The Last 4.5” – to the Type 23 Frigate ST.ALBANS fell the honour of marking the bowing out of the Royal Navy’s main gun after 40 years’ service with the distinctive round Mod 0 gun – fitted to all Type 42 Destroyers, Type 23 Frigates and later Type 22 Frigates – has been the Fleet’s principal weapon against targets ashore.   The ST.ALBANS was the last Royal Navy warship fitted with the old gun – and it fell to the ship to fire the final round from the final round gun during training in Norway, making use of the NATO ranges near Bergen.     Originally designed as an anti-air weapon, the Vickers 4.5in Mk.8 gun, as it was originally known, was introduced in the early 1970s to replace the twin-barrelled Mk.6 gun, which traced its history back to the 1930s.    After successful trials the Mod 0 was first fitted on the Type 82 Destroyer BRISTOL.    The primary role of the gun was to provide Naval Gunfire Support against targets ashore, either to wipe out enemy positions, or fire for effect to demoralise the foe, but in its secondary role it can be used against surface ships.   The ST.ALBANS is the youngest Type 23 Frigate and thus the last in the class to undergo a mid-life revamp – when the round 4.5in gun will be switched for a “Kryten”, the newer gun, which is an electrical system with hydraulics only for ramming the round into the breach. The angular shape of the Mod 1 reduces its radar cross-section and the “Kryten” tag comes from the character in the television series “Red Dwarf”.