As you know, when creating the very first Soviet BMP-1 infantry fighting vehicle, several vehicles were developed at once, differing from each other in layout, power plant and even undercarriage. As a result, a tracked vehicle became a new type of equipment in the Soviet army. However, wheeled and even combined wheeled and tracked armored vehicles competed with it. All the developments submitted to the competition in the course of comparative tests have shown their advantages and disadvantages. As a result of their comparison, the military chose the tracked vehicle "Object 765" / BMP-1, developed in the Chelyabinsk GSKB-2.
Experienced BMP "object 765"
A full-fledged alternative to the tracked "Object 765" can be considered the project of the wheeled armored vehicle "Object 1200", created in the design bureau of the Bryansk Automobile Plant. Based on the results of the first years of operation of the BTR-60 wheeled armored personnel carrier, Bryansk engineers decided to develop a wheeled armored vehicle. In addition, they already had some experience in creating such a technique. The wheel chassis with the 8x8 formula was considered capable of providing all the necessary technical and combat qualities. In addition, the wheel propeller promised the possibility of unification with existing technology. The development of the "Object 1200" began in 1964 under the leadership of F. A. Rozova.
Despite the possibility of unifying a large number of parts and assemblies of the undercarriage, when creating the new "Object 1200", the developments on the BTR-60 project were almost not taken into account. That is why the welded armored hull of a promising infantry fighting vehicle has characteristic recognizable contours. It was proposed to weld the body of the machine from rolled sheets with a maximum thickness (frontal part) of 60 millimeters. Thus, the armor provided protection for the crew and units from bullets and shell fragments. At the same time, the frontal projection could withstand the fire of large-caliber machine guns. Only bulletproof booking was due to the then views on the appearance of modern warfare and the requirements for advanced technology.
The internal layout of the Bryansk BMP is quite interesting. In the future, something similar was used on some foreign machines. In the front of the hull, under the cover of thick frontal armor, the workplaces of the driver and commander were placed. Immediately behind them were three landing sites for the landing. A fighting compartment with a turret was placed in the middle of the hull, behind which were the engine-transmission and main troop compartment. The engine and auxiliary units were located on the left side of the rear of the vehicle. The remaining volume of the stern was taken under the seats for four fighters with weapons. Embarkation and disembarkation was to be carried out through one aft door and two hatches in the roof. The front volume of the troop compartment was connected to the rear by means of a narrow passage.
The basis of the power plant of a promising infantry fighting vehicle was to be a diesel engine UTD-20 with a capacity of 300 horsepower. The transmission transmitted torque to all eight drive wheels. The latter were equipped with a hydropneumatic suspension and a pumping system. An interesting feature of the undercarriage of the "1200 Object" was the fact that the driver could change the ground clearance of the car depending on the conditions by adjusting the pressure in the shock absorbers. Two water cannons, borrowed from the PT-76 amphibious tank, were placed in the rear of the vehicle specially for movement on water. Their intake windows were on the sides, outlet pipes were in the aft hull sheet.
With a total combat weight of the new BMP of about 14 tons, the 300-horsepower engine provided it with a specific power of about 21-21.5 horsepower per ton. Thanks to this, the "Object 1200" could accelerate on the highway to a speed of 90 kilometers per hour and cross water obstacles at a speed of about 10 km / h. There was enough fuel for a 500-kilometer march along the highway.
The combat module was the same for all infantry fighting vehicles that participated in that competition. It was a one-man turret with a 73-mm smooth-bore gun 2A28 "Thunder" with 40 rounds of ammunition. A PKT machine gun of 7.62 mm caliber was paired with the cannon (transportable ammunition - 2000 rounds). In addition, the turret had a launch rail for guided missiles of the 9K11 Malyutka anti-tank complex. Inside the fighting compartment, up to four such missiles were placed in packs. After launch, preparation for a new one was carried out manually, from the tower.
In 1965, Bryansk car builders assembled the first and, as it turned out later, the last prototype of the Object 1200 infantry fighting vehicle. Since the towers of all combat vehicles presented for the competition, including the "1200 Object", were almost the same, their firepower was not compared. This fact made it possible to save time and effort on the installation of weapons. Therefore, the "Object 1200" received a simplified turret, in which instead of a gun, machine gun, ammunition and weapon control systems, their weight simulators were installed. It was in this form that the Bryansk infantry fighting vehicle overcame the routes and transported test soldiers.
The characteristics of the "Object 1200", in general, were found to be acceptable, but not without criticism. The soldiers who participated in the tests as "payload" complained about the crowdedness of the troop compartment. Firstly, it was not very convenient for the paratroopers, who were sitting behind the commander and driver's seats, to leave the car through the aft door. It was not easier for those sitting in the stern of the BMP: due to the specific placement of the engine and water cannons on the sides, the passage and the door were not wide and comfortable enough. Other competing vehicles, at least, were not inferior in convenience to the Bryansk "Object 120", or even surpassed it.
And yet, the main problem of the promising BMP was the wheeled chassis. It was better than tracked when driving on prepared roads, but on rough terrain or on water, the balance of power changed. The wheels simply could not provide the vehicle with cross-country ability at the level of tracked competitors. In addition, the wheel chassis was found to be too sensitive to conditions. So, during test swims in sea water, some parts of the brakes got wet enough and became unusable. Another problem associated with movement on water was the adhesion of wet wheels to the shore surface. Coming out of the water, "Object 1200" could only enter the coast with a relatively small slope.
According to the results of comparative tests of all armored vehicles submitted to the competition, the most interesting and promising was the tracked "Object 765", later called the BMP-1. Although it lost at maximum speed (about 60-62 km / h on the highway and up to 7 km / h on the water), the aggregate driving performance on land and on water was much better. For example, caterpillars with special grids made it possible to literally accelerate to a rather steep coastal slope, and on rough terrain did not allow the car to get stuck.
Comparative tests of several variants of a promising infantry fighting vehicle clearly showed all the advantages of tracked vehicles. "Object 1200" and remained in a single copy, which did not even receive weapons. It has survived to the present day and is now kept in the tank museum of Kubinka near Moscow. The theme of wheeled infantry fighting vehicles did not receive any development, and such a chassis for many years remained a characteristic feature of domestic armored personnel carriers.
