In 1955, at the Pavlovsk Automobile Plant named after Zhdanova begins to work in the design and experimental department, headed by the creator of the famous Pobeda Yu. N. Sorochkin, who has left the GAZ plant. It was this department, a year after its appearance, that developed the PAZ-652 bus, which in its design differed from the traditional models of that time.
How it all began
It so happened that in the domestic automotive industry, the truck chassis was the base for the bus chassis. This is what predetermined the further layout of the body of the future bus, virtually eliminating the possibility of further development of the industry. At the same time, all the specialists involved in the development of new models perfectly understood that a truck and a bus are different equipment with different purposes. Therefore, the chassis design of the truck was not quite suitable for the bus. Pavlovtsy decided to move away from the prevailing tradition and create their own small-class bus, with a wagon layout and a design different from others.
Design basis
First of all, in the new model, the designers changed the main thing: if earlier the basis of the bus was a cargo chassis, to which its body was attached from above, now the body itself had to play the role of the supporting system. It was a frame structure with the necessary components and mechanisms mounted in it.
The well-established cargo GAZ-51A served as a donor for the filling of the future PAZ-652.
The body frame, like the frame, was made of steel, the sheet thickness of which was 0.9 mm. A bunch of all the elements and key components of the structure was carried out using spot welding. This allowed to reduce the overall weight of the frame while maintaining the necessary strength and bearing capacity.
Glazing "Groove"
The PAZ-652 bus received glazing, which visually gave the overall lightness of the entire structure. The windshield was quite large, with a curved shape, providing a good overview of the driver, both in direct visibility and through the side rear-view mirrors. What could not be said about the old "groove", a bus of the 651st model.
The designers equipped the windows of the cabin with opening windows, which was an important addition, especially in hot weather. The roof was also not without glazing. Tinted windows mounted in its slopes made the design of the PAZ-652 quite attractive for that time. However, it was these glasses that could spoil the appearance of the bus if they were damaged. The fact is that they were a three-layer structure, the so-called "triplex". The advantage of such a glass was that it did not break upon impact, but was covered with light stripes-cracks that stood out ugly against a dark tinted background.
All the rest of the glazing was carried out by "Stalinites" - glass that had undergone special tempering. Its peculiarity was that it could withstand a blow even with a hammer, but if it still crashed, it crumbled into small cubes without sharp edges, eliminating the possibility of injuring people. Thus, an additional safety factor for the driver and passengers worked in the PAZ-652.
Bus salon
The first thing that the designers did was to delimit the space, as if separating the technical part together with the driver’s seat from the passenger compartment. For this, a sheet of plexiglass was installed on the transverse duct located behind the back of the driver's seat.
The bus also provided for two side seats specially designed for the conductor, as indicated by a plate attached to the wall above the chair.
The interior walls were faced with plastic or fiberboard with a treated front surface. This compares favorably with the old “groove” model, which was lined with cardboard on the inside. Cardboard over time began to warp, crack, crack, and eventually fell away.
The bus was supposed to be used to transport both seated and standing passengers. For the latter, handrails attached to the ceiling were provided along the perimeter of the cabin.
For boarding and alighting people in the bus there were two curtain doors on the starboard side, equipped with a vacuum control drive.
Some more features
In the new “groove” there was one moment that did not fit into the usual framework of the automotive industry at all. Designers installed a cooling radiator not traditionally in front of the engine, but on the side of it. At the same time, it became possible to use a special canvas cover to combine the fan casing with the bus duct system. Thanks to this, during the operation of the bus in winter, warm air discharged from the engine was transported directly to the passenger compartment. At other times, the cover folded and fit into the radiator compartment.
The designers themselves placed the engine in the cabin to the right of the driver, in a special opening engine compartment. The walls of the compartment were laid with a layer of thermal insulation, and the top cover was sheathed with dermatin. Thus, the driver got access to the engine directly from the passenger compartment of the bus.
The brake system was equipped with a vacuum booster, and shock absorbers were added to the springs in the suspension.
As for the lighting, here, in addition to elements from the GAZ-51A, devices from Pobeda were also used. Plus to them, retroreflectors (reflectors) were added behind the bus.
PAZ-652: technical specifications
- Dimensions - 7.15x2.4x2.8 m (length, width and height, respectively).
- PAZ curb weight is 4.34 tons.
- Gross weight - 7.64 tons.
- The capacity of the cabin is 42 seats, of which 23 are sedentary.
- Ground clearance - 25.5 cm.
- The engine is a four-stroke, six-cylinder, with a carburetor fuel system.
- Power unit power - 90 l / s.
- Engine displacement - 3, 48 cubic meters. cm.
- Clutch - single disc design, dry.
- The maximum possible speed is 80 km / h.
- Gasoline consumption - 21 liters per 100 kilometers.
Start of production and first modifications
The first tests of an experimental bus began in 1956, in the same year an order was signed to begin preparations for the mass production of new cars. After 4 years, in 1960, the first serial "groove" came off the assembly line of the plant.
The bus, in addition to the main version, had two more modifications: 652B and 652T.
The modified “groove” 652B differed from the reference model in a slightly modified body structure and the design of the front of the machine.
Another modification, PAZ-652 T (tourist), was produced with additional amenities in the cabin and one door for boarding passengers.
For all 10 years of serial production, 62,121 buses rolled off the assembly line of the plant. Throughout the entire production period, the PAZ was refined: changes, various amendments were made to its design, and the shortcomings identified during the operation of the machines were eliminated. But in general, the bus coped with its functions perfectly, which is why it lasted so much time in the series.