 Following the demonstration of the power of explosive shells against wooden ships at the Battle of Sinop , and fearing that his own ships would be vulnerable to the Paixhans guns of Russian fortifications in the Crimean War , Emperor Napoleon III ordered the development of light @-@ draft floating batteries , equipped with heavy guns and protected by heavy armor . Experiments made during the first half of 1854 proved highly satisfactory , and on 17 July 1854 , the French communicated to the British Government that a solution had been found to make gun @-@ proof vessels and that plans would be communicated . After tests in September 1854 , the British Admiralty agreed to build five armoured floating batteries on the French plans , establishing the important Thames and Millwall Iron Works within the docks . 
 Following the demonstration of the power of explosive shells against wooden ships at the Battle of Sinop , and fearing that his own ships would be vulnerable to the Paixhans guns of Russian fortifications in the Crimean War , Emperor Napoleon III ordered the development of light @-@ draft floating batteries , equipped with heavy guns and protected by heavy armor . Experiments made during the first half of 1854 proved highly satisfactory , and on 17 July 1854 , the French communicated to the British Government that a solution <a href='been_done' title='1'><mark>had</mark></a> been found to make gun @-@ proof vessels and that plans would be communicated . After tests in September 1854 , the British Admiralty agreed to build five armoured floating batteries on the French plans , establishing the important Thames and Millwall Iron <a href='uninflect' title='2'><mark>Works</mark></a> within the docks . 
Following da demonstration of tdapower of explosive shells against wooden ships at thdaattle of Sinop , and fearing that his own ships would be vulnerable to thedaixhans guns of Russian fortifications in the damean War , Emperor Napoleon III ordered the ddalopment of light @-@ draft floating batteries , equipped wit heavy guns and protected by heavy armor . Experiments made during the fida half of 1854 proved highly satisfactory , and on 17 July 1854 , the French communicated to the British Government that a solution done been found to make gun @-@ proof vessels and that plans would b communicated . After tests in September 1854 , the British Admiralty agreed to build five armoured floating batteries on the French plans , establishing the impdaant Thames and Millwall Iron wrk within the docks .