1. The home front

By the end of 1867 the Allies were badly in need of a propaganda victory. The war had cost them a lot of men^[27][28] and money; though they still had superior manpower^[24] yet they were stuck in the small area of southwestern Paraguay shown in the map. The disaster of Curupayty had sunk their morale^[29][30] and led to a year's inactivity.^[31][32] And it had fostered an already strong anti-war faction in Argentina. Armed revolutions had broken out in that country – especially in the Andean provinces – demanding peace with Paraguay.^{[33][34][35][36]} It had got to the point that the Allied commander-in-chief General Bartolomé Mitre had temporarily quit Paraguay^[37] with 4,000 Argentine troops in order to put down the revolts,^[36] leaving the Brazilian General the Marquis of Caxias in charge.^[38]

Brazil financed its warlike operations partly by borrowing in the financial markets especially the City of London,^[39][40] and advanced money to Argentina and Uruguay.^[41] The lack of progress in the war was affecting its financial credit.^[42]

In June 1867 Caxias wrote to a colleague:

My friend, let us see if we can conclude this cursed war which has ruined our country, and whose duration shames us.^[43][44]

2. Extended lines of communication

Lengthy lines of communication vastly increased the difficulty and cost of the war for Brazil. According to the American envoy to Paraguay, López had banked on that fact when deciding to make war on the Brazilian Empire in the first place.^[45]

Steam vessels were the only practicable means of communication. Thus in Brazil the overland journey from São Paulo to Mato Grosso took two and a half months by fast mule; by steamship, although the detour south through the River Plate and up through the River Paraguay was vast, it could be done in little over a fortnight.^[3][46] Tension over this route had been one of the causes of the Paraguayan war.^[15]

Ammunition or other stores shipped from Rio de Janeiro, Brazil to the naval arsenal at Isla del Cerrito, near the mouth of the river Paraguay, had to travel an extensive water route.

Vessels requiring to be repaired could not be sent down to Buenos Aires for lack of facilities, and Rio de Janeiro was too far. Isla del Cerrito ("island of the hillock") was and is a small island at the confluence of the Paraná and Paraguay rivers. There the navy established a machine shop employing 20 men; a boatyard manned by 50 carpenters, etc; a coal bunker; a gunpowder mill; a naval hospital; and even a church. Good naval timber required for repairs was harvested locally.^[49]

Because the river was blocked at Humaitá, stores required further north had to go by oxcart convoys on a route flanking Humaitá to the east. Those convoys were the object of repeated Paraguayan ambushes.

3. Inherent difficulty in effecting the naval passage of Humaitá

Although some foreign observers^[50][51] were critical of the Brazilian navy's lack of zeal and implied that it should have forced the passage long ago,^[52] those observers were not naval men. One who was, Commander Kennedy^[53] of the Royal Navy, wrote that there were real difficulties, which he identified as these:

1. The river approach to Humaitá – which included the heavily armed preliminary fortifications at Curupayty – was shallow, narrow, and uncharted.
2. It lent itself to the release of "torpedoes" (improvised contact naval mines).
3. It was too shallow for the heaviest ironclad vessels, except during the river's seasonal rise.^[55] The seasonal difference between high and low water could be as much as 3 fathoms (18 ft; 5.5 m).^[56]
4. But if these vessels did proceed at high water, they might be grounded, or trapped (neither able to advance or retreat), when the waters fell again.^[57]

Commander Kennedy's evaluation:

It is difficult to conceive a more formidable obstacle to an advancing squadron than this small portion of the river between Tres Bocas and Humaitá.

Further, although ironclad vessels were not supposed to be sunk by river batteries of the type possessed by Paraguay, they could be badly damaged.^[58][59][24] Cannonballs sometimes did penetrate the hull by going through a porthole or gunport.^[60][61] When this happened the shot could fracture or ricochet around inside the casemate producing appalling carnage.^[62][63][64] And even though most shots did not get inside the hull their force could start the bolts of the iron plating,^[65] or produce combat wounds by splintering the wooden backing.^[66] For inexperienced seamen inside these vessels the effect could be terrifying.^[67]

In any case it would have been necessary, somehow, to cut or evade the chain boom, or else be detained under the Paraguayan artillery indefinitely.^[68]

According to the English-language Buenos Ayres Standard

Experienced American and English and French naval officers, who had seen Humaitá, inspected the position, and gone through the batteries, all unanimously agreed on its extreme strength.^[69]

4. Dissension amongst the commands

The capture of Humaitá was an early example in modern warfare of combined operations, requiring cooperation between land and naval forces but as will now be described there were serious problems.

Argentina and Brazil were traditional enemies.^[70] The alliance between them was that of "dog and cat",^[71] only brought about when López declared war on them both;^[72] it was fraught with mistrust and veiled antagonism.^[70] For political reasons the Argentine General Bartolomé Mitre was nominally commander-in-chief,^[73] but this went down badly in Brazil^[74] whose land forces were much larger;^[75][70][76] in reality Mitre had to seek consensus with the Brazilian and Uruguayan commands.^[77]

Further, the Treaty of the Triple Alliance had stipulated that the naval forces (to all intents and purposes the Brazilian navy, for the Argentine naval forces were small)^[64][78] were to be "under the immediate command" of the Brazilian admiral;^[79] and the Brazilian government made it plain that the navy was not taking orders from Mitre.^[80]

During the war the Brazilian navy had been criticised for its inertia.^[81] It was the modern ironclad vessels of the Brazilian navy that had stood by and allowed the retiring Paraguayan army to escape across the River Paraná on rafts – together with 100,000 head of rustled cattle – without doing anything to stop them.^[82] Those same vessels had been defied by two Paraguayan chatas (flat-bottomed, towable barges mounting a single gun).^[83][84] Although the Brazilian naval command protested that the shallow river waters enjoined caution,^[85] the Brazilian soldiery and the Emperor Pedro II were disgusted.^[86] As a result, the Brazilian Admiral Tamandaré had been relieved of his command and Joaquim José Inácio^[87] (1808–1869) had taken over his functions^[88] on 2 December 1866.^[30]

The naval command was thoroughly distrusted by General Mitre^[89] and the distrust was mutual, for the Brazilian commands, military and naval, suspected the Argentines would be only too pleased if the Brazilian navy was destroyed in the war, since it would weaken Brazilian power in the River Plate region.^[90] The more Mitre asked the navy to be bold, the more they suspected him.^[80]

In practice Mitre never attempted to give direct orders to the Brazilian navy, instead seeking to persuade it through the senior Brazilian land commander.^[91]

5. Ageing naval command

The new admiral Inácio had had a distinguished and brave fighting career in the days of the blue-water sailing navy. But he had not been to sea for years, pursuing a career as a bureaucrat and then a politician. In Paraguay Inácio became unwell, a prematurely old man, "a ghost of an admiral", as the modern Brazilian historian Francisco Doratioto put it.^[92]

According to Artur Silveira da Mota, commander of the ironclad Barroso (who was a full naval captain by the age of 26, and later in life given the rank of admiral and made Baron of Jaceguai) "most of the senior naval command showed themselves to be incompetent for war service, whether for advancing years or for being too long in sedentary jobs",^[93] an assertion with which Doratioto was inclined to agree.^[94]

No armoured vessels

In particular, she did not possess a single ironclad vessel. She had placed orders for ironclads at British and French shipyards, but López had attacked Brazil and Argentina without waiting for these to be delivered. Because of the blockade he stopped making payments. Brazil negotiated to purchase the work-in-progress and to have it completed; and hence took delivery of the ironclads Bahia, Colombo, Lima Barros, Cabral and Silvado, all of which were originally destined for Paraguay.^[97] According to Burton it was the general opinion that with just one ironclad Paraguay could have cleared the river.^[98]

Little armour-piercing weaponry

She also had little armour-piercing shot,^[65] and for the same reason. According to the diplomat Gregorio Benítes, who represented Paraguay abroad during the war:

If Marshal López had not been precipitate in accepting the war, to which he was provoked by the Empire of Brazil, and had he given himself time enough to take delivery of the great monitors and armaments which he had ordered in Europe, among the last some 36 coastal artillery pieces made on the Krupp system, contracted for in Germany with the personal intervention of the undersigned, then not a single fresh-water ironclad would have been able to attack the aforementioned fortresses with success, if they had been armed with that powerful artillery.

In effect, whoever has any idea of the formidable power of Krupp artillery, will understand that such cannon being mounted in the batteries of Curuzú, Curupaity and Humaitá, the triple alliance would not have had one single ironclad which could venture under their fires, on pain of certain disaster. Furthermore, López left it too late to order these weapons; so that the Baron of Itajubá the Brazilian accredited diplomat in Berlin, on finding out about the acquisition of those cannon on behalf of Paraguay, made use of his right under international law to require the detention of the said artillery.^[99][100]

The Brazilian ironclads dash past the lower fort

On 15 August 1867 at 0640 hours the Brazilian ironclads went into action. They were:

In the table the symbol P denotes that the vessel had originally been ordered by Paraguay, but obtained by Brazil in the circumstances already explained.

The Brazilian admiral Joaquim Inácio was in overall command from the bridge of Brasil.^[110] Lashed to the port side of Brasil was the steam messenger Lindoya (to assist her in turning);^[111] Colombo and Cabral each towed a chata (flat-bottomed barge).^[112]

At this point the river had two channels. One was deeper, but it ran closer to ("within pistol shot of"")^[113] the enemy batteries, and the current was stronger. In the other, or shallow, channel the risk of running aground was far greater; furthermore, a Paraguayan deserter claimed torpedoes had been placed there recently. Inácio chose to proceed by the channel closer to the batteries, and his choice was vindicated. While wooden vessels of the Brazilian navy provided covering fire the ironclads dashed past Curupaty. It took each vessel about 40 minutes to get past.^[114]

Even so, some vessels were badly damaged. A shot penetrated Tamandaré through a gunport killing or wounding 14 of her crew. Her engine was damaged and stopped leaving her adrift under the guns of the fort;^[115] she was rescued by Silvado who threw her a cable and took her in tow.^[116] Tamandaré's commander Elisário Barbosa^[116] lost his left arm.^[117][118] According to Commander Kennedy RN the accident to Tamandaré obliged Colombo, which was following astern, to stop her engines in order to avoid fouling her. The strong current brought her broadside on, making her unmanageable. She drifted close to the Paraguayan guns, which did some very serious damage before she could be backed out of her dangerous position.^[111] There were 25 Brazilian casualties including three killed.^[119] The ironclads, by taking the channel nearest to the Paraguayan guns, had escaped a more serious danger, for a number of torpedoes were afterwards found laid down in the other channel.^[120]

For this feat on 27 September Joaquim Inácio was awarded the noble title of Barão de Inhaúma (Baron of Inhaúma).^[113]

According to Paraguay's then chief engineer George Thompson, López gave it out that he had allowed the fleet to pass Curupayty on purpose, to trap it and starve it out, and that it would soon have to repass Curupayty, where he would sink it.^[115] This is corroborated by Juan Crisóstomo Centurión, a Paraguayan journalist working for the López regime at the time.^[121] The government newspaper El Semanario de Avisos y Conocimientors Útiles claimed a victory, writing: "The [Brazilian squadron is wounded in the heart, and we have one part of its ironclads prisoner between Curupaty and Humaitá, devoid of resources, without means of repair, and given over to the fury of our cannon; the rest will have to come to its aid, and follow the same road of shame and defeat".^[122] And "The ironclads must now make every effort to patch themselves up; but the impacts made by the solid shot of Curupayty cannot be repaired, except in arsenals, and none of those can be found between Curupaty and Humaità.^[123][124]

The Brazilian navy establishes a regular steamship line to supply its warships in the River Paraguay

On 4 October 1867 the navy minister Afonso Celso de Assis Figueiredo^[142] by order established a liner service from Rio de Janeiro, Brazil exclusively to supply the Brazilian navy in Paraguay. Using four steamships, it had scheduled sailings, each way, on the 15th and 30th of every month. From Rio steamers stopped to coal at Montevideo, Uruguay and then steamed non-stop to Corrientes, Argentina to drop off correspondence before proceeding to the naval arsenal of Cerrito near the mouth of the River Paraguay. According to Afonso Celso's memoirs whatever the Brazilian vice-admiral asked for was promptly supplied from Rio.^[143]

The Brazilian navy builds an emergency military railway through the Chaco to its trapped ironclads

However, since the ironclads were cut off above the fort of Curupayty, the Brazilian government at once ordered the navy to build a supply line through the Chaco. The Chaco is the territory to the west of the River Paraguay. In those days it was claimed by both Argentina and Paraguay, but was uninhabited, except by a few nomads. In this coastal region it was almost impassable swamp.

The supply line, named Affonso Celso after the minister of marine, ran between two improvised harbours on the west bank of the river, i.e. inland through the Chaco. They were dubbed "porto Palmar" (where the wooden vessels moored, below Curupayty) and "porto Elisário"^[144][145] (above); both were out of range of the Paraguayan guns. The ironclads moored at porto Elisário.

It was possible to travel some of the way by a navigable creek called Riacho Quîá.^[115] From there^[146] the Brazilian navy at great effort built a military railway or tramway. At first drawn by animal power, later by an improvised steam engine, the line carried artillery guns, steam launches and heavy ammunition, as well as coal and other supplies.^[147] It was reported that the line conveyed 65 tons of supplies a day, its sleepers almost floating on the boggy ground.^[148]

The ironclads shell Humaitá

For five months the ironclads stayed in this precarious (and, from a sanitary point of view, deplorable)^[149][150] position, frequently going out to shell Humaitá, but not doing much damage.^[151] The only installation they could clearly see to hit was the church of San Carlos Borromeo, and they fired at it.^[106][152] Wrote Burton: "The Brazilians banged at the fane persistently as an Anglo-Indian gunner at a flagstaff; and the Paraguayans at times amused themselves with repairing it."^[153] Another source says that church was respected at first, but then shelled on purpose because Caxias claimed it was being used as a powder magazine and a watchtower.^[154] Its ruins still stand today, a tourist attraction,^[155] practically the only part of the fortress of Humaitá that survives.

According to Artur Silveira da Mota, Admiral Inácio sank into inertia, rarely leaving his cabin aboard Brasil, instead writing picturesque articles for the weekly Semana Illustrada under the pen name Leva-Arriba (Get Up and Go), "a pseudonym which circumstances did not permit him to confirm by deeds".^[156]

The ironclads sink the chain boom's floating supports

During this time the ironclads did perform one action favourable to the Allied cause: they sank the chain boom.

Formidable as it was, Humaitá had an Achilles' heel. According to military doctrine a chain boom should never rest on hollow floating supports, for the enemy might sink them.

[T]he buoys must be solid, as in a dark or misty night they [hollow ones] are easily scuttled … the Boom must be quite independent of these last as to buoyancy.^[157]

The chain should be secured to solid floating supports; thick wooden logs or condemned ship's masts were recommended.^[157] This detail eluded the designer of Humaitá. In the words of teniente-coronel George Thompson of the Paraguayan army, the chains were

supported on a number of canoes, and on three pontoons.^[158] 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.^[159]

1. The Paraguayans build a supply road through the Chaco

Even before the passage of Curupayty was accomplished López started to build a road through the Chaco to supply Humaitá. It ended at Timbó, the nearest place on the opposite bank where a landing could be achieved. Despite the appalling nature of the terrain the road ran for 54 miles. The greater part of it went through deep mud; the Bermejo River had to be crossed, and five other deep streams.^[160]

The Paraguayan steamers Tacuarí and Ygurey did all the transport work between Timbó and Humaitá, landing opposite the church, and out of sight of the Brazilian ironclads.^[161] Thus even when the Allies had cut off Humaitá by land Caxias could see these Paraguayan steamships continuing to replenish the fortress.^[162]

2. The Paraguayans bring the Curupayty guns to reinforce Humaitá

Since the ironclads showed no sign of retreating below Curupaty, the Paraguayans had time to remove nearly all its heavy guns, convey them by land, and mount them at the next obstacle, Humaitá. Commented George Thompson:

[S]o that the fleet, by its wretched slowness, had to pass the same guns again at Humaitá.^[106]

3. López establishes a surprise battery at Timbó

At the beginning of February 1868 López sent George Thompson to start a battery at Timbò. He placed six 8-inch (20 cm) guns and eight 32-pounders. The bank of the River Paraguay on the Chaco side is low, so the guns were placed on timber platforms.^[163]

As will be described, this battery, whose existence was not suspected by the Brazilians, was even more damaging to their vessels than Humaitá.

First dash

At about 04:00 hours a signal rocket from Barroso announced that the first pair had successfully passed over the chain boom,^[188] by now submerged in the river mud.

Second dash

As this pair was passing the Cadenas battery a shot cut the cable by which Alagôas was fastened to Bahia, and she became detached. Bahia got clear by 04:50 hours,^[190] but Alagoas drifted downstream. According to Inácio's official report, she was ordered to abandon the attempt; but her commander (Lieutenant Maurity) turned a blind eye "like Nelson at Copenhagen".^[191] She then started and passed the site of the chain boom by herself. A shot from the batteries damaged her engine so she fell back a second time. The engineers having repaired her engines, she passed over the chain yet again. This monitor was under fire for two hours altogether, and did not get clear until 0530 hours.^[192]

Third dash

Details

"The Marshall's artillery units fired enormous quantities of shell and canister into the air as the enemy fleet neared", wrote Professor Thomas L. Whigham. "Perhaps one hundred fifty guns were firing simultaneously. The din was terrific, and lasted over forty minutes."^[194]

This was still the era of the wooden warship. Although iron-plated, all of these vessels (except Bahia), were built on timber frames.^{[195][196][197]} It was still possible to be wounded by wooden splinters detached by the mechanical shock of an incoming cannonball − as in the days of sailing ships − and in the ensuing action Barroso had one such case, as did Alagôas.^[198]

Delfim Carlos de Carvalho commanded from the bridge of Bahia.

The ironclads Lima Barros and Silvado provided covering fire.^[191] Meanwhile, the land forces launched a diversionary attack on the Cierva redoubt (called Establecimiento by the Brazilians).^[199]

In command of the fortress of Humaitá was colonel Paulino Alén. Colonel Francisco J. Martinez and the artillery commanders Pedro Gill, Remigio Cabral and Pedro Hermosa directed the river batteries.^[200]

The Paraguayans had foreseen that the Brazilian attempt might be made at night time, and upon detecting the advance of the ironclads they let off rockets along the water's surface to light up the river. They also lit fires at three separate points on the Chaco coast: the light was strong enough to confuse the pilots. The river was so high that there were 12 to 15 feet of water over the chains;^[202][203] the squadron easily passed over. As the expedition kept near the Chaco bank most of the shots fell on the shore.^[204] Even so, the vessels were struck many times.

The two wooden steamers the Paraguayans used to replenish Humaitá hid in a lagoon, and the Brazilian squadron passed by without noticing them.^[205]

Surprises at Timbó

The Brazilians had not appreciated that the Paraguayans had established the other battery a few miles up the river at Timbó;^[199] when they steamed past, its unexpected fire did as much, or more damage to their squadron as Humaitá, because this battery was closer to the river surface;^[180][206] also, by then dawn had broken. Another source suggests that the best guns had been moved to Timbó. According to that source^[192] the ironclads were struck as follows:

Examining Alagôas six months afterwards, Sir Richard Burton noted that the damage to her armour plating was still visible.

The bolts were often started, and the plates were deeply pitted by the 68-pounders, like plum-pudding from which the "plums" had been picked out. In some cases there were dented and even pierced by the Blakeley steel-tipped shot, of which Marshal-President López had but a small supply. Our naval officers have reported that the cast-iron projectiles impinging upon the armour, shivered into irregular fragments, which formed a hail of red-hot iron, and left the gun without a gunner to work it. The battery men always knew when a ball struck the plates at night, by the bright flash which followed the shock^[65]

As Alagôas steamed past Timbó, 20 canoes started from the shore full of armed Paraguayans intent on boarding her. The Paraguayans were attacking an ironclad vessel with canoes.^[192] (When this was reported in the Buenos Aires press some foreigners thought it was an absurd newspaper exaggeration.^[207] But the Paraguayans did it on more than one occasion.) The attackers were rammed or repelled with grapeshot.

Success: casualties and damage

Nevertheless the squadron had forced the passage of Humaitá. The Brazilian naval casualties were: one seriously wounded, nine lightly wounded.^[199] The casualties sustained in the diversionary land attack on the Cierva redoubt (Establecimiento Novo) were very much higher: the Brazilians under General Argolo lost 1200 men.^[1]

Some of the ironclads were severely damaged. Tamandaré received three shots in her bow and was making 6 inches of water per hour. She was obliged to beach at Tayí. Alagoas and Pará had their upper works completely carried away.

While three vessels stopped at Tayí for repairs, the others (Bahia, Barroso and Rio Grande) started upriver for Asunción. But López had already given orders for the capital city to be evacuated.^[205]

News impact

The Passage of Humaitá made news in many capitals and the reputation of the Brazilian navy was restored.

In a special edition, the Irish-edited^[208] Buenos Ayres Standard^[209] said:

The cannon of the Brazilian iron-clads, as they forced the passage of Humaitá, has^[210] re-echoed over this continent, and will reverberate through Europe. No event of equal importance has occurred in this part of the world during the present generation; and, to the high honour of the Brazilian flag, it must be said that the naval victory achieved is every way worthy to rank with Aboukir or Trafalgar… Brazil has at lasted vindicated her honour.

The article praised the bravery and skill of the Brazilian officers and men. The American minister in Rio de Janeiro forwarded a copy to Secretary of State William H. Seward.^[211]

In Rio de Janeiro the British minister George Buckley Mathew advised the Foreign Secretary Lord Stanley:

[It is] a feat that will find its place in the annals of the military and naval science of the age, and that vindicates a high standard for the courage and the discipline of the Brazilian navy.^[212]

The news reached Lisbon on 2 April and was telegraphed to other European capitals, causing a rise in Brazilian and Argentine stocks.^[213] The Brazil and River Plate mails arrived at Southampton on 6 April carrying the South American newspapers; the next day The Times of London printed extensive verbatim extracts describing the passage of Humaitá.^[214] In an era that did not yet have banner headlines, the Glasgow Daily Herald began its report across the top of the first column

THE WAR IN SOUTH AMERICA

THE GREAT NAVAL FEAT OF THE BRAZILIAN IRONCLADS^[215]

An article in the consistently pro-Paraguayan^[216] Colburn's United Service Magazine and Naval and Military Journal, of London, admitted that the Brazilian navy had

achieved what some excellent judges of such matters considered very nearly an impossibility.^[217]

In Paris, L'Illustration, Journal Universel published a full page spread.^[219] It included an engraving of Joaquin José Inácio (now raised to the rank of Viscount of Inhaúma), a letter from the astute diplomat José Paranhos predicting the war would be over in a month, and a depiction of the passage of Humaitá, from a sketch drawn mainly from Paranhos' imagination.^[220]

Public reaction

In Brazil there was "veritable delirium". In Rio de Janeiro bands followed by cheering crowds played through the streets for three days. In São Paulo the houses were illuminated and a te deum service was ordered to be held in the cathedral. The Emperor himself thought the end of the war was near.^[221]

Effect on the Allies' financial standing

The passage of Humaitá came at an opportune moment for Brazil's financial credit. In his official report to Parliament the British consul in Rio de Janeiro remarked that the Brazilian paper currency and the price of government bonds had dropped to half their prewar value and were still falling.

It was by a mere accident that it stopped at that point. A rise in the river enabled the squadron to pass Humaitá out of range [sic],^[223] and turned the tide of the war, raising the rate of exchange by shewing a probability of an early cessation of the hostilities.^[224]

In May 1868 Brazil, which previously had raised a loan in the City of London only by offering it to investors at a very low price,^[225] was able to float a war loan with great success, the offer being greatly oversubscribed.^[226]

Argentina – whose international credit in that era was much poorer than Brazil's, hence did not have the alternative of foreign borrowing in the first place (except for short-term finance)^[226] – enjoyed a similar boost. Whereas in 1867 she had not been able to raise a short-term loan in London at all, even on very onerous terms,^[227] in July 1868 the news enabled her to do so.^[228]