the ship was improved. Each crew member was given their own bunk. The space was also used for generating machinery required by for anti-submarine warfare. This machinery was changed from three steam and one diesel to two steam and two diesel generators. The quarterdeck was enclosed to house two Squid anti-submarine mortars. A much larger bridge structure was installed that was almost entirely enclosed. The upper works were constructed of aluminum instead of steel to save weight. This necessitated a heightened funnel to clear the new structure, which in turn required a larger mast. This mast remained a tripod. The propelling machinery was overhauled and the hull forward was strengthened forward to protect against ice. One ship, Buckingham, had a flight deck attached aft for helicopter landing and takeoff sea trials, but the structure was removed once the trials were completed. Ships References Notes External links Prestonian-class frigates – hazegray.org Frigate classes Frigates of the Royal Canadian Navy River-class frigates River-class frigates of the Royal Canadian Navy