In March 1940, "Queen Mary" and "Normandie" were joined in New York by "Queen Mary" new sister ship , fresh from her secret dash from Clydebank. The three largest liners in the world sat idle for some time until the Allied commanders decided that all three ships could be used as troopships. "Normandie" was destroyed by fire during her troopship conversion. "Queen Mary" left New York for Sydney, Australia, where she, along with several other liners, was converted into a troopship to carry Australian and New Zealand soldiers to the United Kingdom.