HMS Thunderer (1911) - Armament

Armament

The main battery consisted of ten 13.5” guns arranged in five twin turrets all mounted on the centre-line and enabled this class to fire a ten gun broadside without any risk of structural damage to the ship, problems still existed with the open sighting hoods of the lower turrets ( A & Y) in that to prevent muzzle blast of the two upper turrets ( B & X) entering the lower turrets via the sighting hoods, firing of the upper turrets was prevented from right ahead to 30 degrees on either bow for A turret and 30 degrees either side of right astern for X turret. The mid-ships turret was designated ‘Q’.

The 13.5” gun and was designated the Mark V L, the L indicating it fired the lighter of the 13.5” shells, later classes had the Mk VH guns which fired the heavier shells, the guns were just over 52 feet (16 m) long and the barrel alone weighed more than 70 tons each with a working pressure of 18 tons per square inch, construction was of wire winding, so good were these weapons that they were still in use during World War II as shore guns at Dover. Although just 1.5” larger than the earlier 12” gun it fired a shell weighing 1,266.5 lbs against the 859 lbs of the earlier gun, although of lower velocity than the 12 C50 gun the 13.5 C45 weapon’s heavier shell maintained it’s in-flight velocity and so had greater hitting and penetrative power, the new gun was also very accurate and possessed very good wear rates – up to 450 rounds per gun, tests also showed that the gun had a very good safety margin so that the following King George 5th class ships could fire an even heavier I,410 lb shell, although this lowered the wear rate to 220 rounds per gun.

Using a charge of 293 lbs of cordite ranges of just short of 24,000 yards were achieved at 20 degrees elevation, although this was of little real use, the gun range finders had been designed with closer ranges in mind and so could only work up to 16 degrees elevation. Used as a railway gun and using an elevation of 40 degrees the range was then 49,000 yards using 400 lbs of propellant; what this did to the wear rate is unknown.