The Gran Chaco is a 100,000 square mile area between the Andean foothills of Bolivia, the Pilcomayo River and the Paraguay River. It consists of swamps, rough pasture land, tropical timberland and dense jungle. Two thirds of the year it's extremely hot and arid, while for a few months there is torrential rainfall. In spite of this, both countries desired to own the Chaco Boreal for their own different reasons. Bolivia, having lost it's access to the sea in the Pacific War of 1879 - 81, now looked to the Rivers Paraguay and Parana as a way to reach the River Plate and the Atlantic. While Paraguay, in debt to Argentina after it's defeat in the War of the Triple Alliance [1864-70], allowed the latter to cultivate cattle and timber industries in the Chaco. Also a number of foreign companies had prospected for oil in the Chaco with positive results. Incidents between opposing garrisons within the Chaco increased in number between 1928 and 1932, while both countries made large arms purchases from France [Paraguay] and Vickers of England [Bolivia]. At the start of the war Bolivia, with a population of 3 million, was strong in aircraft and could afford expensive modern weapons such as tanks and flamethrowers, but were weak in artillery. Also as the Bolivians were mainly from a mountainous countryside they did not acclimatize to the Chaco very easily. The Paraguayans. with a population of under a million were weak in aircraft but had modern artillery and superior leadership. Both would prove decisive in the war. In September of 1932 the Paraguayans successfully encircled and captured the fort of Boqueron taking 2,000 prisoners, 50% of Bolivia's field forces. The Bolivians after withdrawing and regrouping at Ballivian, launched a costly and unsuccessful counter-offensive in December, aimed at Alihuata and Nanawa resulting in 2,000 killed. In July 1933 another costly attack was made on Nanawa. The Paraguayans responded in September and October with offensives that netted 1,000 prisoners, with 8,000 more at Campo Via on December 11, pushing the retreating Bolivians past the town of Munoz before a truce was put into effect that lasted until January 1934. During this time both sides reorganised their forces, with Bolivia purchasing further arms from Vickers to make up for it's losses. The Bolivians successfully reasserted themselves by surrounding and capturing 1,500 Paraguayans at Canada Strongeston on May 25th. Another encirclement of Paraguayan forces seemed eminent when the Paraguayans attempted an unsuccessful encirclement of the Bolivian left flank at Ballivian and were forced to withdraw. But it was the Bolivians who were in pursuit that ended up by being surrounded, losing 4,000 troops at Canada El Carmen on November 15th. The Bolivian defenses were so weakened by this latest defeat that they abandoned Ballivian to the Paraguayans in November 1934. The Bolivians now attempted to attack the rear of the pursuing Paraguayan forces with cavalry, but this cavaly attack was repulsed, allowing the Paraguayans to capture a number of fresh water wells that were vital to the Bolivian forces. A result from these gains was that 4,000 thirsty Bolivians surrendered with the main force maintaining it's retreat. Initiative The Paraguayans, to continue the initiative, conducted a daring raid that threatened Bolivia's oil fields at Santa Cruz and captured another 3,000 prisoners. The last remaining Bolivian stronghold in the Gran Chaco was Villa Montes which the Paraguayans now laid siege to. Frontal assaults were bloodily repulsed and attempts to encircle the remaining Bolivian field forces and another attack on Santa Cruz met with limited success. Faced with stalemate both sides gave in and signed a peace protocol on June 12th, 1935, ending the war. Although Paraguay was awarded 80% of the Chaco both sides had suffered tremendously from the war with both countries economies in turmoil. One operation in which armour was used was the Bolivian attack on Nanawa in July 1933, known as the Battle of Ayala. Ayala and Nanawa were towns held by the Paraguayans which formed a bulge in the Bolivian lines. Both sides had dug trenches and the daily routine of battle followed much the same pattern as on the Western Front of the First World War. At dawn came exchanges of artillery fire with Bolivian air attacks, at noon the unbearable heat lead to a mutual cessation of hostilities, in the afternoon came probing infantry patrols while at night attacks were common. The Bolivians launched a major assault on July 4th, begining with a 15 minute barrage that failed to knock out a substantial number of enemy machine guns, while the detonation of a mine failed due to the fact of it's being dug short of the target. The assault was a pincer movement in which simultaneous attacks from the left and right attempted to cut off and encircle the bulge. The attack on the left was unsuccessful as the infantry were driven back by heavy machine gun fire. The single Vickers 6 ton on that side attempted to clear the Paraguayan trenches by moving forwards and backwards in front of them. Unfortunately it was eventually knocked out by a direct hit. As for the two Cardon Lloyd tankettes, one was knocked out by enemy fire and the other was overturned in a Paraguayan trench. Vickers Tank The Vickers 6 ton light tanks on the right flank faired no better with one breaking down and the other's turret being jammed by machine gun fire. Not only did Paraguayan machinegun fire repulse Bolivian infantry, but equiped with armour piercing bullets they also took their toll of tanks. The intensity of the fighting is suggested by the fact that both tanks were repaired and sent into the battle again and again until all the members of both crews had been wounded. In the afternoon the Paraguayans counter-attacked but with limited success. The next day, July 5th, the assault on the right was repeated with the two Vickers 6 ton light tanks but when one broke down the commander of the Bolivian tank corp refused to let the last remaining tank proceed alone in the face of intensive artillery and machine gun fire, the attack on Ayala and Nanawa had ended. Why Failures? Why were these attacks failures? First off the Paraguayan defenders possessed a number of important advantages. Their intricate trench system combined with numerous machine gun positions made for a very strong defense, while their plentiful reserves could counter-attack and reoccupy any ground lost. The Bolivians themselves were as much to blame for their failure, the mistake to hoard their armour while allowing only a few tanks for the attack assured both the destruction of this small force and the failure of the battle. The Bolivians continued to use tanks during the latter part of the war, to make up for a shortage of troops small groups of tanks were spread out along the front to act as mobile reserves who would conduct local counter-attacks against Paraguayan breakthroughs. It was during the period of Bolivian retreat that the Paraguayans managed to capture a number of Vickers 6 ton type A light tanks, although it is not recorded whether or not they were used in combat. An interesting feature of the Chaco war was the effects of poor climate on armoured operations and the solutions that were used to counter these problems. The intense heat often made the metal bodies of the tanks too hot to touch, while the machineguns 45mm rounds would often expand, jamming the gun or, even worse, fire prematurely without warning. The heat also affected the performance of the radios in the tanks and for this reason communication was often through the use of sirens. Tank crews often passed out from heat exhaustion. To alleviate this problem each tank had two or even three alternate crews to replace the fatigued and wounded in the first crew. Maintenance had to be developed to a very high degree as the climate tended to have an adverse effect on engine performance. Thus while the tanks tended to break down during battle they were also repaired quickly enough to re-enter the fray more than once. Bolivian Order of Battle for "AYALA" The Bolivian left which was to attack the Paraguayan right consisted of: 3 Infantry Battalions of 470 men with 20 machine guns 1 Dismounted Cavalry Regiment with 3 flamethrowers 1 Vickers 6 ton light tank 2 Cardon Lloyd tankettes 2 65mm mountain guns 2 Stokes mortars The Bolivian right which was to attack the Paraguayan left consisted of: 3 Infantry Battalions of 470 men with 20 machine guns 1 Dismounted Cavalry Regiment with 3 flamethrowers 2 Vickers 6 ton light tanks 2 65mm mountain guns 2 Stokes mortars The Bolivian Reserve consisted of: 1 Infantry Battalion behind the centre 2 Infantry Regiments behind the left flank Back to Table of Contents -- El Dorado Vol V No. 1 Back to El Dorado List of Issues Back to MagWeb Master Magazine List © Copyright 1992 by The South and Central American Military Historians Society This article appears in MagWeb (Magazine Web) on the Internet World Wide Web. 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