Updated 01 August 2008

4.7"/45 (12 cm) Mark IX gun in CPXVIII mounting
This mounting was used on H, I and most war emergency destroyer classes
After the tray worker (on left farthest from the camera) pushed the loading tray over, the rammer man (not in picture) then hauled on the "T" handle to move the projectile and cartridge into the breech after which the breech worker (on right) closed the breech.  After the gun fired, the tray worker reset the rammer head by pulling it back to the rear of the loading tray.  The net laying on top of the counterweight normally hung down so as to slow the ejected cartridge case.
MoD Photograph

The last 4.7" (12 cm) Center Pivot Mounting, the Mark XXII
Note the differences between this late-war mounting and the pre-war one shown above.  Although this mounting has major improvements over the earlier one, the difficulty in working this gun at or near its maximum elevation of 55 degrees is apparent.

The tray worker is leaning over the fuze-setting machine, used for AA projectiles.  The loading tray operation was automatic, but this required very careful adjustment in order to ensure that the rammer head tripped at the proper time.  This mounting was nearly identical to the ones used for the 4.5 in (11.4 cm) Mark IV guns and they shared the same maintenance manual.

HMS Jupiter
 4.7"/45 (12 cm) Mark XII guns in Mark XIX mountings
Note that the twin mounts are open-back and that a 4"/45 (10.2 cm) Mark V HA gun has replaced the after set of torpedo tubes
IWM Photograph

4.7"/45 (12 cm) Mark XII guns on HMCS Huron
Photograph courtesy of the Naval Museum of Manitoba

4.7" gun from Argentine Buenos Aires Class Destroyer
Photograph copyrighted by Georg v. Rauch and used here by his kind permission

4.7" gun from Argentine Buenos Aires Class Destroyer
Counterweight is missing from this gun
Photograph copyrighted by Georg v. Rauch and used here by his kind permission

Argentine Destroyer Entre Ríos
Photograph courtesy of Georg v. Rauch

British 4.7" (12 cm) SAP Projectile
Image courtesy of Steve Johnson of Cyberheritage

Starshell for 4.7" (12 cm) guns
Picture courtesy of Bob Henneman
All the World's Battlecruisers

Note the Rammer Handle and Balance Weight
Sketch from The Gunnery Pocket Book, B.R. 224/45 (1945)
Used here by permission of Historic Naval Ships Association

Click on this sketch for a larger image
Sketch from The Gunnery Pocket Book, B.R. 224/45 (1945)
Used here by permission of Historic Naval Ships Association

4.7"/45 (12 cm) Vickers "E" gun formerly on Chilean destroyer of the Serrano class
Mounting now at Museo de Cañones Navales in Bahia de Valparaíso, Chile
Photograph copyrighted by Carlos Mey and used here by his kind permission

4.7"/45 (12 cm) Vickers "E" gun formerly on Chilean destroyer of the Serrano class
Mounting now at Museo de Cañones Navales in Bahia de Valparaíso, Chile
Photograph copyrighted by Carlos Mey and used here by his kind permission

4.7"/45 (12 cm) Vickers "E" gun formerly on Argentine destroyer of the Mendoza class
Mounting now on display at Museo Naval de la Nación, Buenos Aires, Argentina
Photograph copyrighted by Carlos Mey and used here by his kind permission

Images at The Vickers Photographic Archive

For the Mark IX:  4.7 Mark VIII, Single Mark XIII quarter and XXII
Notes:  "Mark VIII" is a misprint, the mountings shown here were actually Mark CPXVIII

For the Mark XII:  4.7 XIX
Although identified as 4.7" (12 cm) guns, photographs 4797 and 5853 at the Vickers Archives are actually of 4.5" (11.4 cm) twin mounts

For the "wet-mount" 4.7" (12 cm) Mark IX guns used on submarines:  Thames deck gun

For the Mark IX or "E" Export Version: Single Mark IX Chilean and 4.7 Field Gun
Some of these photographs show weapons with abbreviated shields and have a "1929" date.  Although these are identified as Mark IX guns, I believe that they are actually Vickers "E" type 4.7" (12 cm) guns.  Note in these photographs that although this gun had high-angle capability, doing so meant that the loading apparatus was below the gun deck level.  This means that either these guns could not actually be used at high elevations or that there needed to be a gun well around the mounting.