The Brazilian ironclad ''Rio de Janeiro'' was an armored gunboat ( pt, Canhoneira Couraçada Nr. 3) built for the

Brazilian Navy ) , colors= Blue and white , colors_label= Colors , march= "Cisne Branco" ( en, "White Swan") (same name as training ship ''Cisne Branco'' , mascot= , equipment= 1 multipurpose aircraft carrier7 submarines6 frigates2 corvettes4 amphibious warf ...

during the Paraguayan War in the mid-1860s. Like the other two gunboats she was built in Brazil and was designed as a

casemate ironclad The casemate ironclad was a type of iron or iron-armored gunboat briefly used in the American Civil War by both the Confederate States Navy and the Union Navy. Unlike a monitor-type ironclad which carried its armament encased in a separate a ...

. Commissioned in April 1866, the ship did not enter combat until September, when she bombarded Paraguayan fortifications at Curuzu. ''Rio de Janeiro'' hit two mines on 2 September and rapidly sank, taking 53 of her crew with her.

Design and description

''Rio de Janeiro'' was designed to meet the need of the Brazilian Navy for a small, simple, shallow-draft armored gunboat capable of withstanding heavy fire. A

design was chosen for ease of construction and a bronze ram, long, was fitted. The hull was sheathed with Muntz metal to reduce

biofouling Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...

. For sea passages the ship's freeboard could be increased to by use of removable bulwarks high. On riverine operations, the bulwarks and the ship's masts, were usually removed.Gratz, p. 144 The ship measured

long overall __NOTOC__ Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and ...

, with a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

of and had a mean draft of . ''Rio de Janeiro'' normally displaced and at

deep load The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into wei ...

. Her crew numbered 148 officers and men.

Propulsion

''Rio de Janeiro'' had a single

John Penn & Sons John Penn and Sons was an English engineering company based in London, and mainly known for its marine steam engines. History Establishment In 1799, engineer and millwright John Penn (born in Taunton, Somerset, 1770; died 6 June 1843) started ...

2-cylinder

steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...

driving a single 2-bladed propeller. Her engine was powered by two tubular

boiler A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central h ...

s. The engine produced a total of which gave the ship a maximum speed of . The ship's funnel was mounted directly in front of her casemate. ''Rio de Janeiro'' carried enough coal for six days' steaming.

Armament

''Rio de Janeiro'' mounted two 70-pounder Whitworth rifled muzzle loaders and two

68-pounder The 68-pounder cannon was an artillery piece designed and used by the British Armed Forces in the mid-19th century. The cannon was a smoothbore muzzle-loading gun manufactured in several weights, the most common being , and fired projectiles of ...

smoothbore guns in her

casemate A casemate is a fortified gun emplacement or armored structure from which artillery, guns are fired, in a fortification, warship, or armoured fighting vehicle.Webster's New Collegiate Dictionary When referring to Ancient history, antiquity, th ...

. To minimize the possibility of shells or splinters entering the casemate through the gunports they were as small as possible, allowing only a 24°-arc of fire for each gun. The rectangular, casemate had two gun ports on each side as well as the front and rear.Gratz, p. 147 The 70-pounder gun weighed and fired a shell that weighed .Holley, p. 34 The gun had a maximum range of . The solid shot of the 68-pounder gun weighed approximately while the gun itself weighed . The gun had a range of at an elevation of 12°. All of the guns could fire both solid shot and explosive shells.

Armor

The hull of ''Rio de Janeiro'' was made from three layers of wood, each thick. The ship had a complete

wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a ...

waterline

belt Belt may refer to: Apparel * Belt (clothing), a leather or fabric band worn around the waist * Championship belt, a type of trophy used primarily in combat sports * Colored belts, such as a black belt or red belt, worn by martial arts practition ...

, high. It had a maximum thickness of covering the machinery and

magazine A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...

s, elsewhere. The curved deck, as well as the roof of the casemate, was armored with of wrought iron. The casemate was protected by 102 millimeters of armor on all four sides, backed by of wood capped with a 102 mm layer of peroba hardwood.

Service

''Rio de Janeiro'' was laid down at the Arsenal de Marinha da Corte in

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

on 28 June 1865, during the Paraguayan War, which saw Argentina, Brazil and Uruguay allied against

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

. She was launched on 18 February 1866 and completed on 1 March 1866. Commissioned in April she reached the combat zone on 4 May. The ship reached Corrientes, with the ironclad , in July 1866. On 1 September ''Rio de Janeiro'' bombarded the Paraguayan fortifications at Curuzú in company with the other Brazilian ironclads. A 68-pounder shell entered one of her gunports during the bombardment, killing four men and wounding five. The next day, after her damage was repaired, the ship struck two floating mines ( 'torpedoes') in the

River Paraguay The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

while trying to rendezvous with the other Brazilian ironclads bombarding Curupayty.Gratz, p. 150. Gratz says the

Apa River The Apa River (Spanish: Río Apa, Portuguese: Rio Apa) is a river of Paraguay and Brazil. It is a tributary of the Paraguay River, which in turn is a tributary of the Paraná River. It starts in the Amambai Mountains of the Brazilian state of Ma ...

but this is a mistake since it lay many hundreds of miles north of the combat zone. ''Rio de Janeiro'' sank instantly with the loss of 53 of her crew.Meister, p. 12 She remains there, entombed under some of sand.

Footnotes

References

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External links

Brief history of ''Rio de Janeiro''
{{DEFAULTSORT:Rio de Janeiro Ships built in Brazil Gunboats of the Brazilian Navy Ironclad warships of the Brazilian Navy Maritime incidents in September 1866 Ships sunk by mines 1866 ships Riverine warfare