When it was still a sea going vessel the Queen Mary had four props like this one & each one weighed 35 tons & was twenty feet long. Only this one is still on the ship, which is now in it’s permanent home, in Long Beach Harbor. Construction began on the Queen Mary on December 1, 1930 in Clydebank, Scotland and it’s maiden voyage was on May 27, 1936. The gorgeous & historic ship is now a huge part of the culture in Long Beach, CA & is used as a hotel & has wonderful ballrooms for parties, etc.