In 1836, Isambard Brunel, his friend Thomas Guppy and a group of Bristol investors formed the Great Western Steamship Company to build a line of steamships for the Bristol-New York route. The idea of regular scheduled transatlantic service was under discussion by several groups and the rival British and American Steam Navigation Company was established at the same time. Great Western's design sparked controversy from critics that contended that she was too big. The principle that Brunel understood was that the carrying capacity of a ship increases as the cube of its dimensions, whilst the water resistance only increases as the square of its dimensions. This meant that large ships were more fuel efficient, something very important for long voyages across the Atlantic.