Better without differential
The first part of the material dealt with the search layouts of the ZIS-E134, as a result of which the concept of the future four-axle truck was chosen. During the tests on February 8, 1957, the opponents of the floating model No. 2 were the serial BTR-152V, ZIL-157 and the experimental ZIL-E152V armored personnel carrier. The last car was three-axle with a uniform axle distribution over the body and was equipped with large diameter wheels. This armored vehicle was also developed at SKB Grachev and was a representative of the second branch of the bureau's engineering projects - three-axle off-road vehicles. The most famous serial models of this scheme were machines of the "Blue Bird" family, used to evacuate cosmonauts who landed (splashed down).
But back to the tests in February 1957. BTR-152V and ZIL-157, as expected, were eliminated at the stage of overcoming a full-profile trench, which Grachev's cars easily passed. However, the ZIS-E134 got stuck in a much wider trench with a cell for a fighter, but an experienced E152V armored personnel carrier was able to drive in and out in front and back. But problems with the reliability of the CV joints of the middle axle did not allow the armored personnel carrier to successfully complete the tests. The four-axle vehicle was redesigned: the front and buildings' bridge was removed from the center by more than a meter, leaving the 2nd and 3rd bridges untouched. The last bridge had to be made manageable. Such an elongated vehicle was able to overcome already anti-tank ditches up to 2.5 meters wide. It is interesting that among military engineers there is such a term as entrenchment, with which everything was in order with the new machine. Developers of SKB, when working on the model No. 2 of the ZIS-E134, came up with the idea to do without differentials altogether, installing two motors on SUVs, each of which drove the wheels of its side. It was also understood that four axles are enough for machines of this standard size.
For the first time, a similar scheme with two motors on a four-axle chassis was tested by SKB Grachev on a floating ZIL-135, in which it is very difficult to recognize a familiar missile carrier. Its development, according to some reports, was initiated by SKB with the aim of avoiding direct competition with the products of SKB-1 of the Minsk Automobile Plant. As mentioned in the first part of the material, Grachev's team lost the competition with the heavier MAZ-535. Then the honor of ZIL was defended by the medium tractor ZIL-134, but the unreliable V12 engine did not allow it to compete on equal terms with MAZ equipped with tank diesel engines. The floating ZIL-135 became the ancestor of the so-called Grachevsky school of designing wheeled vehicles, whose followers, at the beginning of the 21st century, built vehicles according to these patterns. I must say that the twin-engine scheme is not the know-how of Grachev's team - such a layout solution was resorted to in wartime.
Light tank T-70, self-propelled gun Su-76M, experienced tractors AT-8 and AT-14 were equipped with two engines, but not from a good life. Motor hunger, unfortunately, has always been a sign of the domestic automotive industry (and not only it), therefore, it was necessary to put pairwise weak engines on heavy cars. So in the SKB of the Moscow Automobile Plant, for lack of a better one, it was necessary to install a pair of experimental carburetor ZIL-120VK, developed on the basis of a 6-cylinder ZIL-120. The motors were installed on the ZIL-135 amphibious transport vehicle, which was built on October 3, 1958 under an agreement with the Ministry of Defense. The amphibian, one of a kind and released in a single copy, is called index 135 without any letter clarifications. All the other 135 cars of the Moscow Automobile Plant necessarily had letters, or even more than one. A characteristic feature, in addition to the twin-engine layout and the original steering scheme, were the wheels rigidly fixed to the chassis. The lack of suspension, as conceived by Grachev, was supposed to level the low-pressure tires, of course, equipped with pumping. Also, the advantages of a car without a suspension include a low height - an average ZIL-134 artillery tractor of similar dimensions with a suspension was 250 mm higher than the ZIL-135. The body did not need wheel arches designed for suspension travel. On tests, such a reckless technical solution left the car sideways - road irregularities up to 25 mm high at speeds of 17-22 km / h caused dangerous resonance vibrations of the body. And if you accelerate faster on bumps about 100 mm in height, then a branded galloping appeared, which could be thrown out of the way.
During the development of the machine, the main purpose of its creation is still unclear. The amphibious transport vehicle, obviously, meant the delivery of fighters from the landing ships to the shore, but in parallel in Gorky, the development of the BTR-60 was already underway, which was protected by armor and also knew how to swim. The car also did not resemble a ballast tractor as an analogue of the MAZ-535: it did not have enough power or mass, and it did not need to swim. The ZIL-135 was not suitable for the role of a massive army amphibious truck due to its excessive complexity and high cost. It is also possible that the four-axle vehicle could be developed as a replacement for the aging amphibian ZIL-485A. At the same time, the novelty surpassed it twice in terms of carrying capacity and cross-country ability. Obviously, the SKB did not fully understand the tactical purpose of the floating boat. Be that as it may, the flat seaworthy bottom, coupled with a large ground clearance, allowed the ZIL-135 to move confidently through snow up to 0.6 meters deep. By the way, the Soviet design bureaus returned to the concept of a mass floating vehicle a little later - in Miass they worked on secret Urals with displacement bodies and foam floats.
A little about the technical intricacies of the amphibian. The amphibious transmission was very complex: two hydrodynamic gears (each included a ZIL-111 torque converter, a 2-stage demultiplier and a 3-speed planetary gearbox), two transfer cases, eight final drives and eight wheel gearboxes. In the event of a failure of one of the motors, it was possible to move on one - for this, the planetary gearbox operating mode was provided as a leading one. In conditions of a flat road, it was allowed to turn off one engine to save resource and reduce consumption. Movement on the water was carried out by water cannons, and control was carried out by three rudders, while the possibility of sailing on only one working motor remained. In the transfer cases, which are responsible for the transmission of torque to the final drives and water cannons, the clutches had three modes of operation: "Driving on land", "Entering and leaving the water" and "Driving in water". The first mode rotated only the wheels, the second - both the wheels and the water cannon (for a successful exit to a swampy shore, for example), and finally, the third mode was calculated only for the rotation of the water cannon. On water, the ZIL-135 with a gross weight of 15 tons (of which 5 tons of payload) developed a speed of up to 10 km / h.
What happened next
Since the ZIL-135 was developed under an agreement with the Ministry of Defense, it was necessary for him to look for a niche in the army. Naturally, no one needed such an amphibian in an expensive version of a transport and landing truck. After the 135th vehicle proved its high maneuverability and buoyancy (on the water, the amphibian was on a par with the ZIL-485), it was time to think about its practical application. The length of the cargo platform, in principle, made it possible to install tactical missiles, which were being intensively developed at that time. In addition, the military leadership was looking for a suitable wheeled platform for the 2K6 Luna complex - the tracked base of the PT-76 amphibious tank did not satisfy the shaking and low resource of the undercarriage. And this is where the ZIL-135 floating chassis came in handy.
The installation of a tactical missile fully justified the purpose and capabilities of the chassis. It was a very serious "toy" capable of carrying the ZR-10 nuclear warhead. On May 28, 1959, Vitaly Grachev sent the car to Stalingrad on his own to install the Luna missile system (the corresponding order of the Council of Ministers was issued on April 8). The amphibian at the factory was additionally equipped with rear jacks and front wheel stops. By the way, the ZIL-135 had a competitor in the form of the Yaroslavl heavy three-axle YaAZ-214, but the cross-country ability of this machine could not be compared with the four-axle SKB ZIL. After the installation of the "Luna", the vehicle received the name Br-226-II (or 2P21) and went to the Prudboy test site for testing. On land, everything was fine: although the chassis was overloaded with a nine-ton launcher, it coped well with its transport tasks.
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But when the Br-226-II with a rocket entered the waters of the Don, a disaster almost happened. Firstly, the curb weight of the car now seriously exceeded the calculated 15 tons, and secondly, the center of gravity shifted upward. As a result, the floating missile carrier nearly drowned. Considering that there could be a nuclear warhead on board the amphibian, the swimming experiments were stopped. The second embarrassment awaited the ZIL-135 during the first firing. The fact is that the "Luna" starts from an inclined position, spraying the launcher with hot gases with a pressure of several tons. As a result, the ZIL cabin was deformed, the windshields flew apart and, in general, the appearance of the car after start-up required cosmetic repairs. It would seem that the story of the ZIL-135 missile carrier could end there, but at the end of October 1959, modification "B" was born. In this car, the SKB Grachev group took into account the experience of testing the previous model and lengthened the wheelbase by 400 mm in an attempt to avoid the tendency to gallop. The motors were replaced with serial 110-horsepower ZIL-123F from armored personnel carriers. In total, four prototypes were produced, which did not make much of an impression on the military, and the topic of floating wheeled vehicles was temporarily covered up. And the story with the weak resistance of the base chassis to the hot gases of a tactical missile found an unexpected continuation.
Associate Professor of the Department of MVTU named after Bauman Valery Tsybin proposed to assemble the cabin from fiberglass, which can be reversibly deformed. The idea was accepted and for the first time in the automotive industry, a section for the assembly of fiberglass products was organized at the ZIL SKB. After all the adventures with the ZIL-135 amphibious vehicle, Grachev's office received an assignment from the military to develop a chassis for a 12-meter container installation of S-5 cruise missiles from the Chelomey Design Bureau. In the course of experimental work, exclusively land-based ZIL-135E and ZIL-135K appeared.
As you know, the idea of placing tactical missiles on wheeled amphibians has not been completely abandoned. A decade later, the famous "Tochka" appeared, placed on a three-axle floating BAZ-5921. This car can also be confidently considered a product of the engineering school of Vitaly Grachev.
