"Lusitania"s keel was laid at John Brown on Clydebank as yard no. 367 on 17 August 1904, Lord Inverclyde hammering home the first rivet. Cunard nicknamed her 'the Scottish ship' in contrast to "Mauretania" whose contract went to Swan Hunter in England and who started building three months later. Final details of the two ships were left to designers at the two yards so that the ships differed in details of hull design and finished structure. The ships may most readily be distinguished in photographs through the flat topped ventilators used on "Lusitania", whereas those on "Mauretania" used a more conventional rounded top. "Mauretania" was designed a little longer, wider, heavier and with an extra power stage fitted to the turbines.