The Magazine at Watch House battery Plymouth dates from 1902 and served two six inch breach loading guns.
The Magazine is situated below and between the two gun emplacements, and still retains some original features.
Plans drawn up 16/03/40 to add a third gun to the battery give the capacity of the magazine as 1100 shells and 1100 cartridges with an extra 125 complete rounds on each gun emplacement stored in the shell and cartridge lockers above ground (WO 78/5058 PT3).
A grey painted marking ASL is on the floor of the cartridge store; its purpose is not known. The magazine is divided into two parts. The cartridge store at the back, protected by the greatest depth of rock, with the shell store at the front. The cartridge store is 60 feet long, the walls separating it from the shell store are 3 feet thick, the shell store is 9 feet wide and about 80 feet long. The ceilings of both stores are barrel vaulted and built of brick with maximum height of 8 feet 6 inches. The height at walls is 6 feet 6 inches. The wall between the shell store and cartridge store has 4 lamp recesses for lighting the cartridge store.
The shell store and cartridge stores are connected by a shiffting (sic) lobby, which originally had doors at each end. The wooden doors at the cartridge store end are still in place complete with original markings. The lobby has a row of wooden pegs. The magazine was ventilated by a Howarths Ventilation system (WO 78/5058 part 2) the pipes outside are still in place but the cowlings are missing. The exit holes for the ventilation system in the magazine ceiling are still visible
The shell and cartridge lifts are at the far ends of the shell store. Each emplacement had its own shell and cartridge lifts. The shell lift's original lifting mechanism has been removed. The photograph shows the handcranking mechanism of the type removed. The indents in the masonry where the mechanism was still exist.
The wooden guides are still in place; they are about 18 feet long and rise about 15 feet. The cartridge lifts are four feet wide and situated in the back wall. The entrance to the lift is supported by a 3 inch by 3 inch girder. The cartridge lift ascends vertically about 10 feet to the gun emplacement. The cartridge lifts still have their original wooden surrounds with a painted sign.
Cartridges were passed out through an issuing hatch which may have had a sliding door associated with it. The locations of the metal supports for the original oak baton (6 inches by 3 inches) shelving along the back wall of the shell store can still be seen. This shelving was 3 feet above the floor and 3 feet wide. The front wall of the shell store has 7 windows and a door opening to the outside.
The outside wall is 3 feet thick at the base. The door aperture is 3 feet 6 inches wide and the door is 6 feet 6 inches high. The double door may be original. The windows are 4 feet wide and the windows were 4 feet 2 inches, and from original plans were casements. The existing windows are not original.
A grey painted marking ASL is on the floor of the cartridge store; its purpose is not known. The magazine is divided into two parts. The cartridge store at the back, protected by the greatest depth of rock, with the shell store at the front. The cartridge store is 60 feet long, the walls separating it from the shell store are 3 feet thick, the shell store is 9 feet wide and about 80 feet long. The ceilings of both stores are barrel vaulted and built of brick with maximum height of 8 feet 6 inches. The height at walls is 6 feet 6 inches. The wall between the shell store and cartridge store has 4 lamp recesses for lighting the cartridge store. 
The shell store and cartridge stores are connected by a shiffting (sic) lobby, which originally had doors at each end. The wooden doors at the cartridge store end are still in place complete with original markings. The lobby has a row of wooden pegs. The magazine was ventilated by a Howarths Ventilation system (WO 78/5058 part 2) the pipes outside are still in place but the cowlings are missing. The exit holes for the ventilation system in the magazine ceiling are still visible
The shell and cartridge lifts are at the far ends of the shell store. Each emplacement had its own shell and cartridge lifts. The shell lift's original lifting mechanism has been removed. The photograph shows the handcranking mechanism of the type removed. The indents in the masonry where the mechanism was still exist. 
The wooden guides are still in place; they are about 18 feet long and rise about 15 feet. The cartridge lifts are four feet wide and situated in the back wall. The entrance to the lift is supported by a 3 inch by 3 inch girder. The cartridge lift ascends vertically about 10 feet to the gun emplacement. The cartridge lifts still have their original wooden surrounds with a painted sign.
Cartridges were passed out through an issuing hatch which may have had a sliding door associated with it. The locations of the metal supports for the original oak baton (6 inches by 3 inches) shelving along the back wall of the shell store can still be seen. This shelving was 3 feet above the floor and 3 feet wide. The front wall of the shell store has 7 windows and a door opening to the outside.
The outside wall is 3 feet thick at the base. The door aperture is 3 feet 6 inches wide and the door is 6 feet 6 inches high. The double door may be original. The windows are 4 feet wide and the windows were 4 feet 2 inches, and from original plans were casements. The existing windows are not original.