Passage of Humaitá

Passage of Humaitá
Part of the Siege of Humaitá
Brazilian Navy forcing passage through the fortress Humaitá
Date 19 February 1868 Location Paraguay River, Humaitá Result Brazilian victory
Belligerents
Paraguay	Empire of Brazil
Commanders and leaders
Solano López	Delfim de Carvalho
Strength
Fortress of Humaitá	3 ironclads 3 monitors
Casualties and losses
unknown	9 wounded

The Passage of Humaitá (Portuguese: Passagem de Humaitá) was a military operation in which a force of six Brazilian Navy monitors was ordered to dash past the Fortress of Humaitá on the Paraguay River. The event took place on February 19th 1868, during the Paraguayan War. The fortress, by then fully surrounded by forces on both land and water, fell on July 25th 1868.

Historical background

Passage of Humaitá, by Admiral Trajano Augusto de Carvalho.

The Fortress of Humaitá was a defensive system on the River Paraguay that prevented enemy shipping ascending the river and hence invading the Republic of Paraguay or recovering the Brazilian province of Mato Grosso (which lies further up the river, was practically inaccessible except via the river, and had been seized by the forces of the Paraguayan dictator Francisco Solano López).

On August 1st 1867 the Allies commander-in-chief the Argentine General Bartolome Mitre ordered the Brazilian imperial fleet to secure a passage through Curupaiti and Humaitá. On August 15th, two divisions of five battleships passed without incident at Curupaiti, however artillery fire forced them to stop at Humaitá. This news caused conflict in the Allied high command. Under Article 3 of the Treaty of the Triple Alliance the Brazilian naval force was not under the command of Mitre but of the Brazilian Admiral Tamandaré. The Brazilian naval command objected that attacking the fortress from the river would be futile and withdrew their fleet, pending a land-based attack which began on August 18th.

From Tuiu-Cuê, the allies headed north and took the villages of São Solano, Vila do Pilar, and Tayi.^[1] They finally laid siege to Humaitá itself, isolating it from Asunción, except by river.

How the passage of Humaitá was effected

The Brazilian navy possessed a number of monitors and this type of heavily armoured vessel could not readily be sunk by the landward artillery of the day. But the navigation of the river was also blocked by a chain boom which was part of the Humaitá fortification complex. It consisted of a number of chains twisted together slung from bank to bank; in order to proceed, it was necessary for an invading naval force somehow to cut through these chains. Since at this point the channel was exposed to the fire of the Paraguayan batteries, it was no easy task.

Even so, there was an Achilles' heel. According to Lt Colonel George Thompson (engineer) of the Paraguayan army, the total length of the chain was too great for the unsupported catenary to be drawn tight enough: accordingly, it was made to rest on intermediate floating supports. Eventually the Brazilian navy succeeded in sinking all of these supports:

The [Brazilian] ironclads fired for three months at these pontoons and canoes, sinking all of them, when, of course, the chain went to the bottom, as the river there is about 700 yards wide, and the chain could not be drawn tight without intermediate supports. The chain was thus buried some two feet under the mud of the river, offering no obstacle whatever to the navigation.^[2]

On February 19th 1868 when the river was unusually high^[3] Commander Joaquim José Inácio de Barros ordered the force of 6 monitors to pass Humaitá. Since the chain was lying in the river bed and since monitors were practically immune to brief artillery fire, there were few casualties and minimal damage to any of the ships.^[4] Because the Paraguayans could no longer resupply the fortress by river the garrison was starved out and the fortress was captured by the Allied landward forces on 25th July 1868. This was they key event in the Paraguayan War.

Notes

1. Donato.
2. Thompson, 239.
3. Burton, 332.
4. Doratioto, 308-9.

References

• Burton, Captain Sir Richard (1870). Letters From the Battle-Fields of Paraguay. London: Tinsley Brothers.
• Donato, Hernâni. Dicionário das Batalhas Brasileiras. São Paulo, Editora Ibrasa, 1987.
• Doratioto, Francisco (2008). Maldita Guerra. Buenos Aires: Emecé Editores. ISBN 978-950-04-2574-2.
• Thompson, George (1869). The War In Paraguay: With a Historical Sketch of the Country and Its People and Notes Upon the Military Engineering of the War. London: Longman’s, Green and Co. (Note: Not all bound copies of this important source book have a complete set of maps. A scanned version of a good copy at the Boston Public Library was accessed at the Internet Archive on 29 April 2015.)