Launched in 1858, the Great Eastern was the largest steamship in the world until surpassed by the Oceania in 1899. It was 211 m (693 ft) long and propelled by paddlewheels, a propeller, and six auxiliary sails. It is best remembered for laying the first trans-Atlantic telegraph cable the year it was launched. Here, a supply ship loaded with cable pulls up alongside the Great Eastern.
Brunel combined elements from the Great Western and the Great Britain in his third and final ship, the Great Eastern, which launched in 1858
Iron-hulled and propelled by a combination of paddlewheels and screw propellers, Great Eastern dwarfed even the largest ships of the day. Before Great Eastern, the longest ship afloat measured 114 m (375 ft) and 3,300 tons. Great Eastern stretched 211 m (692 ft) in length and measured 19,000 tons. Despite its gargantuan proportions, the ship failed as a passenger liner. It went on to lay the first transatlantic electric telegraph cable.
Nonetheless, the Great Eastern proved a trendsetter. Following Brunel's lead, most shipbuilders constructed ships from large iron plates riveted together. Iron ships had stiffer hulls, which helped to reduce vibration from the movement of the long propeller shaft. But iron presented a new set of challenges to builders. Iron was rigid, it fractured easily, and it rusted. Shipbuilders found an alternative in steel, a mixture of iron and other elements, which is stronger and easier to shape than iron. Steel's exorbitant cost and relative scarcity made it an impractical choice until 1855, when English inventor Henry Bessemer improved the steel refining process. The Bessemer process made good quality steel available at a fraction of its earlier price. By the end of the 19th century, most of the great merchant and battleships featured steel hulls.