 Prior to 1895 two 6 @-@ inch ( 200 mm ) breech @-@ loading guns had been imported for use in small boats . This use was rejected by military authorities and the guns sat unused . In 1895 the South Australian Defence Committee proposed that the guns be mounted at Fort Glanville , replacing the 64 @-@ pounders whose siege carriages were then unfit for service . This proposal would have greatly extended the useful life of the fort , at little cost . The two military branches , army and navy , could not reach agreement and the proposal was abandoned by 1897 . The gun 's eventual fate is unknown , though a gun found in the Port River later indicates they may have been dumped . 
