 Gun emplacements were made , about a mile apart south of the fort , for six 16 @-@ pounder field guns to provide close defence in case of an attempted beach landing . From 1890 the fort was equipped with <unk> armament . It received an 1867 Whitworth 12 @-@ pounder RML field gun and a 5 @-@ barrel 0 @.@ 45 " <unk> @-@ <unk> cartridge firing <unk> gun . The 12 @-@ pounder had fired 222 effective full charges by 1902 ; at which time both weapons were obsolete and their eventual fate is unknown . A 32 @-@ pounder 56 long cwt ( 2 @,@ 800 kg ) smoothbore gun on a stepped wooden carriage was purchased in 1878 . Manufactured by the Royal Arsenal in 1806 , it was the familiar " ships cannon " and came to South Australia with two other identical guns . By 1902 no ammunition was held for it and it was listed as for instruction only . The gun was probably destroyed in the 1930s — certainly by the end of the 1940s — with pieces of such a gun found on site in 1983 . 
