The Magazine has thick stone walls, and its roof is protected by an earth covering which together were designed to withstand the effects of enemy fire. The Magazine held 200 Shells and 200 Propellant Cartridges. A narrow passageway runs round the magazine. This was used by men serving ammunition to the guns.
In 1885, during an upgrade of the fort, it was recommended, “As these guns bear only on inner waters 100 rounds per gun will suffice, and for this amount accommodation exists. It appears that the remainder can be stored in Blakang Mati East (Fort Connaught)”.
Soldiers entering the Magazine had to remove their footwear and strip to their underclothes before donning special clothing and footwear for working within the magazine. Soldiers working in the Magazine had to take special precautions to prevent any chance of setting off an explosion. Items such as Lucifers (matches), smoking materials and inflammable items were not permitted past the entrance. Any soldier disobeying magazine regulations would find themselves facing very severe punishment..
Magazine clothes and footwear were not allowed to be worn outside the magazine. This was particularly important for footwear, as any grit or small stones on the soled could trigger a spark.
Men involved in the transfer of propellant charges to the guns would not enter the Magazine itself. They would work in the passageway, receiving cartridges passed through the ammunition hatches. This reduced the risk of a catastrophic explosion should an accident occur. Shells were too heavy to lift through hatches, and would have been passed out of the door onto trolleys in the passageway between the guns and the Magazine.