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 armored floating batteries on the French plans, establishing the important Thames and Millwall Iron Works within the docks.