Bahia - class cruiser The " Bahia " class was a pair of scout cruiser s built for Brazil by Armstrong Whitworth in the United Kingdom , based on a design that borrowed heavily from the British scout cruiser s . The class comprised the lead ship and her sister , along with a canceled third ship , " Ceara " . Both were named after states of Brazil . As a class , they were the fastest cruisers in the world when commissioned , and the first in the Brazilian Navy to use steam turbines for propulsion . In the mid - 1920s , both ships were extensively modernized with three new Brown – Curtis turbine engines and six new Thornycroft boilers , and , in the process , was converted from coal - burning ships to oil - burning . The refit resulted in a striking aesthetic change , with the exhaust being trunked into three funnels , instead of two . The armament was also modified ; three Madsen guns , a Hotchkiss machine gun , and four torpedo tubes were added . In the Second World War , both were used as convoy escorts . On 4 July 1945 , the " Bahia " was lost after an accident caused a massive explosion which incapacitated the ship and sunk her within minutes , resulting a large loss of life . The " Rio Grande do Sul " survived the war and was scrapped in 1948 . Design . The class ' s design borrowed heavily from the British scout cruiser s . The ships displaced , and their dimensions were overall , between perpendiculars , at the beam , and a draft of forward , amidships , and aft . They were powered by five Parsons steam turbines , and ten Yarrow boilers , with a coal bunker that could hold a normal load of , and a maximum load of . The " Bahia " class was designed to reach a speed of ; both ships exceeded this during trials with the " Bahia " reaching at trial . As designed , the class ' s range was at , or at . The class was armed with ten / 50 caliber , six QF 3 pounder / 50 caliber guns and two torpedo tube s . The class was lightly armored with only of deck armor , with the conning tower having . Construction . The class was part of a large 1904 naval building program by Brazil . Also planned as part of this were the two dreadnought s , ten s , three submarine s and a submarine tender . With a design that borrowed heavily from the British scout cruisers , " Bahia " s keel was laid first on 19 August 1907 in Armstrong Whitworth ' s Elswick , Newcastle upon Tyne yard , followed by " Rio Grande do Sul " 30 August 1907 . Construction took about a year and a half , and both ships were launched in 1909 . Both ships were completed and commissioned into the navy in 1910 . As a class , " Bahia " and " Rio Grande do Sul " were the fastest cruisers in the world when they were commissioned , and the first in the Brazilian Navy to utilize steam turbines for propulsion . Modernization . In the mid - 1920s , the class underwent significant modernization . The original five turbines were replaced by three Brown – Curtiss turbines , while the original ten boilers were replaced by six Thornycroft oil - burning boilers , which necessitated the addition of a third funnel . The former coal bunkers , along with some of the space freed up by the decrease in boilers , were converted to hold of oil . These changes resulted in " Bahia " s top speed increasing to . All of the boats onboard were replaced , and three Madsen guns , a Hotchkiss machine gun , and four torpedo tubes were added to give the ship a defense against aircraft and more power against surface ships . The class was modernized again twice during World War II , in both 1942 and 1944 . The modernizations were not as extensively as it was in the 1920s ; the Brazilian Navy ' s official history of the " Bahia " reports these but does not specify what modifications the ship underwent in which year . Two guns were replaced with L / 23 AA guns , Madsen guns were replaced with seven Oerlikon 20 mm cannon s in single mounts , and a director for these guns was installed . Two depth charge tracks were added , improved range - finders were added to the guns , and sonar and radar were fitted , in addition to other minor modifications . Loss of the Bahia . On 4 July 1945 , " Bahia " was acting as a plane guard for transport aircraft flying from the Atlantic to Pacific theaters of war . While " Bahia " s gunners were firing at a kite for anti - aircraft practice , one fired too low and hit depth charge s stored near the stern of the ship . A massive explosion incapacitated the ship and sunk her within minutes , resulting a large loss of life .