BL 9.2 inch Mk XI naval gun

The BL 9.2 inch gun Mark XI 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 :
 * Minotaur-class armoured cruisers laid down 1905 & completed 1908 - 1909 : 2 twin mounts.
 * Lord Nelson-class battleships laid down 1905 & completed 1908 : 4 twin mounts and 2 single mounts.

After the scrapping of the ships above, these guns and mountings were retained in storage, the intention at one point during early 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 planning stages.