Q Class or Class Q may refer to: Locomotives GNRI Class Q, a Great Northern Railway of Ireland locomotive class NZR Q class (1878), a New Zealand Railways locomotive class NZR Q class (1901), a New Zealand Railways locomotive class SR Class Q, a British Southern Railway locomotive class WAGR Q class (diesel) Other uses Library of Congress Classification:Class Q -- Science Q-class destroyer, a class of warships used by the Royal Navy, Royal Netherlands Navy, and Royal Australian Navy Classical Quarterly, abbreviated Class. Q.