SS Atrato

SS Atrato was a 3,184-ton iron-hulled side-wheel paddle steamship built in 1853. She has been listed as being the World's largest passenger ship from 1853 to 1858.

Caird & Company of Greenock on the Firth of Clyde built Atrato for the Royal Mail Steam Packet Company (RMSP), which ran her between Southampton and Buenos Aires for 17 years. In 1870 RMSP sold her to John Morrison & Co of London, who converted her into a single-screw vessel with compound engines fed by three double-ended boilers. She was still in service in 1888.