Gunlayers Test:  2 rounds per minute
Battle Practice:  1 round per minute

1) Projectile weights from ADM 186/169.  The sources below disagree as to muzzle velocity, propellant charge weights and maximum ranges.  I have chosen to use those values given in "Jutland:  An Analysis of the Fighting."

2) Originally, 4crh projectiles were issued only to the Bellerophon and Indefatigable classes while the others used 2crh.  In 1915-16, 4crh were issued to Dreadnought and to the Invincible class.  "Greenboys" were issued starting in 1918.

3) AP Cap weights were 34.75 lbs. (15.7 kg) for the Mark VIa and 99 lbs. (44.9 kg) for the Mark VIIa.

4) This is the peacetime outfit which consisted of 24 APC, 40 CP and 16 HE all of which were 2crh.  APC and CP were black powder filled while HE was lyddite filled.  When the war started the outfit was increased to 110 rounds per gun in most ships.  When 4crh were issued to the Invincible class, the outfit was 33 APC, lyddite and black powder filled, 38 CPC and 39 HE, changed by mid-1916 to 44 APC, 33 CPC and 33 HE.  A few shrapnel rounds were carried during the war at times.  The final outfit for the Invincible class after the war was 77 APC, shellite filled, and 33 CPC.  The Indefatigable class carried a peacetime outfit of 24 APC, 28 CPC, 28 HE and 6 shrapnel.  The initial war outfit was 33 APC, 38 CPC and 39 HE, later changed to be the same as the Invincible class.

1) The BVIII* mountings on the Indefatigable class differed in that the gunshields were of modified shape and structure in an effort to improve protection.  The BIX and BX mountings on Invincible were interesting in that they were electrically powered by 200 Vdc from four 200 kW steam generators and 100 kW oil motor/generators within the ship.  These mountings proved unsatisfactory and were constantly breaking down during their active service life.  As a result, they were converted to all hydraulic power prior to the start of World War I.

2) These mountings were reworked during World War I to increase their maximum elevations to +16 degrees, a rather costly operation for the small increase in range thus achieved, which was less than 1,600 yards (1,460 m) at new gun velocities.

3) The Invincible class had staggered amidships mountings intended to allow them to shoot across the ship as well as directly forward and directly aft.  However, gunnery trials showed that the blast damage from such firings was unacceptable and the actual firing arcs were restricted to approximately the figures given above.  At the Falklands battle, Invincible fired cross-deck with both P and Q turret but this dazed and deafened the gun-layers, trainers and sight setters as well as causing blast damage to the deck.  P turret reported that the trainers had to be replaced constantly during the battle as they were too dazed to function properly.  After the battle, cross-deck firing was ruled out except in cases of emergency.

4) These mountings differed from earlier ones in that projectiles and propellants were rammed directly from the main hoisting cage into the gunloading cage without tipping out into an intermediate position.  This made for a simpler transfer but slowed the loading cycle as the main cage could not descend until the transfer had taken place.

5) Surviving battlecruisers had 1" (2.54 cm) armor plates added to their turret roofs following Jutland (Skagerrak).

6) Battle experience showed that British turrets in general were inadequately protected, especially on these early 12" (30.5 cm) models.  Problems included the lack of gunport shields, which meant that splinters and blast could easily penetrate into the working areas.  There were also large gaps between the base of the gunhouse and the top of the barbette, leaving an area of reduced protection.  The sighting ports on top of the turrets were of an open design, which allowed both gunsmoke and sea spray to enter into the gunhouse as well as causing considerable discomfit to the crewmembers whose job it was to peer through these ports at the target.  These sighting ports and the turret rangefinders also projected up above the turret roof, which unintentionally turned them into deadly shell traps.  Finally, the sloping front roof of these turrets meant that the angle of incidence for incoming shells was less than that for a flat roof, which increased the chance of a penetrating hit.