Categories
WW1 German Armor WW1 Mexican Armor

Protos Panzerauto

German Empire/United States of Mexico (1913-1914)
Armored Car – 2 Built

Before World War 1, armored vehicles had not yet come into fashion. Still early in their development, they could not yet prove their technical and tactical capabilities, but this did not prevent individuals and companies from building new vehicles. One of the companies that decided to build armored vehicles before the war was the German car manufacturer Protos Automobile GmbH based in Nonnendamm and subsidiary of Siemens-Schuckertwerke. At least two vehicles were built and sold to Mexico, the first German armored cars to be exported and see active, albeit limited service.

A Protos at the factory. Based on the external features, like the exposed rear wheels, this is one of the vehicles that was later sold to Mexico. The picture is dated 9th May 1913. Source: Wolfgang Fleischer

An Unknown Start

Nothing is known about the development of the Protos Panzerauto, but it presumably came to light as a private initiative, like many other armored vehicles before World War 1. The possibility that it was originally ordered by the German military is incredibly slim, as the armored car concept had been rejected some years earlier. When trials were held in 1909 with three armored cars, a German Daimler model and two French CGV 1906s, as well as one unarmored car, the German high command decided against their adoption. The armor was considered an unnecessary burden to the mobility of a vehicle, without providing sufficient protection. The lack of off-road capabilities and high maintenance costs were also decisive factors.

The Manufacturer Protos

The Motorenfabrik Protos was founded in 1899 by Dr. Alfred Sternberg. Initially, vehicles with small 1-cylinder engines were produced, but Sternberg started the development of larger and more powerful engines. Soon after, he introduced a 2-cylinder engine and in 1904, a 30 hp 4-cylinder engine. An improved model of this engine came out later and was able to produce 42 hp. This engine was used in E1 model cars. It seems that production of these models started in 1906 when the workshop moved to Reinickendorf, Berlin. In the summer of 1908, Oberleutnant Koeppen used a Protos E1 to win an automobile race around the world, leading Protos to become a renowned brand.

An E1 chassis. Supposedly, the armored car was based upon one of these. Source: bungartz.nl

In October 1908, Protos was bought by the Siemens-Schuckertwerke [SSW] and became a division of that company. Manufacturing moved from Reinickendorf to SSW in Nonnendamm, Berlin. SSW had already been producing electrical vehicles and now, with the acquisition of Protos, also got a strong petrol car construction branch.

Protos cars being made in their plant in Nonnendamm, Germany, in 1913. Source: Siemens Historical Institute

Design of the Panzerauto

The design of the vehicle was quite simple and, in some ways, everything that is to be expected of an early armored car. It was based on a regular commercial chassis, a Protos 18/42 Typ E1 that was first introduced in 1906. The 4 cylinder, 4.56 l petrol engine produced 42 hp and was placed at the front, protected by armor. It could be accessed via hatches from either side, which hinged upwards. The armored louvers on the front could be closed from within the crew compartment by a special bar placed over the engine compartment. Two large headlamps were mounted on the front of the vehicle, while two smaller ones were fixed just behind the engine, on the crew compartment.

A Protos in Mexico. A person is just entering the vehicle. Presumably, this picture was taken on 16th September 1914 during a parade. Note that the louvers are in the opened position, allowing efficient cooling while driving, but they could be closed easily by the bar on top. The machine gun is covered by a tarp. Source: Félix Miret / Fototeca Antica

The headlamps were of the acetylene type, known as ‘carbide lamps’. They worked by putting a piece of calcium carbide on the bottom while water was placed in the top part. This would drip down on the carbide and the chemical reaction that follows would form acetylene gas, which was lit, producing the light.

The crew compartment was located behind the engine. The driver sat on the right and could see through two large hatches in the front and a small closable hatch on his right hand side. No vision slits were made in the front hatches, so they could not be fully closed during driving. To the left of the driver, there was space for another crew-member, likely a commander or observer, but he would have blocked the sole entry point of the vehicle.

A rare top down view of the Protos, showing a driver and seven soldiers within the vehicle. Based on the crowd and the use of umbrellas, this picture seems to also have been taken during the parade on 16th September 1914. Source: Mediateca INAH

The whole crew had to enter through a door on the front left side of the hull. Central in the crew compartment, on a raised platform, stood a water cooled 7.92 mm MG 08 machine gun on a pedestal which could also be used against elevated targets, such as potential aerial targets. When standing on the platform, the gunners and crewmembers would largely be exposed to enemy fire, but the machine gun was equipped with a gun shield to provide at least some protection. Furthermore, on both sides of the vehicle, two small closable hatches were located, which could be used by the crew to see through, or potentially to fire through with handheld weapons. Apart from the driver and commander/observer, there was room for at least six more men, including the gunners.

It is unknown what the rear looked like, since there are no photographs or descriptions of it, but photographs from the side and top seem to suggest that it was a flat vertical panel.

The wheels were shod with, what appear to be, regular pneumatic tires and suspended by leaf springs. The vehicles had common wooden spoked wheels, which were possible to be protected with an armored disk as seen on one photograph.

This unique photograph shows two vehicles together during a parade in Mexico. It is unknown if more than two were received. Source: Mexican Military Firearms on Facebook

Protection

In terms of armor, a figure of 3-4 mm is given. If this is true, this would have been inadequate to effectively act as armor, as many projectiles would be able to penetrate it. Without being able to provide proper protection, the weight of the armor would only act as a disadvantage for the vehicle, making it unnecessarily heavy. That said, a variety of early armored vehicles were very thinly armored, like the Austro-Daimler Panzerautomobil with just 4 mm and the Ehrhardt BAK with just 3 mm, to name a few.

In case the given figure is wrong, one expects at least 6 mm of armor, the minimal thickness required to expect decent protection against bullets, at least when high quality steel is used, like a chrome-nickel alloy. Most armored cars that were built since 1914, although not all of them, featured at least 6 mm of armor plating.

One of the first images taken of the Protos after it arrived in Mexico. Note that the text on the side reads “República Mexicana Ejército Nacional”. Later, “1er Regimiento De Artillería” was added below it. Source: zen.yandex.com

Transatlantic Export

In 1910, a revolution broke out in Mexico. Armed forces, led by Francisco Madero, Pascual Orozco, and Pancho Villa, engaged with government troops to contest the regime of President Porfirio Díaz following rigged Presidential elections. Díaz was forced to resign in May 1911 and went into exile. New elections in October made Madero the new president of Mexico. His presidency was tumultuous and, as former President Díaz put it, Madero had unleashed a revolutionary force he was not able to control.

During the Ten Tragic Days in February 1913, Madero and his Vice President were forced to resign and were assassinated after a military coup led by General Victoriano Huerta, supported both by the United States (until March) and the German Empire. In this context, at least two Protos Panzerautos were ordered by Huerta in early 1914. They were shipped to the port city of Veracruz, where they arrived either in July or early August.

However, on 15th July, Huerta was forced out of office by a coalition of several revolutionary forces that included the Constitutionalist Army of Venustiano Carranza, the Zapatistas of Emiliano Zapata, and the Villista of Pancho Villa. The Federal Army was officially dissolved on 13th August. Therefore, the Protos never saw any service with the Federal Army of Huerta. When the vehicles were transported from Veracruz to Mexico City, where they were unloaded at the Buenavista Railway Station, they fell into the hands of the Constitutionalist Army of Venustiano Carranza, which had entered Mexico City on 20th August. On 16th September, a Protos was used during a parade through the streets of Mexico City.

The Mexican Protos as it was being transported by rail. Note that this time, the louvers are fully closed. A colorization by Johannes Dorn. Source: Mediateca INAH

Shortly after the defeat of Huerta, the revolutionary coalition was dissolved and the Constitutionalist Army of Carranza saw itself fighting against the Conventional Army of Pancho Villa and Zapata. Based on photographic records, the Protos did not see much fighting. Instead, one seems to have broken down as, in one image, attempts can be seen to tow it away, while in another image, the rear axle is visibly broken. This was probably because the chassis was overloaded by the combined weight of the armor, machine gun, and the crew. Eventually, the vehicle was stripped of its accessories, including the headlamps and the armament. In this sorry state, it was likely captured by the Conventional Army when they entered Mexico City in December 1914. The vehicle disappeared afterwards and was probably scrapped. If the second armored car saw any service beyond 1914 is unfortunately unknown.

The abandoned vehicle, still with its headlights and armament. The ropes attached to the front suggest an attempt has been made to tow the vehicle, either to this place, or away from this place. The location is the Buenavista Railway Station. In January 1917, this picture was widely published in US newspapers under the caption “Carranza’s Armored Motorcar”. A colorization by Johannes Dorn. Source: IFS / Dutch National Archives
The Protos in a later state, still at the same location as the previous image. The broken rear axle can clearly be seen from this angle. The headlamps and armament have been removed, since they would not have any more use on this broken down vehicle. A colorization by Johannes Dorn. Source: Secretaría de Cultura [inv. 465619]
Two from the same group of men are now posing within the vehicle, which had broken down and stood abandoned for quite some time at the Buenavista Railway Station in Mexico City near the end of 1914. Source: fotografosdelarevolucion.blogspot.com

The Protos and Other Armored Vehicles in Mexico

The role of armored vehicles during the Mexican Revolution is very obscure and unfortunately ill-documented. It is for sure that by 1913, at least one armored train was used and that by 1914, three armored cars were in use, including two Protos in Mexico City and another armored vehicle in Northern Mexico that was used by the Brigada Zaragoza. This particular vehicle was also capable of traveling by rail. Later, the Salinas tank was built in 1917 by TNCA. Furthermore, around 1920, at least two other armored car designs were produced, and several features of these show a striking resemblance to the Protos. Both Protos vehicles, like most of these other armored vehicles, seem to not have been used extensively, probably due to the early breakdown of one.

One of the two armored vehicles that was built around 1920. The shape of the bonnet is similar to that of the Protos, which could suggest some inspiration. Source: relatosehistorias.mx
Another armored vehicle, designed by General Alfonso R. Gomez, which was built in the early 1920s. How many of this type were built is unknown, but possibly quite a few. Again, there are some features strikingly similar to the older Protos, like the presence of two large vision hatches in the front, small gun/vision ports in the sides, and the cutout in the armor for the rear wheel. Source: revistabicentenario.com.mx

A German Vehicle?

For a while, it was thought that a third Protos Panzerauto was built and used by Germany against the Russian Empire in the First World War. A wartime Russian publication called The Mirror published two photographs of a Protos, reportedly after capture. There is, however, no further evidence to support this claim, and these appear to be pre-war photographs. The photographs appear to show a unique Protos, with protective discs put over the spoked wheels and armor that extends over the rear wheels. However, this could well be explained by the notions that the discs were easily demountable, while the rear armor was maybe an earlier or later design iteration proposed by Protos, but never adopted. Provided the relatively poor quality of the pictures, contemporary manipulation of the photographs should be taken into consideration as well.

There is clear evidence for at least one armored vehicle that was present in East Prussia in the early days of the First World War, namely an armored truck of the Benz-Werke Gaggenau. The Protos joins the list of two French Charron Girardot Voigt 1905 models which were possibly still available as well, but there is no further evidence to purporter either claim.

These two pictures were published in a Russian newspaper, reportedly after the vehicle was captured by Russian troops from the Germans in East Prussia in 1914. The vehicle does not seem to have battle damage. Differences with the Mexican vehicle include an armored body extended over the rear wheel, and disc wheels instead of spoked wheels. Source: Rainer Strasheim / Stanislav Kirilets

Conclusion

The current knowledge on the Protos Panzerauto mainly stems from the available photographs, once again highlighting the importance of imagery for our understanding of the past. Long forgotten, the vehicle was rediscovered relatively recently and is gradually receiving more attention. The vehicle was a typical early armored vehicle, with some design issues, including an overly exposed armament. It was the only armored car designed by Protos, one of the first armored vehicles deployed during the Mexican Civil War but, just like the others, still shrouded in mystery.

The Mexican Protos had no disc covers on the wheels, and a cutout was made in the armor for the rear wheel.
The Protos as seen on two pre-war photographs, with the armor partially overlapping the rear wheel, and all wheels being protected by added discs. Both illustrations by Andrei ‘Octo10’ Kirushkin.

Specifications

Approximate Dimensions [LxWxH] 4,5 x 1,8 x 2 m [14.8 x 5.9 x 6.6 ft]
Crew 4-7? (driver, commander, 2-5 gunners)
Propulsion Protos 18/42 PS, 4-cylinder, 4.56 l, petrol, 42 hp
Armor 3-4 mm [0.12-0.16 in]
Armament 1x 7.92 mm MG 08 machine gun
Total production 2

Sources

Mexican Protos Armored Car – National Army (Ejército Nacional). México, 1914, José Luis Castillo, 13 December 2011, armoredcars-ww-one.blogspot.com.
Panzerauto Protos (German Armored Car) M1913, José Luis Castillo, 22 January 2015, armoredcars-ww-one.blogspot.com.
Panzerkampfwagen: im Ersten Weltkrieg, Typenkompass, Wolfgang Fleischer, 2017, Motorbuch Verlag.
Panzer-Kraftwagen: Armoured Cars of the German Army and Freikorps, Tankograd 1007, Rainer Strasheim, 2013, Verlag Jochen Vollert.
Siemens Zeitschrift Juli 1925: Die Geschichte des Protoswagens, Dipl.-Ing. M. Preuß, Automobilwerk der SSW, Siemens Automobilmotoren, bungartz.nl.
“Autos aus Berlin: Protos und NAG” von Hans-Otto Neubauer, Verlag W. Kohlhammer GmbH, Stuttgart 1982, Protos Motoren Vorgänger der Siemens-Motoren, bungartz.nl.
The Protos: Siemens as an automobile producer, Siemens Historical Institute 2018, pdf.

Categories
WW1 Mexican Armor

TNCA Salinas

United States of Mexico (1917)
Heavy Tank Prototype – At Least 1 Built

Mexico is not a country which is often associated with tank production of any kind. What is more, as of 2018, Mexico does not have any tanks at all in their army – their armored forces consist of armored cars, most numerously the Panhard ERC, which is nearing 35 years of service. As such, it may come to a surprise that in 1917, Mexico joined a very select group of tank producing nations with the TNCA Salinas, and by doing so, beating their bitter rivals north of the border.

Context – The Mexican Revolution

The Mexican Revolution is one of, if not the most important events in Twentieth-Century Mexican history, completely changing the sociopolitical fabric of society. For over three decades, Mexico had been ruled by what is known as el Porfiriato, in other words, the presidency of General Porfirio Díaz, until he was forced to resign in 1911. Shortly before that, after fixing an election result in 1910, the people were mobilized against Díaz.

During his presidency, Díaz had made many enemies, and his successor was one of them, the liberal Francisco I. Madero who tried to introduce democracy and freedom of press and association. Following such a long lasting period of rule by one person, a political vacuum was created in which different political elites and social groups fought to take power. Madero had enemies on all sides of the political spectrum – some viewed him has too reactionary, and others as too liberal revolutionary – so he was forced to resign alongside his vice president in a coup in February 1913, with both being assassinated soon after. The counter-revolutionary General Victoriano Huerta took over after the coup and ruled in a dictatorial manner until July 1914, when he resigned and went into exile after a series of defeats of his Federal Army.

By this point, Mexico was submerged in a full-scale civil war. A coalition of revolutionary forces would take over the capital and therefore seized power, but not for long as they failed to land an agreement to form a government. The conservative Venustiano Carranza, who had been instrumental in the coup against Huerta in 1913 and had support from the USA, emerged triumphant from the chaos of the civil war, defeating the famous revolutionaries Pancho Villa and Emiliano Zapata along the way. With the signing of the Constitution of 1917, the situation would stabilize for some time.

Following the signing of the Constitution and up to 1920, clean-up operations were carried out and agrarian revolutionary leaders were assassinated or imprisoned. The general atmosphere of turmoil and uncertainty benefited radical ideas and banditry alike. The ten years of continuous warfare would leave between 1 and 2 million dead Mexicans, including military and civilian deaths.

The Steps Towards Tank Production

Mexico had never been a major arms producer and had always had to depend on foreign imports for any major military operation. The constant situation of warfare during the Revolutionary period exacerbated the need for armament. With this in mind, a pro-government group (Constitutionalists), under the orders of General Venustiano Carranza, led a project to build armament factories for home production in 1915. By 1917, the Escuela Militar de Aviación [Military Aviation School] and Talleres Nacionales de Construcción Aeronáutica (TNCA) [National Aircraft Construction Factories] were inaugurated in Mexico City.

TNCA had originated as a small repair workshop and spare part supplier for the equally small Mexican air-force but slowly increased in size with the introduction of heavy machinery imported from Europe. Eventually, it would even produce its own aircraft, including the TNCA A to H Series and a few licensed British and American aircraft.

At some point in between 1916 and 1917, Carranza’s nephew, the aviator Major Alberto Salinas Carranza, is attributed to having designed a tank which would receive the name ‘TNCA Salinas’ – TNCA after the factory where it was built and Salinas in honor of its designer – although the tank is more commonly known as ‘Tanque Salinas’ (Salinas’ tank).

The TNCA Salinas next to its presumed designer, Major Alberto Salinas Carranza. The five-barrel revolving cannon can be appreciated in this photo. The vehicle is probably perched on some sort of stand. The rollers for the track are visible as are the spaces for the track tensioners although no track is fitted – source: Reporte de Batalla

What ideas were behind the need for this tank are unknown. By 1917, the civil war and consolidation of power by Carranza were all but complete. One must also consider that unlike the Great War in (mostly Western) Europe, warfare in Mexico had not been limited to trenches. In the vast plains and deserts in the center and north, horses and mounted mobile warfare was still important, whilst in the jungles of the south, guerrilla warfare was favored. Tank technology at the time was not advanced enough for tanks to cover these large distances and to fight in this typically mobile warfare. The tank would have been more suited to the multiple urban combats that occurred during the Revolution and to put down uprisings within cities or towns.

Tanks were a new phenomenon and states around the world did not want to be left lagging behind in adopting this technology. Mexico would not be left either, and within an atmosphere of war favoring technological innovations, eager and adept engineers like Salinas could have been free to develop their ideas.

Visit of German Navy personnel to the Fábrica Nacional de Armas. Behind them, the TNCA Salinas. Unfortunately, there are no testimonies as to what impression the vehicle caused on the German visitors – source:

Design

Externally, the tank resembles the early British rhomboid tanks (such as the Mk. I) which had tracks on each side surrounding the hull and covered the entire length of the machine. Its main gun position, however, owes more to the contemporary French design of the St. Chamond.

On each side, there were sponsons to carry the secondary armament consisting of a machine-gun on each side (unlike the British tanks where the main armament would be on the sponsons). The sponsons, unlike the large square British ones, were curved and shaped like a British pillar-box. Also, unlike the British detachable sponsons, these seem fixed to the side. Atop the tank, there was a large box-like cabin – similar to those on the Mk.V (and other later ‘rhomboid’ tanks) – for the driver and commander.

It seems from photographic evidence that in front of the sponsons there were doors for crew access on each side, which, in combat, would have been quite a design flaw as: a) the machine guns would not be able to fire forward if the door was in use; and b) crewmembers would be vulnerable when exiting the tank in middle of combat if the door was facing forward.

Armor details are not described, but given that the vehicle is estimated to be around 7 m in length and 20 tonnes in weight and a similar vehicle, the Mk.I’s 7.9 m and 27-29 tonnes with 6-15 mm in armor, the armor of the TNCA Salinas can be approximated to 6-12 mm. This armor was riveted, and from the photos, it seems it was constructed onto an internal frame.

Armament

The front upper hull had a large square through which the gun was fired. It seems the gun was not fitted into the hull but rather mounted internally and the gun’s original gun shield was used for interior protection. Some sources state a 47 mm Hotchkiss revolver cannon consisting of five barrels as the main armament, but this may well be a typo. It is documented that at the time of the Mexican Revolution there were Hotchkiss 37 mm Revolving Cannons, also with 5 barrels, but there is not mention of a 47 mm variant, and the description provided matches that of the 37 mm. A typo between a 3 and a 4 is easy to make and with time, this typo has come to be accepted as a fact.

Martínez Hernández et al., probably the most reputable source on the tank, state that it was, in fact, the 37mm version, which could have been found on board the battleship Ignacio Zaragoza. This gun was accurate and had a quick reload time, but had its drawbacks, including the fact that it did not have a long range and that it was quite heavy as it was mainly intended to be used on ships or coastal defense (though it was used as field artillery during the war), not early tanks. Each round weighed around 1.1kg and that the gun with a muzzle velocity of 455 m/s. Firing a solid AP shot this gun could perforate 45mm of steel at close ranges.

Some sources mention that an unspecified 75 mm gun, though it could be the Mexican variant of the 75 mm St. Chamond field gun known as the Mondragón-St. Chamond, was also tested, but there is no conclusive evidence of this. The caliber or make of the side machine-guns is not known.

A Hotchkiss 37mm Revolving Cannon at Fort Copacabana, Brazil. Photo: Wikimedia Commons

Inside the Tank

Inside there would be a crew of between 6 and 8. A commander, a driver, two to three crewmembers to operate the main gun in the front and two machine gunners (one on each side). The potential eighth crew member is unspecified but could have been an engineer.

Details concerning the engine differ, but what is assumed is that it would have been a diesel engine of around 90-100 hp. The 6 cylinder Aztatl 80 hp – the first Mexican indigenous airplane engine – could have, according to all available sources consulted, been used, as it was first produced in 1917. Alternatively, at this time in Mexico, there were Hispano-Suiza 150 hp, Wright 60 hp, and Renault ~60 hp engines for aircraft which could also have been used. However, it could make more sense to think that the tank would have used some sort of truck engine, which would have been much more readily available and in less demand than the latest type of aircraft engine. It is worth mentioning though that TNCA was a company involved in aircraft parts production and as such, could have used an aircraft engine which would have been available at the time.

On the other hand, Martínez Hernández et al. doubt that the tank had an engine at all. In the few available images of the vehicle, there are no obvious signs that it ever moved under its own power, so it could well be that whatever engine was desired was never actually fitted.

Side-view of the TNCA Salinas in which its postbox-like sponsons can be appreciated. The identity of the man posing with the tank is unknown – source: Reporte de Batalla

Short Operational History and Demise

It is unknown if any additional vehicles to the prototype were produced in series, but it is highly unlikely. There is also very little information regarding what happened to the tank.

Speculation exists within the sources that the tank could have been deployed in combat twice, though this is highly unlikely. The first supposed use would be in some period between 1919 and 1921, during the last stages of the Mexican Revolution, and the second in 1926 in putting down the Catholic clerical rebels during the Cristero War (1926-29). As previously stated, there is no supporting evidence of this, so, for now, these will be left as conjecture.

The company TNCA was eventually bought by Canadian Car and Foundry, but before then the company was on a spiral decline due to lack of government investment and a preference for foreign aircraft.

The ‘Tanque Salinas’ would end its operational life sometime during the 1930’s when it was converted into a guardhouse or checkpoint outside the air base at Balbuena, near Mexico City, not too far from where the tank was originally built. The main gun was removed and from photographic evidence.

It is unknown what happened to the tank after this, but it was most likely scrapped at some point. Mexico would not have any other tanks until the nine Marmon-Herrington CTVL tanks acquired from the USA in 1938.

The Tanque Salinas presumably at the Balbuena air base lacking its main armament. In this picture, it can be perfectly appreciated that the gun was not affixed to the frontal plate but rather mounted internally and protected on the inside only with its gun shield. The open space seen through the gun opening would have been the open right-hand-side door – source: Reporte de Batalla

Conclusion

Although the TNCA Salinas was never going to blaze the trail for a new tank concept, but it was an important milestone in the history of tank design by being the first tank designed and built outside Europe. Unfortunately, not much is known about the tank and there is very little scholarly work on the history or development of the vehicle, which is unfair given its importance, meaning that it deserves a better legacy.

Its design proved that the Mexican engineers and elites were not only aware of events happening in Europe but were able to adopt various different ideas (a rhomboid design and forward facing main gun not mounted on sponsons) into one suited to their own purposes. That said, it is unknown how well, if at all, Tanque Salinas worked, and it was most likely never used in combat or even in training operations.


Illustration of the Salinas Tank modeled by Mr. C. Ryan, funded by our Patreon Campaign.

Specifications

Dimensions (L-W-H) Est. 7 x 3 x 2 m (22.96 x 9.84 x 6.56 ft)
Total weight Est. Around 20 tonnes
Crew 6-8 (Commander, Driver, 2-3 Gunners, Two Machine Gunners, possibly 1 Engineer)
Propulsion 6-Cylinder Aztatl 80 hp
Armament Naval 37 mm Hotchkiss revolver cannon
2 x machine guns
Armor 6-12 mm (0.24 – 0.47 in)
Total Production 1

Bibliography

Anon., Gral. Div. P.A. Alberto Leopoldo Salinas Carranza (2011). (LINK) [accessed on 30/08/18]
Anon., The Hotchkiss 37mm Revolving Cannon (2010). (LINK)
‘Coldown’, El primer tanque de Latinoamérica (2016). (LINK) [accessed on 29/08/18]
David Cummings, TNCA Salinas (Tanque Salinas), Mexico’s First Indigenous Tank (2013). (LINK) [accessed on 29/08/18]
Samuel Banda, TNCA Salinas: El primer tanque mexicano (2012). (LINK) [accessed on 29/08/18]
‘Tlileztly’, TNCA Salinas “Tanque Mexicano inicios del siglo XX (2017). (LINK) [accessed on 29/08/18]
Mario Alejandro Martínez Hernández (ed), Sentinel Dossier 1 El mundo de las fuerzas armadas mexicanas (Marzo 2016)
Philip Jowett and Alejandro de Quesada, Osprey Elite #137 The Mexican Revolution 1910-20 (Oxford: Osprey Publishing, 2008)

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