Brazilian ironclad Sete de Setembro The Brazilian ironclad " Sete de Setembro " was an wooden - hulled armored frigate built for the Brazilian Navy during the Paraguayan War in the late 1860s . Construction was delayed by a debate over her armament and she was not completed until 1874 , by which time the ship was essentially obsolete . " Sete de Setembro " was transferred to Rio de Janeiro in the 1880s and captured by the rebels during the Fleet Revolt of 1893 – 94 . She sank after she caught fire when the government forces recaptured her in late 1893 . Design and description . " Sete de Setembro " was designed as an enlarged , and seaworthy , version of the casemate ironclad as part of the 1867 Naval Program , but she was ultimately classified as an armored frigate . Before construction began weather decks were added fore and aft to improve seaworthiness and protect the capstan s fore and aft . The hull was sheathed with Muntz metal to reduce biofouling and a bronze ram , long , was fitted . For sea passages the ship ' s freeboard could be increased to by use of removable bulwarks high . The ship measured long overall , with a beam of and she had a mean draft of . " Sete de Setembro " normally displaced . Her crew numbered 185 officers and men . Propulsion . " Sete de Setembro " had two John Penn & Sons 2 - cylinder steam engines , each of which drove a single propeller . They were powered by four rectangular boilers that produced a total of which gave the ship a maximum speed of . The ship ' s funnel was mounted in the middle of her casemate and she carried a maximum of of coal . Armament . Two choices were debated for the ship ' s armament . The first was for six muzzle - loading 150 - pounder Whitworth guns mounted in a central casemate with the end guns pivoting to fire either fore or aft . The second option was for two gun turrets , each mounting a pair of 300 - pounder Whitworth guns . A compromise was reached with a casemate armed with four 300 - pounder Whitworth guns on pivot mounts at the corners . A new controversy arose , however , over the choice of Whitworth guns as the navy preferred Armstrong weapons . A decision in favor of the Whitworth guns was finally made after a debate of several years , which delayed the completion of the ship . The solid shot of the Whitworth gun weighed approximately while the gun itself weighed . Armor . " Sete de Setembro " had a complete wrought iron waterline belt that was high and had a maximum thickness of . The ship ' s deck and the roof of the casemate was protected with of wrought iron . The casemate was armored identically as the hull and both were backed by of wood . Service . " Sete de Setembro " was laid down at the Arsenal de Marinha da Côrte in Rio de Janeiro on 8 January 1868 , during the late stages of the Paraguayan War ( also known as the War of the Triple Alliance ) , which saw Argentina and Brazil allied against Paraguay . She was launched on 16 May 1874 , after lengthy delays as to her armament , and commissioned on 4 July 1874 by which time she was obsolete . She was briefly placed into reserve between August 1876 and June 1877 . The ship was stationed in Montevideo during the early 1880s before she was transferred to Rio de Janeiro in 1884 . " Sete de Setembro " was assigned to the Evolution Squadron in November 1885 despite having been reclassified in 1879 as a floating battery by virtue of her weak armor and lack of compartmentalization . By 1893 , however , her engines had been removed and she was captured by the rebels during the Fleet Revolt of 1893 – 94 . They had her towed to a position near Armação Beach to be used as a stationary guard post . The ship was recaptured on 16 December 1893 , but she sank after catching fire .