Since the mid-twenties, the Yaroslavl State Automobile Plant No. 3 has been developing new trucks and has consistently developed a number of vehicles with different characteristics. At the end of the decade, the Y-5 car was presented and put into series, which became the progenitor of a whole family of automotive technology. It was on its basis that the YAG-10 three-axle truck was soon developed. This car was not produced in a particularly large series, but still took an important place in the history of the Soviet automotive industry. It was the first model with a 6x4 wheel arrangement of domestic development and our first car of the eight-ton class.
The history of domestic three-axle trucks began at the end of the twenties, when the command of the Red Army made demands to create a promising heavy-duty truck with a 6x4 wheel arrangement. In 1929, the Scientific Automotive Institute and a number of automobile factories began to study new topics and prepare for the creation of new models of technology. Soon, several promising projects were created, and then an experienced technique came out for testing. The Yaroslavl YAG-10 truck was the first to go to the test site.
Truck YAG-10. Photo Bronetehnika.narod.ru
YAGAZ engineers, interacting with US, were able to quickly find the best option for creating a promising truck. The production car I-5 showed very high performance and therefore could become the basis for a three-axle vehicle. In the shortest possible time, the design bureau of the enterprise revised the existing project and received the necessary appearance of the equipment with the required parameters. When developing a new car, it was decided to use the maximum number of ready-made units of existing vehicles, supplemented with new units. It is noteworthy that the bulk of the new parts were borrowed from foreign cars.
The new truck, created on the basis of the serial Y-5, later received the official designation YAG-10. The development of the project was completed at the very beginning of the thirties, when YAGAZ switched to a new designation system. As a result, the letters YAG - "Yaroslavl truck" appeared in the name of the car. The number indicated the serial number of the project.
The main element of the YAG-10 truck is a reinforced frame made of channels. Due to the increased loads, its spars were reinforced. On their rear part on top, above the wheeled cart, additional channels were placed, placed with a shift back. This made it possible to increase the length of the frame, but led to an increase in the installation height of the loading platform. Also, new cross members appeared on the frame, providing the necessary rigidity. The general arrangement of the units on the frame, with the exception of the new rear bogie, was borrowed from previous projects.
The Ya-5 machine is the basis for the YaG-10. Photo Wikimedia Commons
The new YAG-10 "inherited" the American-made Hercules-YXC-B carburetor engine with a capacity of 93.5 hp from the base Ya-5. The four-speed manual transmission Brown-Lipe-554 remained in its place. Two propeller shafts that drive the rear drive axles were proposed to be borrowed from the American Moreland truck. It is noteworthy that the experimental YAG-10 used these parts, taken directly from an imported vehicle. Later, the plant mastered the production of copied units.
The front steered axle for the YAG-10 was borrowed without changes from the existing truck. It was equipped with a not very successful steering mechanism, as a result of which a large diameter steering wheel was needed, on which significant loads were still maintained. Subsequently, this problem was solved with the help of new mechanisms.
The rear bogie with two driving axles was organized according to the WD scheme, which at that time was actively used by foreign automakers. Balance beams were attached directly to the car frame, at the ends of which the centers of the leaf springs were placed. The ends of the springs were connected to the bridge stockings through shoes with ball bearings. Also in such a suspension there were longitudinal elements that ensured the rigidity of the structure and the transfer of loads to the frame. Some of the parts for the YAG-10 rear bogie were developed on the basis of the Moreland units.
YAG-10, view to the starboard side. Photo Bronetehnika.narod.ru
The rear axle of the YaG-10 was a corresponding part of the Ya-5 machine. The second axle was developed on its basis and included its own gear reducer. The engine torque from the gearbox was fed to the front axle of the bogie, from which a second shaft of small length departed. The shafts provided large angles of misalignment, which, in combination with the suspension design, should have provided high cross-country ability in difficult terrain.
Both rear axles were gable. Unlike the I-5, a central brake associated with the transmission was now used. There was a foot brake with a vacuum booster taken from a previous project. At the same time, the braking system was redesigned. In particular, the rear axles now used a two-pad system instead of the previous four-pad system.
The presence of a two-axle rear bogie gave the car new possibilities. So, the designers have provided for the use of track chains of the Overroll type. If necessary, they could be installed on the rear wheels, increasing the area of contact with the ground, and with it the cross-country ability.
YAG-10 was equipped with a Hercules engine and therefore could retain the existing hood. Instead of the front wall of the engine compartment, there was a cellular radiator of the existing model, and the side and rear of the power unit was covered with metal panels. For servicing, hinged side flaps with louvers slots were intended. The fixed cover had a pair of rectangular hatches.
Experienced eight-horse at the factory. Photo Bronetehnika.narod.ru
The car has retained the same cabin of a mixed design that could accommodate three people. The layout, ergonomics, equipment and design of the glazing have not changed. This, first of all, was facilitated by the use of an already mastered power unit. As in previous projects, there was a 177 liter fuel tank under the driver and passengers seat.
The lengthening of the frame made it possible to slightly increase the dimensions and volume of the cargo platform. Its design, however, remains generally the same. The hinged sides were hinged to a horizontal plate made of boards. An important feature of the YAG-10 was the increase in loading height. Due to the presence of a pair of additional channels on the frame, the body was raised, which could complicate loading and unloading. Also, the modified frame could complicate the construction of special equipment based on the existing chassis.
The three-axle YAG-10 truck had a total length of 6, 97 m - noticeably more than the previous YAGAZ samples. Width was 2, 47 m, height - 2, 55 m. The curb weight of the vehicle increased by almost 2 tons and amounted to 6800 kg. The increase and weight of the truck paid off. The maximum carrying capacity (for work on highways) reached 8 tons - this was a record among Soviet cars at that time. When working on unpaved roads, the payload was limited to 5 tons. The increase in weight characteristics led to a decrease in power density, and the maximum speed of the YAG-10 was only 42 km / h. Fuel consumption on the highway exceeded 60 liters per 100 km.
On tracks and polygons
The first prototype YaG-10 was built by November 7, 1931, and a few days later went to Moscow on its own. A few days later, the car entered testing. To save time, several machines were tested at the same time. The Yaroslavl truck was to be compared with foreign three-axle models. Already in the first test drives, some shortcomings were identified. There were also minor breakdowns.
Bench test of suspension travels. Photo Bronetehnika.narod.ru
Tests of three cars, including the first YAG-10, were carried out on the highway of the Moscow region on the streets of Moscow. The trucks were loaded in different ways and guided along established routes of varying difficulty and length. In addition, tests were carried out for cross-country ability, stability, etc. In general, the specialists were able to carry out comparative tests and establish the ratio of all the main characteristics. However, for two weeks of testing, it was not possible to determine only the real reliability of the equipment.
Based on the results of the first stage of testing, NAMI / NATI determined a list of necessary improvements. The new eight-ton truck, in terms of its main characteristics, did not differ much from the foreign models that participated in the comparison. To improve the technical characteristics and reliability, NATI recommended making changes to the design of the transmission and suspension of the rear bogie.
The requirements of the Scientific Institute were taken into account, but not all of its proposals reached implementation. So, in parallel with the YAG-10, another NATI truck was tested. He had a main gear based on a worm, which, according to the test results, was recommended for use on a Yaroslavl car. However, soon this unit almost failed the tests, and the YAG-10 was rejected from such a revision. As a result, YAGAZ improved the system based on gears and received the required characteristics.
YAG-10 with chains "Overoll." Photo Denisovets.ru
The design improvements did not take much time, and at the beginning of 1932 the first batch of serial trucks was assembled. On February 8, five serial YAG-10s were brought to Moscow and demonstrated to the country's leadership. People's Commissar for Military and Naval Affairs K. E. Voroshilov familiarized himself with this technique and warmly praised it. In addition, he pointed out the importance of three-axle trucks for the army and the national economy. Voroshilov congratulated the YAGAZ designers on their successes and expressed the hope that the new vehicles would go into large-scale production as soon as possible and get into the troops.
After the first demonstration to the country's leadership, the YAG-10 returned to fine-tuning. Improvement of individual units was carried out, and minor shortcomings were eliminated. In addition, there have been major innovations. So, shortly before the launch of a full-fledged series, a demultiplier was introduced into the transmission, which made it possible to increase traction by 40%, regardless of the gear. This gave a serious increase in mobility and maneuverability.
Machine in series
In mid-1932, the three-axle eight-ton YAG-10 went into full-scale production. According to estimates of that time, YAGAZ was supposed to produce at least a hundred of these machines annually. However, limited production capacity did not allow these plans to be fulfilled. In addition, dependence on imported engines affected the pace of construction. By the time the production was started, full-scale deliveries of Hercules engines had ceased, and this began to threaten the new project.
Tests of the truck in a half-track configuration. Photo Bronetehnika.narod.ru
The military department wanted to continue the production of trucks and put pressure on the leadership of the automotive industry. Almost all available Hercules-YXC-B engines and related equipment were reserved for the YAG-10. This led to a halt in the production of two-axle Y-5 vehicles and the subsequent appearance of a new YAG-3 truck. The available stock of imported units made it possible to continue the production of YAG-10 until 1934-35. Using this stock, 35 vehicles were assembled in 1932, 78 in 1933, and in the next two years YAGAZ delivered 50 and 15 vehicles, respectively.
Nevertheless, after exhausting the stock of motors, production did not stop. Several dozen trucks were built annually until 1939. The new peak of production fell on 1936 - 75 cars. The last 4 copies were built in 1940. Engines for these machines were purchased under separate contracts in relatively small quantities. At the same time, curious processes took place. Thus, the Azneft organization needed powerful trucks, but YAGAZ could not supply them. To solve this problem, oilmen independently purchased the necessary components from the United States and sent them to Yaroslavl.
In 1936, the YAG-10M project was developed. It provided for the use of a new ZIS-16 engine and a different transmission. In the near future, such a truck was supposed to go into series and solve the problem of motors. However, only 10 prototypes were built. The reasons for this are commonplace: the Plant named after. Stalin was able to satisfy only his own needs and could not supply engines to other enterprises.
Self-propelled anti-aircraft guns based on YAG-10 at the parade in Moscow. Photo Bronetehnika.narod.ru
Taking into account the needs of customers, YAGAZ produced YAG-10 vehicles in the configuration of an onboard truck and chassis for the installation of special equipment. Until 1940, inclusive, the enterprise collected 158 trucks and 165 pieces of equipment for re-equipment.
Operation and revision
Trucks and chassis YAG-10 were supplied mainly to the Red Army. Onboard trucks were used as transport and artillery tractors. The car was praised for its high carrying capacity and its ability to tow heavy trailers - primarily large-caliber guns. In some situations, the cross-country ability was insufficient, but the carrying capacity fully compensated for these shortcomings.
A number of trucks and chassis were converted into original self-propelled anti-aircraft guns. A new metal platform with jacks, a machine tool and a 76-mm anti-aircraft gun mod. 1931 3-K. Such a ZSU could, in a minimum time, go to a given area and quickly deploy. Unlike towed guns, a gun on a cargo chassis could start firing almost immediately after arriving at a position. Anti-aircraft vehicles based on the YaG-10 remained in service until 1941-42 and managed to take part in the Great Patriotic War, providing air defense for some objects.
One of the variants of a tank truck on the YAG-10 chassis. Photo Scaleforum.ru
Also in the army, cars with box bodies were used. Such equipment carried radio stations, performed the functions of command and staff vehicles, transported the wounded or solved other tasks.
YAG-10 found application in the national economy. So, on the basis of a truck chassis, tank trucks for various purposes were built. Such vehicles transported fuel and water, and could also carry special equipment - fire pumps, etc. Among the fire trucks based on the Yaroslavl chassis, the self-propelled auto pump NATI-YAG-10 is of particular interest. In 1934, the Azneft organization ordered the development of a fire engine with a pump, capable of extinguishing complex fires in the fields. It was for the construction of such equipment that the oilmen independently purchased the necessary engines abroad.
The fire-fighting option for "Azneft" received an open cabin, behind which there were a cistern for 4.5 tons of water and two pumps. The first was driven by the car's own engine, and for the second, a separate motor of the Hercules-YXC-B type was provided. The latter was in the characteristic aft hood. According to various sources, several such machines were sent to the Azerbaijan SSR.
A tank truck with a pump designed for Azneft. Rear view, foreground - auxiliary motor for the pump. Photo Autowp.ru
Despite the supply of equipment to enterprises of the national economy, the main operator of eight-ton vehicles of the YAG-10 type was the Red Army. Almost all of this equipment remained in service at the beginning of the Great Patriotic War, and suffered serious losses in the first months. In the future, the active use of machines led to increased wear and known results. No later than the mid-forties, all or almost all of the YAG-10 were lost or written off after the resource was used up. Unfortunately, not a single such car has survived.
First of its kind
Since the end of the twenties, the command of the Red Army demanded to create their own three-axle trucks with a high carrying capacity. This problem was solved by a number of domestic automotive enterprises, but the Yaroslavl State Automobile Plant was the first to cope with it. His YAG-10 was the first to be tested and one of the first to enter the series.
Nevertheless, the Yaroslavl project depended on the supply of foreign components, which led to negative consequences. The production of YAG-10 machines lasted for eight years, but was of an episodic nature and even by the standards of that time it was small-scale. For all the time, it was possible to build a little more than 300 trucks and chassis for different needs. As a result, other domestic three-axle vehicles of that time were inferior to the YAG-10 in terms of carrying capacity, but outnumbered. The first domestic three-axle eight-ton trucks may not have been able to realize their full potential, but still had a serious impact on the development of the automotive industry and took their place in its history.