Bahia class cruiser
Encyclopedia
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 , along with her sister ship
. 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 turbine
s 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 20.1 mm (0.791338582677166 in) Madsen guns, a 7 mm (0.275590551181102 in) Hotchkiss
machine gun, and four 533 mm (21 in) 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.
s. The ships displaced 3100 tonnes (3,051 LT), and their dimensions were 122.38 metre overall, 115.82 metre between perpendiculars, 11.89 – at the beam, and a draft of 3.81 metre forward, 4.75 metre amidships, and 4.42 metre aft. They were powered by five Parsons
steam turbine
s, and ten Yarrow boilers, with a coal bunker that could hold a normal load of 150 t (147.6 LT), and a maximum load of 650 t (639.7 LT).
The Bahia class was designed to reach a speed of 26.5 knots (51.9 km/h); both ships exceeded this during trials with the Bahia reaching 27.016 knots (52.9 km/h) at trial. As designed, the class's range was 1400 nmi (2,592.8 km; 1,611.1 mi) at 23.5 knots (46.1 km/h), or 3500 nautical miles (6,482 km) at 10 knots (19.6 km/h). The class was armed with ten 120 mm (4.7 in)/50 caliber, six QF 3 pounder 47 mm (1.9 in)/50 caliber guns
and two 457 mm (18 in) torpedo tube
s. The class was lightly armored with only 19 mm (0.748031496062992 in) of deck armor, with the conning tower
having 76 mm (3 in).
s, ten s, three submarine
s and a submarine tender
. With a design that borrowed heavily from the British scout cruisers, Bahias 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.The Miramar Ship Index—using information from contemporary builders' records—and Poder Naval Online record Bahias launching date as 20 January 1909, and her sister ship Rio Grande do Suls as 20 April 1909. Conway's All the World's Fighting Ships 1906–1921 and the Brazilian Navy's official history reverse these dates, giving 20 January for Rio Grande do Sul and 20 April for Bahia. This article uses the former date because of Miramars use of builders' records, which, in this case, should be the most accurate source. See: ; ; Gardiner and Gray eds. (1984), p. 405; 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 turbine
s for propulsion.
machine gun, and four 533 mm (21 in) 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 47 mm (1.9 in)
guns were replaced with 76 mm (3 in) 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 120 mm (4.7 in) guns, and sonar and radar were fitted, in addition to other minor modifications.Regarding the installation of sonar, it is not clear whether it was fitted for the first time in 1942 (and used in the 10 July depth charging) or whether a more modern sonar replaced an outmoded version in either 1942 or 1944.
flying from the Atlantic to Pacific theaters of war. While Bahias 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.
Ship class
A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....
of scout cruiser
Scout cruiser
A scout cruiser was a type of warship of the early 20th Century, which were smaller, faster, more lightly armed and armoured than protected cruisers or light cruisers, but larger than contemporary destroyers...
s built for Brazil by Armstrong Whitworth
Armstrong Whitworth
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. Headquartered in Elswick, Newcastle upon Tyne, Armstrong Whitworth engaged in the construction of armaments, ships, locomotives, automobiles, and aircraft.-History:In 1847,...
in the United Kingdom, based on a design that borrowed heavily from the British scout cruiser
Scout cruiser
A scout cruiser was a type of warship of the early 20th Century, which were smaller, faster, more lightly armed and armoured than protected cruisers or light cruisers, but larger than contemporary destroyers...
s. The class comprised the lead ship , along with her sister ship
Sister ship
A sister ship is a ship of the same class as, or of virtually identical design to, another ship. Such vessels share a near-identical hull and superstructure layout, similar displacement, and roughly comparable features and equipment...
. 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 turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s for propulsion.
In the mid-1920s, both ships were extensively modernized with three new Brown–Curtis
John Brown & Company
John Brown and Company of Clydebank was a pre-eminent Scottish marine engineering and shipbuilding firm, responsible for building many notable and world-famous ships, such as the , the , the , the , the , and the...
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 20.1 mm (0.791338582677166 in) Madsen guns, a 7 mm (0.275590551181102 in) Hotchkiss
Hotchkiss et Cie
Société Anonyme des Anciens Etablissements Hotchkiss et Cie was a French arms and car company established by United States engineer Benjamin B. Hotchkiss, who was born in Watertown, Connecticut. He moved to France and set up a factory, first at Viviez near Rodez in 1867, then at Saint-Denis near...
machine gun, and four 533 mm (21 in) 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' design borrowed heavily from the British scout cruiserScout cruiser
A scout cruiser was a type of warship of the early 20th Century, which were smaller, faster, more lightly armed and armoured than protected cruisers or light cruisers, but larger than contemporary destroyers...
s. The ships displaced 3100 tonnes (3,051 LT), and their dimensions were 122.38 metre overall, 115.82 metre between perpendiculars, 11.89 – at the beam, and a draft of 3.81 metre forward, 4.75 metre amidships, and 4.42 metre aft. They were powered by five Parsons
Parsons Marine Steam Turbine Company
Parsons Marine Steam Turbine Company was a British engineering company based in Wallsend, North England, on the River Tyne.-History:The company was founded by Charles Algernon Parsons in 1897 with £500,000 of capital, and specialised in building the steam turbine engines that he had invented for...
steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s, and ten Yarrow boilers, with a coal bunker that could hold a normal load of 150 t (147.6 LT), and a maximum load of 650 t (639.7 LT).
The Bahia class was designed to reach a speed of 26.5 knots (51.9 km/h); both ships exceeded this during trials with the Bahia reaching 27.016 knots (52.9 km/h) at trial. As designed, the class's range was 1400 nmi (2,592.8 km; 1,611.1 mi) at 23.5 knots (46.1 km/h), or 3500 nautical miles (6,482 km) at 10 knots (19.6 km/h). The class was armed with ten 120 mm (4.7 in)/50 caliber, six QF 3 pounder 47 mm (1.9 in)/50 caliber guns
QF 3 pounder Hotchkiss
The QF 3 pounder Hotchkiss was a light 47-mm naval gun introduced in 1886 to defend against new small fast vessels such as torpedo boats, and later submarines...
and two 457 mm (18 in) torpedo tube
Torpedo tube
A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels...
s. The class was lightly armored with only 19 mm (0.748031496062992 in) of deck armor, with the conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....
having 76 mm (3 in).
Construction
The class was part of a large 1904 naval building program by Brazil. Also planned as part of this were the two dreadnoughtDreadnought
The dreadnought was the predominant type of 20th-century battleship. The first of the kind, the Royal Navy's had such an impact when launched in 1906 that similar battleships built after her were referred to as "dreadnoughts", and earlier battleships became known as pre-dreadnoughts...
s, ten s, three submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s and a submarine tender
Submarine tender
A submarine tender is a type of ship that supplies and supports submarines.Submarines are small compared to most oceangoing vessels, and generally do not have the ability to carry large amounts of food, fuel, torpedoes, and other supplies, nor to carry a full array of maintenance equipment and...
. With a design that borrowed heavily from the British scout cruisers, Bahias keel
Keel
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...
was laid first on 19 August 1907 in Armstrong Whitworth's
Armstrong Whitworth
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. Headquartered in Elswick, Newcastle upon Tyne, Armstrong Whitworth engaged in the construction of armaments, ships, locomotives, automobiles, and aircraft.-History:In 1847,...
Elswick, Newcastle upon Tyne yard
Newcastle upon Tyne
Newcastle upon Tyne is a city and metropolitan borough of Tyne and Wear, in North East England. Historically a part of Northumberland, it is situated on the north bank of the River Tyne...
, followed by Rio Grande do Sul 30 August 1907. Construction took about a year and a half, and both ships were launched
Ship naming and launching
The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...
in 1909.The Miramar Ship Index—using information from contemporary builders' records—and Poder Naval Online record Bahias launching date as 20 January 1909, and her sister ship Rio Grande do Suls as 20 April 1909. Conway's All the World's Fighting Ships 1906–1921 and the Brazilian Navy's official history reverse these dates, giving 20 January for Rio Grande do Sul and 20 April for Bahia. This article uses the former date because of Miramars use of builders' records, which, in this case, should be the most accurate source. See: ; ; Gardiner and Gray eds. (1984), p. 405; Both ships were completed and commissioned
Ship commissioning
Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...
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 turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s for propulsion.
Modernization
In the mid-1920s,The official history of the ship gives a 1924–1927 range, while Conway's All The World's Fighting Ship's 1906–1921 p. 405 and Poder Naval Online give 1925–1926. 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 588120 l (155,364.9 US gal) of oil. These changes resulted in Bahias top speed increasing to 28 kn (34.1 mph; 54.9 km/h). All of the boats onboard were replaced, and three 20.1 mm (0.791338582677166 in) Madsen guns, a 7 mm (0.275590551181102 in) HotchkissHotchkiss et Cie
Société Anonyme des Anciens Etablissements Hotchkiss et Cie was a French arms and car company established by United States engineer Benjamin B. Hotchkiss, who was born in Watertown, Connecticut. He moved to France and set up a factory, first at Viviez near Rodez in 1867, then at Saint-Denis near...
machine gun, and four 533 mm (21 in) 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
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, 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 47 mm (1.9 in)
QF 3 pounder Hotchkiss
The QF 3 pounder Hotchkiss was a light 47-mm naval gun introduced in 1886 to defend against new small fast vessels such as torpedo boats, and later submarines...
guns were replaced with 76 mm (3 in) L/23 AA guns, Madsen guns were replaced with seven Oerlikon 20 mm cannon
Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original design by Reinhold Becker of Germany, very early in World War I, and widely produced by Oerlikon Contraves and others...
s in single mounts, and a director
Fire-control system
A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more...
for these guns was installed. Two depth charge tracks were added, improved range-finders were added to the 120 mm (4.7 in) guns, and sonar and radar were fitted, in addition to other minor modifications.Regarding the installation of sonar, it is not clear whether it was fitted for the first time in 1942 (and used in the 10 July depth charging) or whether a more modern sonar replaced an outmoded version in either 1942 or 1944.
Loss of the Bahia
On 4 July 1945, Bahia was acting as a plane guard for transport aircraftMilitary transport aircraft
Military transport aircraft are typically fixed and rotary wing cargo aircraft which are used to deliver troops, weapons and other military equipment by a variety of methods to any area of military operations around the surface of the planet, usually outside of the commercial flight routes in...
flying from the Atlantic to Pacific theaters of war. While Bahias gunners were firing at a kite for anti-aircraft practice, one fired too low and hit depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
s stored near the stern
Stern
The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...
of the ship. A massive explosion incapacitated the ship and sunk her within minutes, resulting a large loss of life.