Question: was the lusitania the sister ship of the titanic

Answer: No, RMS Lusitania was a British ocean liner that a German submarine sank in World War I, causing a major diplomatic uproar. The ship was a holder of the Blue Riband, and briefly the world's largest passenger ship until the completion of her sister ship Mauretania. The Cunard Line launched Lusitania in 1906, at a time of fierce competition for the North Atlantic trade. She made a total of 202 trans-Atlantic crossings.