The BL 9.2-inch Mark XI gun was a British 50 calibre high-velocity naval gun which was mounted as primary armament on armoured cruisers and secondary armament on pre-dreadnought battleships.

History

The gun with its increased length of 50 calibres was an attempt to extract a higher velocity, and hence more range and armour-piercing capability, from the 9.2-inch gun. Like other British 50-calibre guns of the period, it was relatively unsuccessful and was the last model of 9.2-inch gun Britain built. Guns were mounted in the following ships : After the scrapping of these ships, these guns and mountings were retained in storage. There was the intention, at one point, early during World War Two, to use them as armament for small monitors which would have been reduced versions of the Roberts-class monitors; this however never advanced beyond the planning stage.