 The era of the wooden steam ship @-@ of @-@ the @-@ line was brief , because of new , more powerful naval guns . In the 1820s and 1830s , warships began to mount increasingly heavy guns , replacing 18- and 24 @-@ pounder guns with 32 @-@ pounders on sailing ships @-@ of @-@ the @-@ line and introducing 68 @-@ pounders on <unk> . Then , the first shell guns firing explosive shells were introduced following their development by the French <unk> Henri @-@ Joseph <unk> , and by the 1840s were part of the standard armament for naval powers including the French Navy , Royal Navy , Imperial Russian Navy and United States Navy . It is often held that the power of explosive shells to smash wooden hulls , as demonstrated by the Russian destruction of an Ottoman squadron at the Battle of <unk> , spelled the end of the wooden @-@ <unk> warship . The more practical threat to wooden ships was from conventional cannon firing red @-@ hot shot , which could <unk> in the hull of a wooden ship and cause a fire or ammunition explosion . Some navies even experimented with hollow shot filled with molten metal for extra incendiary power . 
