When completed in 1845, Great Britain was a revolutionary vessel—the first ship to combine an iron hull with screw propulsion, and at 322 ft (98 m) in length and with a 3,400-ton displacement, more than 100 ft (30 m) longer and 1,000 tons larger than any ship previously built. Her beam was 50 ft 6 in (15.39 m) and her height from keel to main deck, 32 ft 6 in (9.91 m). She had four decks, including the spar (upper) deck, a crew of 120, and was fitted to accommodate a total of 360 passengers, along with 1,200 tons of cargo and 1,200 tons of coal for fuel.