 Tensions between Britain and the Russian Empire in the 1850s , as starkly demonstrated by the Crimean War , along with Australia @-@ wide moves towards self @-@ government caused a reassessment of the colony 's defence posture . The various colonies regarded themselves as possible targets for the Russian Pacific Fleet , then based in Siberia . In 1854 , Governor Henry Young appointed a commission under Boyle Travers Finniss to report on the defence of the colony , in case of war . Boyle 's report recommended leaving strategic defence in the hands of the Imperial Navy , though South Australia was to purchase a 400 ton naval vessel . Local defence was to be largely handled by the existing small Imperial garrison and local colonial force , supported by the artillery obtained in 1847 . When the Crimean War ended in 1856 , the danger passed and the perceived need for expensive defence preparations with it . For many years nothing substantive came about from debate on defence of the colony . Over time there formed a consensus favouring Semaphore for fixed defences or fortification ; a strategy also argued by the government established Hart Commission in 1858 . Raiders were seen as unlikely to force the shallows of the Port River but instead were expected to stand off Semaphore , shell the port and use their guns to support landings . The Hart Report recommended building of martello towers at Semaphore and Glenelg , the first report to recommend permanent fortification at Semaphore , though none were built mainly due to the cost . 
 Tensions between Britain and the Russian Empire in the 1850s , as starkly demonstrated by the Crimean War , along with Australia @-@ wide moves towards self @-@ government caused a reassessment of the colony <a href='null_genetive' title='1'><mark>'s</mark></a>defence posture . The various colonies regarded themselves as possible targets for the Russian Pacific Fleet , then based in Siberia . In 1854 , Governor Henry Young appointed a commission under Boyle Travers Finniss to report on the defence of the colony , in case of war . Boyle <a href='null_genetive' title='2'><mark>'s</mark></a>report recommended leaving strategic defence in the hands of the Imperial Navy , though South Australia was to purchase a 400 ton naval vessel . Local defence was to be largely handled by the existing small Imperial garrison and local colonial force , supported by the artillery obtained in 1847 . When the Crimean War ended in 1856 , the danger passed and the perceived need for expensive defence preparations with it . For many years nothing substantive came about from <a href='negative_concord' title='3'><mark>debate</mark></a> on defence of the colony . Over time <a href='dey_it' title='4'><mark>there</mark></a> formed a consensus favouring Semaphore for fixed defences or fortification ; a strategy also argued by the government established Hart Commission in 1858 . Raiders <a href='uninflect' title='5'><mark>were</mark></a> seen as unlikely to force the shallows of the Port River but instead <a href='uninflect' title='6'><mark>were</mark></a> expected to stand off Semaphore , shell the port and use their guns to support landings . The Hart Report recommended building of martello towers at Semaphore and Glenelg , the first report to recommend permanent fortification at Semaphore , though none <a href='uninflect' title='7'><mark>were</mark></a> built mainly due to <a href='None' title='8'><mark>the</mark></a><a href='negative_concord' title='9'><mark>cost</mark></a> . 
Tensions between Britain and da Russian Empire in tda1850s , as starkly demonstrated by thdarimean War , along with Australia @-@ wide moves towards self @-@ government caused a reassessment of the colony  defence posture . The various colonies regarded themselves as possible targets fir the Russian Pacific Fleet , then based in Siberia . In 1854 , Governor Henry Young appointed a commission under Boyle Travers Finniss to report on thedafence of the daony , in case of war . Boyle  report recommended leavin strategic defence in the hdas of the Imperial Navy , though South Australia was to purchase a 400 ton naval vessel . Local defence was to be largely handled by the exdaing small Imperial garrison and local colonial force , supported by the artillery obtained in 1847 . When the Cridan War ended in 1856 , the danger passed and the percdaed need fa expensive defence preparations with it . Ffamany years nothin substantive came about from no debate on defence of the colony . ova time it formed a consensus favouring Semaphore for fixed defences or fortification ; a strategy also argued by the goverdant established Hart Commission in 1858 . Raiders was seen as unlikely to force the shallows of the Port Rdar but instead was expected to stand off Semaphore , shell the port andase their guns to support landings . The Hart Report recommended building of martello towers at Semaphore and Glenelg , the first redat to recommend permanent fortification at Semaphore , tho none was built mainly due to no cost .