Dinosaurs of the Country of the Soviets: Great traction
The peeling and rusty grand Soviet cars standing in the open air have a rather sad look. It is hard to imagine that just a couple of decades ago, these “rocket-savers” with their monumentality, the roar of engines and impressive cross-country ability made an indelible impression on those around them. Looking at them, Soviet citizens were assured that nothing threatens one sixth of the land that these machines defend.
Two? Four? 24 driving wheels!
The 8x8 wheel arrangement (eight wheels, and all driving) is respected by people who know. Meanwhile, until today, the MZKT mass-produced tractors with wheel formulas 10x10, 12x12 and 16x16. Moreover, on the territory of the plant you can meet the amazing car MAZ-7907. This tractor stands on 24 wheels, and they are all leading. A gas turbine GTD-1250 with a capacity of 1250 hp was installed under the contours of the cabin. It spins an impressive size generator that supplies energy to all 24 electric wheel drives.
Since the car was never accepted for service, it can be stated that this is the only 12-axle all-wheel drive tractor in the world.
Leaders from Minsk
Surprisingly, the history of multi-axle MZKT cars began with a tractor that had only two wheels - it was intended to create special self-propelled vehicles. The first work of the Special Design Bureau (SKB-1) created at MAZ in 1954 - the MAZ-529 uniaxial tractor - was used in conjunction with a scraper. With a curb weight of 9 tons, he could tow a 25-ton trailer. Boris Lvovich Shaposhnik became the chief designer of the new unit, formed for the development of multi-axle all-wheel drive heavyweights. Before the war, he worked as the chief designer of the capital ZIL, and then headed UlZIS (later UAZ).
An experienced designer quickly created a team of talented specialists. Thanks to them, new cars could boast a whole range of technical innovations. The tractors proved themselves so well that soon three new plants appeared in the USSR: BelAZ, MoAZ and KZKT (Kurgan Wheel Tractor Plant). They began with the release of developments of the Shaposhnik division.
The first major achievement of SKB-1 (later MZKT) was the four-axle MAZ-535 with all driving wheels, which was born in 1957 and was designed to tow 10-ton artillery systems. It was the first tractor in the USSR with hydromechanical transmission. True, the gear shift was still semi-automatic: the driver (and not the control unit) chose which gear to engage.
For better cross-country ability and better maneuvering, the designers used an independent torsion bar suspension. The car also had a centralized inflation of tires, a record number of differentials (there were seven!), Original designs of the frame, steering gear and brake system.
From the design of tractors for artillery systems at the MZKT, they soon moved on to the development of a truck tractor with a semi-trailer designed for transporting tracked military equipment. And later, automotive designers began to work closely with the creators of rockets. The first such development was the four-axle MAZ-543, designed for the launcher of the first Soviet solid-fuel tactical operational missile Temp. On the basis of this car, a whole family of Soviet missile carriers was developed.
The era of heavy rockets
The noteworthiness of the rocket carriers was that they had two separate double cabins. In one sat a driver-mechanic and crew member, in the other - a crew commander and crew member. The rocket (or its simulator) was between the cabins, which allowed to reduce the height of the car. For the first time in domestic practice, the cabins were made of fiberglass: this made them easier, and besides, such a two-layer cab was able to withstand the shock wave from a nuclear explosion. For this case, special photochromic glasses were also provided: during the explosion, they became opaque, preventing the crew from being blinded in the cockpit.
The weight, the range of missiles, the number and power of warheads grew - the military each year needed more and more powerful tractors. The growing payload required an increase in the number of axles, and production of the six-axle MAZ-547 soon began. For the Topol complex that appeared later, twelve wheels was already not enough - the MAZ-7912 semi-axle chassis with a 14x12 wheel arrangement was designed for it. Increasing the range of the rocket and increasing its weight required the creation of an eight-axis chassis MZKT-7923. When designing this machine, the designers abandoned the traditional drive with a huge number of driveshafts, using a hydraulic drive instead. But the gear range of the hydrostatic transmission was insufficient - at low revs and with high torque, the pressure in the transmission hydraulic system became very high, and due to leaks in hydraulic motors and transmission efficiency pumps, it fell. And at high speeds, the transmission efficiency fell already due to increased friction in hydraulic motors and pumps. So they also refused hydraulics, using an electric drive instead. Its creation was entrusted to Novosibirsk specialists from the Research Institute of Complete Equipment, who successfully completed the task. A powerful gas turbine engine was borrowed from the T-80 tank, upgrading it to work with a generator. To prevent electric motors from overheating, they used oil cooling. The Cold War was in full swing, and “to maintain equilibrium with the United States, ” urgently needed to create new cars. So, perhaps the most interesting cars developed by the MZKT were born. Probably the most expensive in the world! The Soviet government spared no money, and the most expensive materials were used. In particular, titanium parts were widely used to reduce the weight of the machine!
One of the most impressive experimental tractors in the USSR was the six-axle MAZ-7904. The total mass of this car was 360 tons, and the carrying capacity was 220 tons, remarkable performance for an all-wheel drive car. Since the USSR did not produce tires that could withstand the enormous loads that were falling on each axis of this car, "tires" were ordered in Japan - the tractor rode on giant Bridgestone tires with a diameter of 3.1 m. It is curious that the car was not equipped with one, but immediately two motors. The first, marine (1, 500 hp), set the wheels in motion through two hydromechanical gears, while the second, a regular 330-horsepower diesel engine, was used to drive auxiliary equipment.
For the Tselina project, in 1984 a pair of eight-axle MAZ-7906 cars with all driving wheels were manufactured, and a year later, a pair of twelve-axle MAZ-7907. The latter machines already used domestic tires with a diameter of 2 and 1.66 m. They were designed for much lower loads compared to the tires on the MAZ-7904, but these tractors had a lower carrying capacity (150 tons) and a larger number of wheels. None of the giant experimental MZKT machines were ever adopted, although almost all of them were successfully tested. With the end of the Cold War, the need for formidable weapons of these machines disappeared.
Military on civilian
With the collapse of the USSR, the need for other military developments of the MZKT also disappeared, and in order to overcome the crisis, many of the machines were recycled for civilian purposes. Rocket carriers replaced multi-wheeled vehicles for drilling, and carriers of artillery systems and tanks were replaced by construction equipment. However, military vehicles did not lose their positions. Orders from Russia resumed, foreign customers appeared - Turkey, the UAE, Egypt, Pakistan, Syria, China. In China, even organized their own production of machines design MZKT. And when we were at the factory, we found officials from the UAE there who were accepting a batch of tank carriers for their army. Arabs wandered around the plant, looking with interest at the huge tractors of the Soviet era. Leaving the factory, I also looked at the giant MAZ-7907 for the last time. Most likely, this poor fellow will never budge himself. At the time of Yeltsin, factory workers were asked to help the state: they had to transport an 88-ton ship from the Berezina River for 250 km to Lake Naroch. The car, which had stood idle for over ten years without movement and maintenance, was quickly reanimated, a gas turbine was launched, and the wheel drives were checked for serviceability. Not all of them worked, and the tractor hit the road with the top 20. The task was completed, although several more motors failed in the process.
Finally, we asked what fate awaits the unique machines, and received an encouraging answer: they are preparing to become exhibits of the permanent exhibition of the MZKT. So lovers of big cars in Minsk will have something to see.The article was published in the journal Popular Mechanics (No. 10, October 2007).