HMS Ajax (1912) - Armament

Armament

The main armament consisted of ten 13.5 inch (343mm)) 45 calibre Mark V guns, disposed in five twin turrets all on the centre-line of the ship. The turrets were identified with letters, as was the general naval custom. "A" turret was situated on the forecastle; "B" was immediately aft, one deck higher and in theory superfiring over "A". "Q" turret was placed amidships, at maindeck level, between the after funnel and the aft superstructure. "X" was placed on the quarterdeck immediately aft of the after superstructure, at the same level as "A" turret; "Y" was immediately aft of "X" and at maindeck level, allowing superfiring of "X" over "Y". In practice, because of the practice of positioning of sighting hoods on the turret crowns, firing of the superfiring guns directly over the lower turrets was found to seriously adversely affect the crew of the lower turret.

The maximum elevation of the guns was 20 degrees, which was an increase over previous dreadnought classes. The arcs of fire of "A", "B", "X" and "Y" were all stated as 300 degrees, although it was recognised that firing too close to the superstructure would cause significant damage to it. "Q" turret was also stated to have an arc of fire of 300 degrees, on the basis that at full elevation its shells would pass over the after superstructure. At anything less than full elevation the arc of fire was about 115 degrees on either beam; again, with the risk of causing blast damage if firing too near either the fore or after superstructure.

The guns fired a shell weighing 1,400 pounds, and the maximum rate of fire was two rounds per gun per minute, although to allow for the spotting of the fall of shot one round per minute was more usual.