Atlantic telegraph cable laying. SS Great Eastern laying the 1865 Atlantic telegraph cable. The third of the large ships designed by Isambard Kingdom Brunel, at 212 metres in length and displacing 19,000 tons, it was the largest ship in the world when launched in 1858, and remained so for 40 years. The ship was large and powerful enough for the task of laying a telegraph cable on the ocean floor. It laid 4200 kilometres across the Atlantic, and a further 48,000 kilometres of submarine telegraph cables between 1866 and 1878. Artwork from 'Electricite' (1911) by Max de Nansouty, part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.