Triple Alliance War: Riachuelo, the Greatest Naval Battle in America

Riachuelo

On June 11, 1865, the largest naval battle in America was fought, at the site where the water course called Riachuelo flows, located at the mouth of the Paraná River at its conjunction with the Paraguay River, a few kilometers from the city of Corrientes, over Argentine waters. That area of the province of Corrientes was at that time in the power of Paraguayan troops, so they had control of the coast.

By early 1865, Solano López was determined to take control of the Paraná River in the first place to control an entire future cleansing of the Río de la Plata. If he were successful in sneaking up on the Brazilian imperial fleet in the lower waters of the river then he would achieve an important victory that would enable deeper land operations in the future.

Surprise would be essential. At the end of 1864 the Paraguayan navy consisted of 17 small vessels of various sizes. Only two of them, Anhambay and Tacuarí, were built as gunboats. During the 1860s López was hoping to get new ironclads added to his fleet. He maintained contacts with some European countries to obtain these ships. This project, however, had to be abandoned due to financial problems.

The imperial fleet, on the other hand, fielded 45 vessels, 33 steamships and 12 sailing ships at the beginning of the war. The force had at its disposal a total manpower of almost 2,400 officers and men. The main units were the Niterói propeller type and the Amazonas rear-bladed propeller boat. The fleet, however, had a major defect: it had been designed for the high seas rather than for river operations.



On June 8, the Paraguayan fleet was concentrated in Asunción for the departure towards the fortress of Humaitá. López himself was aboard the Tacuarí. The entire population of the capital was present to witness the departure. At the end of the morning the ships left for the fortress. As soon as he arrived in Humaitá on the morning of the next day, López immediately began to prepare the attack against the enemy squadron located near Corrientes, in a width called Riachuelo, which gave support to the land forces of the Triple Alliance to expel the Paraguayans of Corrientes. He gathered the bulk of the Paraguayan armada to hit the Brazilian ships at dawn on June 11. The squadron consisted of eight ships, the flagship Tacuarí, the recently arrived Paraguarí, built in England, the captured Brazilian steamship Marquês de Olinda and the Ygureí, Ybera, Yporá, Jejuí, Salto Oriental and the Pirabebé. Along with the ships, six low flat-bottomed barges with an eight-inch gun each, known as flatboats, would be towed to confront the enemy. The squadron numbered 36 guns. Commodore Pedro Ignacio Meza would order the assault. In addition, the Paraguayan ships would have the support of a cannon battery under the command of Colonel José Maria Bruguez placed along the river coastline.

The Brazilian squadron anchored near Corrientes formed the Amazonas (flagship) and the ships Jequitinhonha, Belmonte, Parnaíba, Ipiranga, Mearin, Iguatemi, Araguarí and the Beberibé. The total firepower of the squadron amounted to 59 guns. Admiral Francisco Manuel Barroso was in command of the ships.

Meza must sail downstream of the Paraná during dawn on June 11 to reach the enemy around dawn. The surprise would compensate for the fact that the Paraguayan ships were outgunned. At two in the morning the fleet left Humaitá. At five o'clock the chatas assembled the ships. Despite this, a problem with the Iberá's engine delayed the plan.

Battle Plan


Only at nine o'clock, in the broad light of day, the ships reached Riachuelo.

After placing the chatas near the coast, Meza led his ships directly into the enemy to split the Imperial squadron in two.

Barroso's ships were anchored near the confluence of the Paraná and two narrow channels. The attack, if not entirely a surprise, occurred when Barroso's ships were lined up toward the coast.

Meza's squadron passed over the enemy ships sending fire on them. Each of his ships chooses a ship to pawn. Soon the Amazonas was under fire from the Tacuarí, while the Ipiranga exchanged fire with the Salto.

Google Map of the battle zone

In the battle the two squadrons changed positions. Meza was below the squadron and cut off by the enemies from his base in Humaitá. The Paraguayan commander then adopted the strategy of luring the enemies into the lower channels where they would not be able to maneuver as well as the Paraguayans did.

The Jequitinhonha, Barroso's largest ship after the Amazon, was struck on a sandbank. This made him an easy target for Bruguez's ruthless artillery.

The Belmonte was hit several times by the chatas' fire.

The Parnaíba hit the coast and was set adrift. Several Paraguayan ships soon surrounded her. The Marquês de Olinda boarded the Brazilian ship and a deadly combat occurred on the deck of Parnaíba. On several occasions, the Paraguayans tried to take command of the ship. Only with the iron resistance of the Parnaíba crew did he save the ship. Finally, a final assault was expelled and the ship slid away from the enemy.

At this point, things began to change.

Despite the difficulties in maneuvering, the superior firepower of Barroso's ships began to show effectiveness. The Jejuí was sunk by nearby fire from Brazilian ships. The Marquês de Olinda caused her boilers to explode and she was out of action. The Paraguarí was hit by the Amazon and was left helpless. Meza gave orders to retreat. At 1 P.M. the combat was over. Of the eight Paraguayan vessels, only four returned to Humaitá. The others were sunk, captured or left stranded on a sandbank (this included the Paraguarí, the Jejuí, the Marquês de Olinda and the Salto Oriental). Two flatboats were sunk and the other four remained in Brazilian hands. A few days later, however, the Paraguayans succeeded in removing the Paraguarí, sending the ship to Asunción for repairs. The Paraguayan casualties are not known exactly. Brazilian assumptions of 1,000 casualties are probably exaggerated. Perhaps this number is between 300 and 400 (Brazilian sources say it can reach 750).

Meza died a few days later in Humaitá from the wounds he received during the battle.

The imperial squadron lost one ship, the Jequitinhonha while two other vessels, the Parnaíba and Belmonte were severely damaged. The Ipiranga was slightly damaged. Barroso had 104 men killed, 123 wounded and 20 lost.

The Paraguayans failed in the attempt to have the entire power of the Paraná River from Asunción to Montevideo. Furthermore, they would not be able to replace the lost ships. While Brazil added new units to the fleet.




Remarks

• I would highlight the fact that in the river the East-West escape and maneuver axes are considerably smaller. For this reason and due to the number of ships used, the battle had to have a lot of congestion between so many ships and ships giving back to the cannon shots. Another issue was the loss of surprise of the attack given that the Iberá broke down. This caused the attack to begin at 9 AM when it was planned for 5 AM. It was a failure of surprise that added light to the scenario to the detriment of the Paraguayan plan. As in Tuyuty, the loss of surprise caused a good initial attack plan to falter. (SiberianSky, FDRA moderator).
• "...largest naval battle in America"... The most paradoxical thing is that this action was in a river (Mongoose, FDRA moderator).