Since 1966, a special design bureau of the plant. I. A. Likhachev dealt with the topic of all-terrain vehicles with the so-called. rotary screw propeller. The first experiments in this area, carried out using the original prototype, showed all the main features of the unusual chassis. Now it was possible to start developing a full-size machine suitable for use in real conditions. The new snow and swamp-going vehicle with a screw chassis was named ZIL-4904 and PES-3.
The first machine-auger from SKB ZIL was a sample called ShN-67, which was later redesigned and renamed ShN-68. For several seasons, the experienced all-terrain vehicle has been tested in different regions and conditions, ensuring the collection of a large amount of data on the operation of a non-standard propulsion device. Soon a special stand was built at the Moscow plant, with the help of which it was supposed to work out various configurations of rotary-screw systems, without resorting to rebuilding the existing prototype. Research work also yielded the desired results, and it was possible to start developing a new all-terrain vehicle.
Snow and swamp-going vehicle ZIL-4904 / PES-3 on a transport trailer. Photo of the State Military Technical Museum / gvtm.ru
At the end of the sixties, specialists from SKB ZIL, headed by V. A. Grachev continued to work on search and evacuation installations for the space industry. The cosmonautics needed ultra-high cross-country vehicles capable of reaching the most inaccessible areas and taking out cosmonauts with a descent vehicle. By this time, the PES-1 all-terrain vehicle was created and accepted for supply, but the work did not stop. In the early seventies, the development of two new projects began at once: a wheeled all-terrain vehicle PES-2 and a screw PES-3.
Special requirements were imposed on the evacuation technique in terms of cross-country ability, and therefore at a certain moment there was a proposal to build a machine with a rotary screw propeller. By analogy with its predecessors, this sample was designated as PES-3. He also had the factory designation ZIL-4904, which revealed some of the features of the project. The numbers in this index indicated that the all-terrain vehicle belonged to the class of special equipment with a gross weight of 8 to 14 tons. However, the names used did not reflect the most interesting features of the project.
All-terrain vehicle on tests, corresponding to the PES-3A project. Photo "Equipment and weapons"
The design continued until the beginning of 1972, after which the construction of the future PES-3 all-terrain vehicle began at the ZIL pilot production facility. For a certain simplification of construction and subsequent operation, it was proposed to use already worked out ideas and technologies. In addition, ready-made assemblies were widely used. In particular, they used power units from the serial ZIL-135L chassis and other available products.
Based on the experience of previous projects, the car was built on the basis of a frame welded from metal profiles. A cladding made of steel and fiberglass was mounted on the frame. The entire lower sealed displacement part of the hull received a metal sheathing. Plastic was used only as part of the upper hull assemblies. The lower steel part of the body had a rather complex shape, formed by several intersecting planes. She received a polygonal cross-section with a central unit, on the sides of which the propeller rotors were supposed to be. The upper units of the metal hull formed a large platform-deck.
Power plant and transmission from the PES-3A project. Drawing "Equipment and weapons"
In front of the vehicle there was a large fiberglass cockpit. Immediately behind it, a large cargo area was provided, suitable for placing a payload or an additional module, such as a passenger cabin. The entire load was to be placed only on the site. The internal volumes of the hull were given only for the power plant and transmission devices. Some other units were also present, such as fuel tanks with a total capacity of 1200 liters.
In the rear of the hull, below the roof-deck, flywheels forward were placed two gasoline engines ZIL-385 with a capacity of 180 hp each. In front of them were automatic hydromechanical transmissions. Such power units in the form of an engine and transmission were borrowed from the serial ZIL-135L without any special modifications. In front of the gears there was a summing gear connected to them by means of a pair of cardan shafts. A five-shaft gearbox with a reverse function provided power to a longitudinal propeller shaft that passed between the engines. In the rear of the car were the main gear, a pair of dry friction side clutches and band brakes.
Onboard transmissions provided the output of torque to the bushings of the rotor of the chassis. The latter were located in the rear of the hull and, with the help of racks, were carried at a certain distance from the sides of the hull. The propulsion unit was driven only from the rear.
Auger on the water. Photo Tehnorussia.ru
Based on the research results, using a special stand, the optimal appearance of the rotary-screw propeller was formed. The PES-3 all-terrain vehicle was planned to be equipped with a pair of screw rotors 5, 99 m long with a main cylinder diameter of 1, 2 m. The cylindrical body and conical ends of the screw were made of AMg-6 alloy. On the outer surface of the body, spiral lugs of a triangular cross section with a height of 150 mm were fixed. The cylinder had three spirals with an angle of installation of 34 °.
The front end of the auger was fixed on a fixed base under the cockpit. To facilitate movement over rough terrain, such a mount was covered with an inclined flap-ski. Rear supports with shafts and transmission gearboxes were located openly in the stern.
The all-terrain vehicle was equipped with a three-seater cabin with large glazing. Access to the crew's workplaces was provided by a pair of side doors. The relatively high height of the car and the absence of any footrests made it difficult to land to some extent. However, in this respect, the ZIL-4904 auger was little different from other equipment of a similar purpose.
Tests on the water, view of the stern. Photo "Equipment and weapons"
The driver's control room had a dashboard with a set of dial gauges, buttons and toggle switches. The operation of engines, hydromechanical gears and transmissions was controlled using a set of levers and pedals resembling the equipment of conventional tracked vehicles.
The basic ultra-high cross-country chassis with an unusual propeller was rather large. The length of the PES-3 reached 8275 mm, the width was 3.2 m. The height along the roof of the cab was 3 m. On a hard surface, the ground clearance reached a record 1.1 m. The front overhang angle was 30 °, the rear - 70 °. The curb weight was set at 7 tons. Together with a payload of up to 2.5 tons, the total mass of the vehicle slightly exceeded 10.1 tons. According to calculations, on snow or mud the auger could reach speeds of up to 15-17 km / h. The maximum speed on the water was determined at 8-10 km / h.
ZIL-4904 after restructuring according to the PES-3B project. Photo Tehnorussia.ru
During the tests of the ShN-67/68 prototype, it was found that the rotary-screw propeller cannot be used on hard surfaces. On asphalt or concrete, metal lugs, taking on the entire mass of the car, quickly wore out and lost their characteristics. In this regard, within the framework of the new project ZIL-4904, a special transporter was developed for transporting an all-terrain vehicle on roads.
It was proposed to transport the PES-3 car on a special trailer of sufficient dimensions. An axle with two wheels equipped with “all-terrain” tires was installed on the trailer in front of the platform of the required dimensions. A two-axle bogie with similar wheels was placed behind the site. A trailer in conjunction with a ZIL-130 truck could ensure the delivery of a prototype to the test site. Despite its exclusively supporting role, the special trailer made a significant contribution to the testing and the project as a whole.
Based on the experience of operating existing search and evacuation installations, it was proposed to create two main modifications of a promising all-terrain vehicle. So, a car called PES-3A was intended to transport rescuers, astronauts and some cargo or equipment. The descent vehicle, in turn, had to be taken out on the lodgment of the PES-3B all-terrain vehicle. There was also a proposal to equip both machines with a rigid coupling, due to which they could be connected into a system with an additional increased cross-country characteristics.
Transmission diagram from the PES-3B project. Drawing "Equipment and weapons"
At the beginning of 1972, after completing the design work, SKB ZIL launched the assembly of an experienced auger. The car was built according to the PES-3A project and was supposed to carry the passenger compartment. A fiberglass cabin was installed behind the cockpit, which rose almost half a meter above it. The salon took up about half the length of the hull. An additional box-type casing with volumes for the transportation of equipment and property was provided behind the cabin. The passenger cabin had several windows in the front wall and sides. Landing was carried out through a small rear hatch. Inside the cabin, four seats were provided for passengers. There were also lockers and other volumes for a variety of rescue and medical equipment.
April 30, 1972 Plant them. Likhachev completed the construction of a prototype vehicle in the PES-3A version. Until mid-May, the assembly of a special trailer continued, and only after its appearance, the all-terrain vehicle could be sent for testing. The first checks were carried out on the water. The ponds of the fish factory "Nara" became the testing site. For about two hours the auger was floating at high speed, after which the main gear overheated. Having disassembled it, the experts found that several parts had collapsed due to lack of lubrication. Repair and revision of the lubrication means was required.
Transportation of PES-3B on a special trailer. Photo "Equipment and weapons"
In June, a new stage of testing began, during which the ZIL-4904, among other things, was compared with other samples of special equipment. The maximum speed of the all-terrain vehicle on the water exceeded 10 km / h. With a load of 2.5 tons, it accelerated to 9, 25 km / h. In the swamp, the speed without load and with load was 7, 25 and 7, 1 km / h, respectively. Once again it was confirmed that the augers PES-3 and ShN-68 are able to move along the so-called. raft, while for tracked vehicles it turns out to be insurmountable.
At the same time, it was found that under certain conditions the rotary-screw propeller shows insufficient maneuverability on soft surfaces. So, on floating vegetation, he, poorly responding to the driver's commands, showed a tendency to turn towards the least resistance. In some cases, this feature of the machine made it difficult to maneuver immediately after going ashore.
By the beginning of the fall of 1972, SKB ZIL completed tests of an unusual machine and began to refine the existing project, taking into account the accumulated experience. Tests have shown that the existing transmission design is overly complex and needs to be improved. Also required some changes to the power plant and control systems. Finally, in the course of the future restructuring, the ZIL-4904 all-terrain vehicle was proposed to be converted into a cargo version of the PES-3B.
Auger PES-3B (in the background) on joint trials. Photo "Equipment and weapons"
Power units in the form of engines and hydromechanical transmissions were turned backwards. The summing reducer was removed. Now the drive shafts departed from the GMP, connected to their own final drives. In the new version of the project, each engine was connected only with its own rotor-auger. As a result, the controls had to be changed. The engine control pedals were gone from the cab, instead of which the existing levers should now be used. Each of the driver's two levers was connected to the engine throttle and the clutch of its side. Moving the lever forward would increase the engine speed. Pulling the lever towards himself, the driver reduced the speed and braked the auger.
Instead of the existing passenger compartment, a simple side body with the possibility of installing an awning was mounted on the hull. In the future, the PES-3B cargo all-terrain vehicle was to receive a hydraulic crane and a cradle to accommodate the spacecraft. As far as is known, the prototype did not have such equipment. Probably, it could have been installed later, before the next stage of testing.
For a number of reasons, the process of finalizing the existing project was noticeably delayed. The tests were resumed only in mid-January 1978 - a few years after the completion of the checks of the "basic" PES-3A. The ponds of the Nara combine again became the testing ground. Before the beginning of winter, the water was drained from the ponds, and a little later they were filled with snow. Thus, the track for the all-terrain vehicle was a peat area with loose snow up to 550 mm deep.
Auger after being sent to the museum. Photo Kolesa.ru
During the tests, the all-terrain vehicle moved on the snow cover, and also climbed the dams between the ponds and descended from them. The movement was carried out in a straight line, with turns and sideways. The new transmission has been shown to be capable of varying turning radii, down to the minimum. In some cases, however, slippage of the external auger was observed. There were no such problems on corners with a large radius. While driving in the snow, the rotors of the PES-3B all-terrain vehicle buried about 500 mm. If the snow cover was thicker than half a meter, there were no problems. Driving in thinner snow with relatively hard ground underneath resulted in some abrasion of the lugs.
The promising PES-3B was tested in conjunction with other vehicles with other chassis options. Depending on the characteristics of the track, the auger could show advantages over "competitors", demonstrate similar results or lose to them. So, on mud or shallow snow, the GAZ-71 tracked transporter showed the best speed indicators, but on a swamp or raft, the ZIL-4904 turned out to be the undisputed leader. It is curious that in all cases the auger-driven snow and swamp-going vehicle demonstrated the highest fuel consumption - up to 80 l / h.
The special vehicle PES-3 has been tested in two configurations and has shown its capabilities in a variety of conditions when solving various tasks. A large amount of data was collected, which made it possible to conduct an analysis and make a final decision on the further fate of an interesting development. The authors of the project and representatives of the air force, who in the future might have to operate such equipment, decided to abandon the further development of the existing project.
Left auger, front view. Photo Kolesa.ru
Indeed, the ZIL-4904 showed the highest characteristics of mobility and maneuverability in the most difficult terrains and left all competitors far behind. He could get to remote areas and take astronauts out of places where other all-terrain vehicles of existing types could not get. However, the vehicle had characteristic drawbacks that made it difficult to use it as a search and evacuation unit.
The PES-3 all-terrain vehicle had a length of more than 8 m and a width of more than 3 m, and also weighed almost 7 tons. For its transportation on public roads, a special trailer was required, and transportation by aircraft or helicopters of military transport aviation was excluded due to its excessive dimensions. Thus, the search and rescue service of the Air Force, using the existing and promising models of equipment, could not deliver the all-terrain vehicle to the place of work in the shortest possible time. The existing machines of the PES-1 family, in contrast to the auger, had sufficient mobility and therefore could not give way to the new PES-3. It should be noted that the PES-2 wheeled all-terrain vehicle faced similar problems a few years earlier. It could carry both rescuers with astronauts and the descent vehicle, but at the same time it was too large and heavy to be transported by air.
Based on the test results of the PES-3 snow and swamp-going vehicle, the customer and the developer made several main conclusions. They recognized that such a technique really has great prospects and may be of interest in the context of exploratory work. At the same time, it was established that a new model of this kind - if it is to be developed - should be created taking into account the capabilities of military transport aviation.
Car on a trailer, rear view. Photo Kolesa.ru
Soon after the completion of the ZIL-4904 tests, a decision was made to create a new all-terrain vehicle with a rotary screw propeller that meets the new requirements. The result of new work in a few years was the ZIL-2906 and ZIL-29061 vehicles. This equipment, having passed all the required checks, was accepted for supply as part of the PEC-490 search and evacuation complex. Due to its small dimensions and weight, the new auger vehicle could be transported not only by airplanes or helicopters, but also by the ZIL-4906 wheeled all-terrain vehicle with a crane and a cradle. The ZIL-2906 was supposed to get to the place of work at the site of the cargo all-terrain vehicle.
The decision to abandon the ZIL-4904 / PES-3 all-terrain vehicle was made at the end of 1978. The most interesting, but unpromising car, together with a special transport trailer, was returned to Moscow to the manufacturing plant. She stood idle for years and then went to the museum. Currently, the auger vehicle in the configuration of a truck is located in the State Military Technical Museum (Ivanovskoye village, Moscow region), where it is demonstrated along with a number of other developments of SKB ZIL.
The PES-3 screw-rotor snow and swamp vehicle was created taking into account the future practical use in two roles at once. Tests have shown that this machine is capable of solving the assigned tasks, but at the same time it has a number of characteristic problems that interfere with full-fledged work. It was proposed to correct the identified shortcomings within the framework of a new project. Taking into account the accumulated experience, the ZIL-2906 and ZIL-29061 all-terrain vehicles were created. They entered the service and are still in operation, ensuring the timely evacuation of the landed cosmonauts.
