MAZ 7907: technical characteristics, fuel consumption, photo

The history of technology, especially the military Soviet period, has many glorious pages. A considerable contribution to the writing was made by the designers of the Minsk Automobile Plant, who worked in the department of wheeled tractors, which eventually became a separate MZKT plant. The MAZ 7907 tractor was a remarkable and for today unique creation.

Historical background of creation

In response to the creation by the American specialists of the intercontinental MX rocket, the launch mass of which was almost 90 tons, the leadership of the USSR Defense Ministry decided to develop an analog. Such a response was the rocket RT-23 "Good", according to the NATO SS-24 Scalpel weight of almost one hundred tons. The transport-launch container with a rocket inside weighed already one hundred and five tons. Its length was almost twenty-three, and its diameter was two and a half meters. The design dimensions of the launcher were: length - 32 m, height - more than 5.5 m.

But to create a rocket is not enough, a cargo with such a mass and such dimensions should still be transported along the roads, and sometimes without them.

Since the special subdivision of MAZ already had a rich experience in designing heavy-duty tractors, it was this plant that received the order to manufacture a wheeled vehicle with a carrying capacity of more than 100 tonnes.

The result of two-year work of the company's specialists, the chief designer of which was doctor of technical sciences BL Shaposhnik, Hero of Socialist Labor, laureate of the Lenin and State Prizes of the USSR, and became a unique MAZ 7907.

Specifications

This project was called "Celina-2". The first was a MAZ 7906 eight-axle tractor with a carrying capacity of 150 tons.

Tractor MAZ 7907 (24x24) was developed for two years. And in 1985, two samples were collected for sea trials. The equipped weight of the conveyor was 66 tons with a carrying capacity of 150 tons. The estimated maximum speed on the highway (hard and smooth coating) is 40 kilometers per hour. In tests with the layout of the launcher, the conveyor showed a speed of 25 km / h.

Impressive dimensions of the tractor. Its length was more than 28 meters, width - 4.7 meters, and height - almost 4.5 meters. The width of the wheel track, both the front and rear, was more than 3.3 m, and the ground clearance was 465 mm. The turning radius of the chassis is 27 meters. The base of the front and rear bogies is not the same - 9,065 and 9,22 m. The distance between the axles of the wheels is 1,75; 1.8 or 1.855 m.

Twelve pairs of driving wheels VI-207 of domestic production had dimensions of 1660 x 600-635 mm. That is, the diameter of the wheel was in the growth of the average person. How small are the people next to this monster MAZ 7907, photos from the report on the transportation of boats show very clearly.

Design Features

To provide such impressive carrying capacity, all MAZ 7907 wheel sets had to work with full load without hanging wheels on dirt roads. Therefore, in addition to the suspension design, a power hinge on bearings with one degree of freedom was provided in a spine frame that retained rigidity in the horizontal plane. That is, the platform was two-tiered on two six-axis trolleys that could move vertically relative to each other by an angle of up to 8 °.

To ensure the maneuverability of such a long base, eight of the twelve pairs of wheels turned. These were the first and last four pairs. And provided for two options for the rotation. In the first eight wheels were turned in one direction, and eight - in the opposite direction. In the second, the turn was synchronous - the so-called movement "crab" or sideways.

Power plant MAZ 7907

MAZ of such capacity and power required an engine with special characteristics. The three-shaft gas turbine GTD 1000T FM engine with a capacity of 1250 liters was installed on the tractor. from. Kaluga Motor Plant, which is now called GUP "Zavod im. V.Ya. Klimov. " The engine was mounted on the front console of the frame under a three-seater cabin with three windshields.

Many people call the tank engine, although at the plant, modifications of the base engine for missile carriers, including MAZ 7907, were specially created. The fuel consumption in the open-access literature is indicated only for tank engines, and for the GTD-1000TF with a capacity of 1100 liters. from. It is 235 g / hp * h, and for GTD-1250 at 1250 liters. from. - 225 g / hp * h. Given that a hundred kilometers of track at maximum speed the tractor could pass for four hours, then it was necessary to spend on it about one and a half tons of fuel.

The generator of alternating current VSG-625, installed in the block with the engine, fed the units of electromechanical transmission TE-660-24 and synchronous electric motors of air-oil cooling installed inside the frame, separately for each wheel.

Oil radiators and electric control units were placed under parallel covers at the rear of the chassis.

Advantages and disadvantages

Compared with the previous conveyor MAZ 7906-twelve-axle tractor had significant advantages. The best were controllability, soundproofing of the cabin, higher manufacturability and survivability, as the mobility of the installation was maintained even if the drive of eight wheels was damaged.

But the disadvantages of the tractor MAZ 7907 enough. Electromechanical transmission differed in low efficiency and low efficiency. In addition, the heavy machine had low permeability on soft soils and insufficient dynamics of acceleration, increased axial load.

The design required serious improvements, although prototype rocket test vehicles were successfully tested. Perhaps the shortcomings would have been eliminated over time, but the cold war had ended and the stage of disarmament had begun, the strategic missile forces had become unnecessary.

MAZ 7907 in action

Unique conveyors remained at the factory range, but one of the tractors passed a kind of test drive, which, however, confirming the declared characteristics, ended for him deplorable.

After ten years of oblivion, in the summer of 1996, it took by land to deliver to the destination a pleasure craft 40 meters long and weighing 90 tons. Moreover, the owners loaded building materials into the bow section so that they would not spend money on their delivery. It was discovered after loading that the alignment of the vessel was broken, and it was necessary to urgently load the stern. As a result, the total weight of the vessel was about one hundred tons.

For almost two months the specialists of MZKT prepared the equipment for work. The subframe that existed for fixing the TPK was redesigned. Now these were lodgements for the bottom of the pleasure craft. We started the gas turbine, checked the electric motors of the wheels. Four engines did not work. One hundred and seventy tons of total weight made a way on twenty wheels. As it was stated when creating a tractor with serial number 7907.

MAZ traveled more than 200 km at a speed of about 20 km / h. Only when crossing the bridge over the Berezina River, not designed for transport of such a mass, part of the cargo took on a four-axle MZKT-79091 with a winch and a stern mast, lifting the stern of the boat above the platform.

When unloading, truck cranes and tractor trucks were driven back into Naroch lake. The electric transmission of the test with water could not stand it. Back to the MAZ 7907 base, he did not reach the base any more, brought his factory tractor.

Inverted history page

In another ten years two of the two rocket trucks were assembled at the factory landfill. It turned out to be a monumental monument in the museum exposition on the territory of the Minsk Wheel Tractor Plant. Unfortunately, there were no tasks for today, for the solution of which such a powerful technique as MAZ 7907 would be needed.

Photos of a unique car are not so common. The sad moments of decline and destruction and black-and-white photographs now almost two decades ago, on which the path from the Berezina River to Lake Naroch is imprinted - that's all. But they are enough to show the power of the tractor and the power of thought of the Minsk designers, headed by BL Shaposhnik, for whom this project was the last.