In 1954, the Soviet army ordered the automotive industry to develop a promising ultra-high cross-country vehicle suitable for use in the army as a multi-purpose vehicle. Having received such an order, the Moscow Automobile Plant im. Stalin set to work and soon created several experimental machines under the general name ZIS-E134. The most famous were the prototypes numbered 1 and 2. At the same time, there was no less interesting “Model No. 0”.
In accordance with the customer's requirements, the ZIS Special Design Bureau headed by V. A. Grachev was supposed to develop an all-wheel drive four-axle vehicle capable of moving both on the highway and over very rough terrain. As part of the first stage of the ZIS-E134 project, which led to the construction of Model No. 1, some original ideas were proposed. So, the project provided for the installation of wheel axles at the same distance from each other. It was also proposed to use large diameter wheels with adjustable tire pressure. In combination with a relatively complex transmission that provides power to all wheels, this made it possible to obtain sufficiently high characteristics of mobility and cross-country ability.
ZIS-E134 "Model No. 0" on testing
The prototype ZIS-E134 "Model No. 1" was built in August 1955, and a couple of months later it entered field tests. At that time, a number of solutions used in the project had not been sufficiently studied, which led to certain consequences. So, in the winter of 1955-56, it was decided at SKB ZIL to develop and build another prototype designed to test some aspects of the new chassis. First of all, he had to show the real possibilities of low-pressure wheels in the context of interaction with the surface and cross-country ability.
It is known that all the works of the Plant named after. Stalin's early four-axle all-terrain vehicles were carried out within the framework of one project called ZIS-E134. Prototypes built according to different versions of the project were designated as layouts and received their own numbers. For example, two four-axis mock-ups of 1955 and 1956 were numbered # 1 and # 2. An experimental vehicle for testing the chassis, built on new ideas, received the designation "Model No. 0".
The main task of the "zero" model was to check the chassis. In this regard, the development of the entire machine from scratch was not required. As a result, they decided to build it on the basis of an existing prototype of one of the latest models. For the restructuring, they chose one of the prototypes of a three-axle truck, which was later put into series under the name ZIL-157. In order to obtain special features, the car had to be seriously altered. The chassis has changed, and a new engine compartment has also appeared.
At the heart of the "Model No. 0" was a rectangular metal frame, borrowed without any special changes from the experienced ZIL-157. In front of the frame was a standard unit that combined the hood and the cab. It is curious that this device was created for the ZIS-151 truck and was used in several other projects with minimal changes. All "unnecessary" equipment was removed from the frame, which made it possible to bring the mass of the prototype to the required minimum. On the rear overhang of the frame, there is a new rectangular housing-casing for mounting the power unit.
To solve research problems, the new prototype had to show the minimum load on the ground. They decided to provide such an opportunity by unloading the front axle, for which the engine and part of the transmission elements were removed from their usual place under the hood. Now the gasoline engine and gearbox were housed in a special housing at the rear overhang of the frame. To further lighten the car, the hood cover was removed from it. Perhaps the project "Model No. 0" provided for the possibility of installing in place of the engine ballast, which changes the load on the front axle.
Despite the cardinal rearrangement, the rebuilt ZIL-157 prototype retained the same name in-line six-cylinder petrol engine with a volume of 5, 56 liters and a power of 109 hp. The power plant of the base car was connected to the fuel system, which included tanks with a total capacity of more than 210 liters.
As a further development of the ZIS-151 platform, the ZIL-157 and the prototype "Model No. 0" retained a relatively complex transmission that provided torque to all six wheels. At the same time, some new details had to be introduced into its composition. The engine was located at the rear of the car, directly in front of it was the gearbox. To connect them with other elements of the transmission, an inclined propeller shaft was used, which passed over the frame.
A mechanical five-speed gearbox was used. Then, using a long inclined intermediate shaft, the power was transmitted to the transfer case. The latter was intended to distribute power to three other driveshafts. One of them went to the front axle, the second to the middle one. The rear axle was driven through two shafts: the first went from the transfer case to the intermediate bearing assembly on the middle axle, and the second was connected directly to the rear axle.
The ZIL-157 truck had a three-axle chassis with a 6x6 wheel arrangement. Split axles were installed on leaf springs. In this case, the front axle had a pair of its own springs, and the two rear axles formed a bogie with common elastic elements. The front axle was steered. A characteristic feature of the truck was the absence of any amplifier in the steering system.
The car received wheels measuring 12.00-18. ZIL-157 was the first Soviet truck equipped with a centralized tire pressure regulation system. The devices associated with the onboard compressor allowed the pressure to be varied within a fairly wide range. Normal pressure was set at 2.8 kg / cm 2. When driving on soils with a low bearing capacity, it could be dropped to 0.7 kg / cm 2. However, this led to a reduction in the maximum permissible travel speed and to increased tire wear.
"Model No. 0" retained the metal cabin of the base truck. It had three seats for the crew, as well as a set of instruments and controls. In general, the layout and equipment of the cockpit remained the same, however, some modifications were required for individual devices. So, the transfer of the gearbox to the rear of the car demanded to equip it with new means of remote control. The rest of the cabin remained the same.
The need to lighten the vehicle and the installation of a new engine compartment led to the fact that the experienced ZIS-E134 "Model No. 0" did not receive any cargo platform. The central part of the frame, located between the cab and the power unit, remained open.
Despite the noticeable redesign of the design, the main weight and overall characteristics of the prototype corresponded to the parameters of the experimental ZIL-157. The length of the vehicle still did not exceed 6, 7 m, the width was slightly more than 2, 3 m. The height was less than 2, 4 m. The curb weight of the prototype was at the level of 5, 5-5, 6 tons. At the same time, there was no need to talk about the carrying capacity, since there was no cargo area on the car, and the tasks of the project were not directly related to the transportation of goods. The estimated maximum speed of the car on the highway reached 60 km / h, the cruising range was at least 500 km.
The aim of the ZIS-E134 "Model No. 0" project was to check the operation of the undercarriage with a reduced specific pressure on the supporting surface. It was to reduce this parameter that it was decided to move the engine and gearbox back. In addition, the tire pressure was kept low, which also affected the overall parameters of the front axle. Due to the special arrangement of the units, most of the weight of the machine had to fall on the rear bogie. It was possible to maintain normal pressure in its wheels. Thus, the front axle of the car actually turned out to be equipment for the experiment, and the two rear axles were auxiliary equipment that provided the necessary conditions.
ZIL-157, which became the basis for "Model No. 0"
At the very beginning of 1956, the "zero" model of the all-terrain vehicle, built as part of the large ZIS-E134 project, first entered the test range for testing in real conditions. It was quickly established that the car would not be able to show high performance, and in some cases its operation would be associated with the most serious problems. Similar features of the prototype were associated precisely with the specific characteristics of the chassis.
Already at the first stages of the run-in it was established that the "Model No. 0" with a reduced pressure of the front axle on the surface can normally drive only on good roads, while going off-road quickly led to problems. For example, while driving on a snowy polygon, the front axle did not show the desired characteristics. She did not provide sufficient traction with the ground, and sometimes even rose above it. There was a serious deterioration in handling associated with the same lack of grip. In addition, the front wheels in some cases acted as a dozer blade and collected a pile of snow in front of them. The wheels could not overcome such “in-house” obstacles, which caused the car to stop.
Tests of the ZIS-E134 "Model No. 0" did not last too long and ended with negative results. Practice has shown that the proposed design of the undercarriage may have some positive features, however, along with them, the most serious disadvantages appear. The proposed and applied ideas had a certain potential, but for its full implementation, other chassis designs were required. Further operation of the prototype in the existing configuration did not make sense.
With the help of "Model No. 0" Special Design Bureau of the Plant named after Stalin was able to collect important information about the features of the operation and behavior of low-pressure wheels, characterized by minimal pressure on the supporting surface. This information was taken into account in further work in the field of ultra-high cross-country vehicles and the creation of new projects. So, only within the ZIS-E134 family, two more prototypes were built after the "zero" model. In other projects, similar solutions were also used later.
The further fate of the prototype No. 0 is not known for certain. It was built on the basis of the existing prototype chassis of a promising truck and, apparently, after the completion of the tests, it again went for alteration. It could be returned to conformity with the original design or converted into a prototype of a new type. In the fifties, the Plant. Stalin, later renamed the Plant. Likhachev was actively involved in the theme of trucks of different classes, and would hardly have allowed the equipment to stand idle.
The prototype ZIS-E134 "Model No. 0" was built in order to test some concepts suitable for use in full-fledged projects of automotive technology. During the tests, it was found that such ideas have a certain potential, but the existing machine could not reveal it. This meant that SKB ZIL and other organizations of the automotive industry should continue research work, including the construction of new experimental machines. The development of the ZIS-E134 project continued and soon led to the appearance of another prototype.
