This article sets out the workings of the British 14in quadruple turret as fitted to the King George V class battleships of the Second World War. The article is sourced from ADM 234/271 Handbook for the 14-inch, B.L., Mark VII Gun on Twin, Mark II, and Quadruple, Mark III Mountings.

These were complicated mountings, with more than 3,000 working parts and a training mass of 1,550 tons. The article tracks the path of the ammunition from the magazines deep in the ship to the point that the guns are loaded and ready to fire. Details are specific to 'A' mounting for the purposes of illustrating the workings in detail - differences in 'B' and 'Y' turrets are touched upon at the end.

At the bottom of ‘A’ turret is the Magazine Handing Room, which is where cordite is transferred from the magazines to the ammunition hoists. This is located in the deepest part of the ship, at the Hold level, just above the double bottom. The Handing Room itself is square in shape, and it’s surrounded by magazines forming a rectangular complex.

The Handing Room is surrounded by a total of 8 magazines, where the cordite is stored for ‘A’ turret. These magazines contain a total of 821 cordite cases, each case containing two quarter charges (four charges are required for a full charge).

   'A' Forward Magazine - 171
   'A' Port Magazine - 167
   'A' Starboard Magazine - 177
   'A' Main Magazine – 134
   'A' Port Wing Magazine – 33
   'A' Starboard Wing Magazine – 20
   'A' Port After Magazine – 66
   'A' Starboard After Magazine – 53

Cordite is embarked on to the ship via two hoists, located at opposite corners of the magazine complex. One is at the forward end on the port side and opens into the Forward Magazine. Transporting rails allow cases to be distributed into the Port Magazine and Port Wing Magazine as well. The other cordite hoist is at the aft, starboard corner and opens into the Starboard Wing Magazine. Transporting rails provide connection with the remaining magazines.

From inside the Handing Room there are 4 doors into the magazines – into Forward, Port, Starboard and Main. Each opening actually has 2 doors – an inner watertight door and an outer flash tight door. The deckhead and bulkheads of the magazines, including those between the magazines and Handing Room, have 60 lb (1.5”) of 'D' Steel bolted to them to protect against splinters from shell hits.

To load the guns, a quarter charge is removed from the cordite case within the magazines and placed on the nearest roller chute. It is then run along the chute to the nearest cordite lift, of which there are 4 in total. These exist to pass charges from the magazines to the Cordite Handing Room. It is then placed in the waiting cage through the lower flash door, a sailor then presses a foot pedal to raise the cage. As the cage rises a counterweight closes the lower flash door, the upper flash door is opened by contact with the ascending cage. At Handing Room level, the flap of the cage is opened and the quarter charge then rolls out into the Waiting Tray within the Handing Room. The cage descends, gravity closing the upper flash door behind it and contact with the lower flash door opening it ready for the next charge. An indicator is placed within the magazine to say whether the waiting tray is "Empty" or "Loaded".

Within the Handing Room, sailors pick up the quarter charges from the Waiting Trays and place them in the Loading Trays on the cordite hoppers. There is one cordite hopper for each gun. The inner guns are served from the front of the platform and the outer guns from the rear of the platform. The hopper consists of two scuttles, one above each other, that are side loaded. Each scuttle contains two charges – thus the hopper holds four charges at once, a full charge. With the charges placed in the loading trays, the scuttles are rotated through 120 degrees and become flash tight from the handing room. There are drenching nozzles in the hopper to soak the charges if required. Operation of the drenching valve in the cordite handing room will drench all the charges in the cordite hoppers and hoist cages simultaneously. The charges are then rammed into the Cordite Cage in the central ammunition hoist. The Cordite Cage, like the hopper, has two horizontal tubes, each containing two quarter charges.

Above the Cordite Handing Room and Magazines are the Shell Rooms. Access to the Cordite Handing Room is via a hatch in the Shell Handing Room. Like the rooms below, there is a square Handing Room surrounded by multiple shell rooms. The shell rooms contain 392 rounds of APC (98 rounds per gun) and 40 practice rounds (10 rpg), distributed as so:

   'A' Forward Shell Room – 98 APC and 4 Practice
   'A' Port Shell Room – 108 APC
   'A' Starboard Shell Room – 108 APC
   'A' After Shell Room – 78 APC
   'A' Outer After Shell Room – 36 Practice

Like the cordite, shells are embarked via two hoists. These are located at the opposite corners than the cordite hoists – i.e. the forward starboard corner and the aft port corner. Shells are lowered vertically and stored horizontally.

There are overhead rails to transport the shells between the embarking gear, shell bins, and the shell waiting trays. Shells are picked up via a shell grab, which consists of two forks. Shells are lifted via a hydraulic lifting press. A set of hydraulic traversing gear then moves the shell to the nearest shell waiting tray, where the hydraulic lifting press is used to lower them again. There are two sets of traversing gear per main shell bin.

Each of the four main shell rooms (excluding here the Outer After Shell Room, which just contains practice rounds) has four shell waiting trays which face onto the Shell Handing Room. From the point of view within the Shell Handing Room, these on the forward, aft, port and starboard bulkheads, in the middle. The shell waiting trays are separated from the Shell Handing Room by watertight doors. Once the waiting trays have been loaded, projectiles are rammed through the watertight doors into the shell handing room and onto the revolving shell ring via a set of 'hinge trays'.

The revolving shell ring can be driven from either the ship or the mounting. Allowance is made for a 1-inch rise or fall of the ship in relation to the mounting on both the rack and roller path. The shell ring is aligned with the ship to allow shells to be loaded – a full load is 16 shells, 4 from each main shell room. The revolving shell ring can then be aligned with the mounting to enable 4 of those shells to be rammed into the central ammunition hoist.

To ram the shells into the central ammunition hoist, the control lever is moved to "Open Flash Doors". This opens the flash doors between the trunk and the handing room and moves the telescopic Shell Arrestors into the Out position. When the control lever is moved to "Ram" a stop bolt is inserted behind the arrestor. The shell is then in position with the nose clear of the shell cage, the bolt and arrestor are withdrawn, and the cage can rise.

At the Battle of North Cape, due to the heavy movement of the ship, these rammers were being worked carefully to avoid ramming shells into the arrestors with too much force. A roll and heavy lurch in the ship coincided with the ramming of the shells. The rammers were stopped but the shells had "taken charge" and ran into the shell arrestors. However, the stop bolt was not in position prior to the shell noses impacting the arrestors and the arrestors collapsed into the In position. The shells thus projected beyond the shell cage and so it couldn't rise. This effected No. 1, 3 and 4 guns in 'Y' turret. It took 15 minutes to force the shells back into the cages and reset the arrestors.

The system was modified after North Cape to introduce a hydraulic buffer cylinder behind the shell arrestor rather than a stop bolt, which was capable of taking more force if shells were being rammed on the incline. An interlock was introduced to ensure that ramming could not take place prior to the buffer being in position.

The shell cage and the cordite cage are raised simultaneously up the central ammunition hoist to the working chamber. They arrive together, stacked atop each other. The shell is at the top, with two cordite charges in a "tube" below and two more cordite charges in a second lower "tube". An interlock prevents the cages being raised unless the flash doors on the trunk in the shell and cordite handing rooms are closed.

At the working chamber, shells and cordite charges are rammed forward onto traversers. The traversers move the shells and cordite horizontally from the central stalk to be in line with the guns. The shell and cordite are rammed from the central ammunition hoist to the traverser simultaneously. The first motion of the control lever opens the flash doors separating the central ammunition hoist from the traversing compartment. As the flash doors fully open, an interlock is withdrawn, enabling the control lever to be moved to "ram". When the ramming stroke is completed the lever is moved to "withdraw", once the rammer head is clear of the flashdoors an interlock is withdrawn and the lever is moved to "close flashdoors". Drenching nozzles are positioned to drench the charges in the traversers, initiated by the Captain of Turret operating the emergency handle in the gunhouse (the 2nd Captain of Turret has an alternative way of drenching the charges if needed).

The traversers move on rails mounted in the floor. The shells / cordite are then rammed backwards over a bridge tray into the gun loading cage. There is a set of flash doors between the bridge tray and the well of the gun loading cage.

With the gun loading cage lowered into the well, it forms a complete seal between the working chamber and the spaces above. The flash doors between the bridge tray and the well are then opened, as are the flash doors on the front of the gunloading cage. The shell and cordite is then rammed into the gun loading cage and the flash doors closed. The charges within the gunloading cage when at working chamber level cannot be directly drenched, so sprayer pipes and jets are position to drench the outside of the cage to keep them cool. As with the drenching of charges in the traversers, this is done by the Captain of Turret operating the emergency handle.

The cage is then raised hydraulically to the 'RAM SHELL' position. A flash door on the rear of the shell compartment is opened and the shell rammed into the gun's breech. The cage then rises for the first cordite ramming position. The flash doors at each end of the cordite tube are opened and the two charges rammed. The cage then rises to the second cordite ramming position and the process is repeated. The gun loading cage then descends under its own weight back to the gun loading well in the working chamber. The gun is now loaded and ready to fire. The Captain of the Gun can drench the cordite in the gun loading cages at gunhouse floor level by operating a drenching valve within reach under the gunhouse roof.

The Central Ammunition Hoist has a 26 second cycle time, the Traversers in the Working Chamber a 17 second cycle time, and the Gunloading Hoist (including elevating / depressing the gun to from 5 to 20 degrees) a 30 second cycle time. Hence a nominal maximum rate of fire of 2 rounds per minute.

The local control position is between the two inner guns, near the front of the gunhouse. A look-out periscope is provided at this position. The main training position is in front of the local control position and has a telescopic sight. An auxiliary training position is located between the two right guns. This does not have a telescopic sight, but does have a follow-the-pointer receiver. The layer's position is located between the two left guns.

There is a 42 ft rangefinder at the rear of the turret. The projecting ends are protected by armour quality castings 3in thick.

There is a Navigating Cabinet at the rear of the gunhouse. This has a periscope capable of all-round training coupled to a pointer in an azimuth repeater instrument. The Conning Officer has a rudder indicator, steering order transmitter, and a speed indicator, as well as communication telephones. Next to the telephone operator there is a change over switch with 4 positions - (1) lower steering position, (2) after steering position, (3) 'X' engine room, and (4) off.

There is a 'silent cabinet' in the turntable compartment. This contains an Admiralty Fire Control Box Mark IV for use in local control. Firing of the guns can be controlled via one of three positions - Director control tower, "B" turret, or Local.

The gunhouse armour is as follows:

   Front – 520 lb (12.74in)
   Front side – 360 lb (8.82in)
   Rear side – 280 lb (6.86in)
   Rear – 280 lb (6.86in)
   Roof – 240 lb (5.88in)

Where the 3in thick turret floor plate projects beyond the front of the turret, a 200 lb (4.90in) plate is fitted.

There are 10in thick balance plates on the rear armour plate.

Vent holes are provided through the rear armour and balance plates, covered by vent plates on the outside. These vent plates are designed to blow off if the pressure in the gunhouse increases excessively due to an explosion.

'Y' turret was also a Mark III mounting, although it did have some differences from 'A' turret. 'Y' gunhouse did not have a Navigating Cabinet, this being unique to 'A' turret. The balance plates on the rear of the turret were reduced to 8in thickness, due to the presence of an Octuple Pom Pom on the turret roof. While 'A' mounting had four cordite lifts used to pass ammunition from the magazines to the handing room as described above, 'Y' turret had two cordite lifts and two flashtight scuttles due to reduced space at the aft end of the ship. In these scuttles, a quarter charge was pushed through an open flashtight door into the scuttle itself, and the use of the operating lever closed the magazine-side flashtight door and opened the handing room-side flashtight door. 'Y' magazines contained 880 cases of cordite ammunition. 'Y' shell rooms contained 412 rounds of APC and 40 rounds of practice ammunition.

'B' turret was the Mark II. In most respects this was a Mark III turret without the equipment for the outer guns, but there was some re-arrangement to suit the smaller size. The rangefinder was reduced from 42 ft to 30 ft, but a duplex model was fitted as 'B' turret also served as the tertiary fire control position. The local control position was in the 'Silent cabinet', which was on the left hand side of the gunhouse rather than in the turntable compartment. The balance plates on the rear were 3in thick, and there was no sill plate as the gunhouse floor did not project forward of the faceplate. 'B' magazines contained a total of 432 cases of cordite, and 'B' shell rooms contained 196 rounds of APC and 20 rounds of practice ammunition. 'B' turret had a training mass of 898 tons.

27 November 2023 - New Essay