The White Star Line's vessels were almost longer and slightly wider than "Lusitania" and "Mauretania". This made the White Star vessels about 15,000 tons larger than the Cunard vessels. Both "Lusitania" and "Mauretania" were launched and had been in service for several years before "Olympic", and "Britannic" were ready for the North Atlantic run. Although significantly faster than the "Olympic" class would be, the speed of Cunard's vessels was not sufficient to allow the line to run a weekly two-ship transatlantic service from each side of the Atlantic. A third ship was needed for a weekly service, and in response to White Star's announced plan to build the three "Olympic"-class ships, Cunard ordered a third ship: . Like , Cunard's "Aquitania" had a lower service speed, but was a larger and more luxurious vessel.