Aft Magazines and Shell Rooms
Magazines and shell rooms are situated forward and aft of the armoured citadel, and placed low down in the ship. In the aft of the ship, at the level of the platform deck (just above the double bottom, and as low as you can get), there is a lower magazine.
"Magazines are constructed as watertight iron tanks, lined with wood, the lining not being in contact with the iron. There is an apparatus by means of which they may be flooded so that an external fire will not endanger the powder within. The powder, if the cases are properly closed, should not be injured by admission of water to the magazine.
Magazines are lighted from the outside and the light given is usually quite sufficient for working the magazine in action, but if required to read labels etc. some description of reflector must be generally used". i.e. it is very dark in there!
Most magazines have a ventilation machine fitted. 
For the purposes of this web page, the magazine tanks are not generally shown, or are shown as low barriers.
The lower aft magazine can hold 27 charges (7,965 lbs) of Prismatic Brown powder, although due to the difficulty of access, these spaces would normally be filled with spare powder of all descriptions.
The deck above, the Lower Deck, accommodates the two main Magazines and two Shell rooms. Shells and powder cases are lifted to the gun deck via two lifts at the forward end. These lifts emerge within the armoured citadel. Interestingly, the two shell rooms share a common corridor and shells / powder may be hoisted on either lift. This is not the case with the forward magazines and shell rooms.
In the Shell room, the shells themselves would be segregated into separate bins using wooden slats, which are not shown here.
Shells and powder cases are moved using overhead tracks leading from the shell rooms and magazines to the hoists. In a seaway, it would be very dangerous to try to move a 715 lb. shell in a trolley along the deck.
The forward magazines are formed of two tall magazine tanks separated by watertight bulkheads (not shown). These magazines reach from the platform deck through to the lower deck.
Shell rooms are sited on the lower deck. The two lifts feed to the front end of the armoured citadel gun deck. However, each lift serves one magazine or shell room. If a lift fails, the shell room and magazine are effectively cut off.
The point to note is the long distance a shell has to be manhandled from the shell room to the lift. This is a contributing factor to the slow rate of fire. However, it was common naval practice to keep ‘ready use’ shells on the gun deck. These would be the less sensitive shells, such as the Palliser or other Armour Piercing shell that has a small bursting charge.
Regulations prevent more than two or three powder cases per gun from being moved up to the gun deck at any one time.
(c) Rob.b1904 2008