Already at the initial stages of the First World War, all parties to the conflict had to face a number of new problems. One of them was wire barriers, which were notable for the ease of production of the installation, but at the same time seriously impeded the passage of enemy troops. For a successful offensive, the troops needed some means of fighting barbed wire. At the end of 1914, work began in France on the creation of a self-propelled engineering vehicle capable of making passages in obstacles. The project was named Breton-Prétot Apparatus after the names of its creators.
The initiator of work on the creation of a specialized engineering machine was Jules-Louis Breton, a scientist and politician. Occupying his post in the structures of power, J.-L. Breton saw the problems of the army and expressed a desire to help the soldiers in the fight against the enemy. In November 1914, he proposed the original idea of creating a self-propelled protected vehicle with a set of special equipment designed for cutting wire barriers. In the near future, Prétot was involved in the development of the project. This organization had some experience in creating and assembling various self-propelled equipment, which was planned to be used in a new project. The names of the inventor and the head of the production company soon became the name of the project - Breton-Prétot.
Breton-Prétot Apparatus engineering machine being tested
The first version of the Breton-Prétot Apparatus engineering machine had a fairly simple design and in fact was supposed to become a technology demonstrator. It was proposed to mount a set of special equipment on a four-wheeled cart with its own power plant. As part of the latter, a separate 6 hp engine was to be present, connected to a vertically located circular saw. The latter was carried out in front of the base platform on a beam of sufficient length and connected to the engine using a chain drive. Such a machine, in theory, could approach the enemy's obstacles and cut them, making passages for the soldiers of its army.
In November 1914, Breton and Preto proposed the first version of their project to the military department. In general, the military were satisfied, which resulted in the continuation of the work. In January of the following year, Prétot built a prototype of an engineering vehicle with a simplified design. Such a car was released for testing, where it showed its potential. The prototype confirmed the possibility of cutting obstacles, but the practical value of such a machine was not too great. She had no protection, and was also characterized by unacceptably low mobility.
Based on the test results of the first prototype, it was decided to significantly redesign the project. The existing wheeled platform had insufficient characteristics, which is why it was planned to transfer the cutting mechanisms to a new chassis. The characteristic features of the battlefields of the First World War required the use of a tracked chassis with the appropriate capabilities. Nevertheless, the authors of the project were never able to find a free car with suitable characteristics. Because of this, a commercial tractor of one of the existing models was involved in the new version of the project.
At the end of January 1915, the Preto enterprise again brought a prototype of a promising engineering machine for testing. The second prototype differed from the first in a number of features associated with both the use of a new chassis and the upgrade of the target equipment. Outwardly, the prototype looked like an ordinary agricultural tractor with equipment suspended from it. It is interesting that in the future it was planned to equip the car with armor, but during the tests, weight simulators were used instead. As a result, the outwardly experienced tractor with wire cutting equipment did not differ much from the base machine.
Working body of the machine
A Bajac tractor was chosen as the basis for the second prototype of the Breton-Prétot Apparatus. This machine was built according to a classic layout for this technique. The front part of the frame was given for the placement of the engine, and in the rear there was the driver's workplace. There was a four-wheel chassis with a leading rear axle equipped with oversized wheels. To improve mobility on rough terrain, the rear wheels were made of metal and had a rigid structure. The tractor was equipped with a gasoline engine. The vehicle's own weight reached 3 tons. After installing the armored hull, the combat weight could increase by about a ton.
According to the surviving data, it was planned to mount a hull of a fairly simple design on the tractor chassis, capable of protecting the crew and the vehicle from small arms or artillery shell fragments. The tractor engine compartment should have been covered with a U-shaped casing. The cockpit could get a rectangular body with a sloping top. The latter provided for the installation of a machine gun installation for self-defense. Several inspection hatches and slots were to be located along the perimeter of the armored cabin-cabin.
At the stern of the chassis, a block of special equipment was hung, responsible for cutting the wire. A large body was placed on the frame fastening devices, inside which certain units were placed. A horizontal beam departed from the body, which served as a support for the working body. The hull and beam were equipped with their own transmission to transfer the engine power to the cutter. Due to the relatively high weight, the special equipment received its own support wheel.
The working body of the Breton-Prétot machine of the second type was a vertical device with 13 protruding teeth directed backward relative to the tractor. A chain saw was also placed on the base beam of the teeth. The teeth were supposed to bring the barbed wire into position and hold it, after which the chain saw would cut.
Wire cutter on armored tractor
Also, the authors of the project provided for equipping the engineering machine with a large circular saw, placed in a horizontal position. Such a saw had to be at a low height above the ground. It was assumed that with its help, an engineering machine would be able to cut the pillars holding the wire fence. The saw was under the rear of the chassis, between the wheels.
According to some reports, in February or March 1915 J.-L. Breton and Prétot carried out tests of the built prototype, based on the results of which a decision was made to change the project again. The redesign of the structure continued for several months. In July, an updated prototype was released for testing. During the alteration, she lost a horizontal circular saw, and also received ballast that simulates the mass of an armored hull. Eight artillery pieces of an obsolete type made of bronze were used as ballast.
On July 22, the updated engineering vehicle passed new tests, during which all expectations were fully confirmed. The cutting device of the original design effectively destroyed typical wire barriers, forming a passage of sufficient width. In spite of some difficulty in reversing the machine towards the obstacles, the Breton-Prétot Apparatus performed well overall. The military were satisfied, which resulted in an order for the continuation of work and the construction of serial equipment.
Based on the results of July tests, the French military department ordered to continue the development of the project and improve the machine in accordance with existing requirements. After the completion of the project adjustment, it was required to build ten production vehicles. An order of this content was signed on August 7.
Oversized Cutter Mount Option on Protected Truck Chassis
During testing, the Breton-Prétot machine confirmed the characteristics of the cutting device, but some other features of the project could be cause for criticism. The used Bajac tractor did not have high mobility, and in addition, it had to drive up to the barrier in reverse. Such features of the project did not fully suit the customers and developers, which is why the design work was continued. Before the start of mass production, it was planned to rework the project once again using a new chassis.
An improved torch version has been developed for use with other chassis. It was distinguished by a greater height of the working body and the presence of onboard armor plates protecting the units. It retained its own wheel to support it on the ground. Such a project provided for a set of mounts designed to install the cutter on an existing chassis. There were also devices for taking off the engine power to the drives of the cutting chain.
Already in 1915, several alternative variants of the engineering vehicle were created, based on different chassis. In particular, the Jeffrey Quad truck or one of the Renault armored vehicles could become the carrier of the Breton-Preto cutting device. Depending on the type of media, the cutter was placed in the front or back of the body. The most effective carrier of special equipment could be a tracked chassis with acceptable characteristics, however, the implementation of such a proposal turned out to be impossible due to the lack of the required vehicles.
J.-L. Breton and his colleagues continued to work on their project until the very end of 1915. Due to certain design changes, it was supposed to get rid of identified or expected shortcomings. The result of the next stage of design work should have been the emergence of an engineering vehicle with high mobility on rough terrain, equipped with a highly efficient wire fence cutter. It was assumed that such a technique would move in front of the advancing infantry and make passes for it in non-explosive enemy obstacles.
The device "Breton-Preto" on the armored car Renault
While the authors of the Breton-Prétot project continued to develop the original proposals and improve their engineering machine, other French specialists were engaged in other work. By the end of the year, the army and industry tested the Baby Holt tracked tractor, which showed the prospects for such a technique. The tracked chassis had high cross-country ability and could move over very rough terrain. In addition, it had a sufficient carrying capacity.
According to some reports, at the very beginning of 1916, one of the existing Baby Holt machines was experimentally equipped with a Breton-Prétot-type cutting device. The original development again confirmed its characteristics and showed the possibility of destroying enemy obstacles. Nevertheless, by this time it became clear that there was simply no need for such equipment. Promising tracked vehicles did not need sophisticated wire cutting equipment, since they could destroy obstacles with only tracks.
Checking tracked vehicles and identifying their potential showed that the original engineering equipment no longer makes sense. With the help of tracks, promising armored vehicles could literally crush any obstacles, rendering the barbed wire unusable and giving the infantry the opportunity to go to enemy positions. The tank did not need any special equipment.
Based on the results of all tests, at the beginning of 1916, several fundamental decisions were made regarding the further development of military technology. The army initiated the creation of full-fledged projects of promising tanks, while at the same time abandoning some other developments. The planned reduction also included the Breton-Prétot Apparatus project, which implied the construction of individual engineering vehicles or the retrofitting of existing military equipment with special equipment. Work on the barbed wire cutter was curtailed and never resumed due to lack of prospects.
It should be noted that the project by Jules-Louis Breton and Preto was not the first or last attempt to create a specialized engineering vehicle designed to make passages in enemy wire entanglements. However, none of these developments has been brought to mass production and mass application. The emergence of completely new technology in the form of tanks on a tracked chassis made it possible to abandon such developments and focus on creating engineering vehicles of other classes that the army really needed.
