is now berthed in the dry dock where she was first built, this view is taken across the 'Floating harbour'. The harbour was the subject of alteration work by Brunel in an effort to reduce its silting and is another indication of the diversity of Brunel's considerable engineering talent. photo 1992. ©John Chalcraft/www.railphotoprints.co.uk