The tank-building program of the Soviet Union provided for the appearance in the army of several types of armored vehicles at once - from light T-37A to giants T-35. But the T-26 and a series of high-speed BTs were to become truly massive. If in the first case, a 90-horsepower gasoline engine from the Leningrad plant named after V. I. Voroshilov, but the BT required a different technique. As everyone remembers, the 400-horsepower Liberty aircraft engine became a temporary measure, but its cost and a chronic shortage of components seriously hampered the development of tank building. Innokenty Khalepsky, head of the Red Army Motorization and Mechanization Directorate, in this regard, back in 1929, warned that "the power of the motors and the speed of the tractors in no way meet the tactical requirements of motorized units." This problem was superimposed on the demand of the USSR leadership at any cost to increase the production of tanks with a chronic shortage of engines. At first, the problem was solved by installing an M-17 aircraft engine on high-speed tanks, but Rybinsk Aviation Engine Plant No. 26 could, in particular, in 1934, allocate only 80 engines to BT. The remaining 220 were intended for the T-28 medium vehicle, and later the heavy T-35 was supposed to approach this story.
Why did the industry decide to switch to heavy motor fuel? In accordance with the decree of the Central Committee of the All-Union Communist Party of Bolsheviks dated November 15, 1930 "On the situation in the oil industry", the rational use of petroleum products and the massive transition of all types of transport to diesel fuel were at the forefront. In many ways, this was a forced measure - the young Soviet republic lacked the capacity for deep processing of natural hydrocarbons into high-quality gasoline. In turn, the engineers were impressed by the high fuel efficiency, fire safety and reduced interference to radio communications due to the absence of electric spark ignition in diesel engines. According to Evgeny Zubov in the book "Tank Engines (From the History of Tank Building)", the first attempt to develop a heavy fuel engine for ground vehicles was the AMBS 2-stroke diesel engine. The abbreviation was the abbreviation of names (Alexander Mikulin and Boris Stechkin, they were the ones who built the engine for the Tsar Tank in 1917). However, such an ambitious task was left without continuation.
After not the most successful attempts to create oil engines of the Alpha and ON-1 series in the second half of the 1920s, Russian engineers designed a high-speed aircraft diesel engine AN-1 (“aviation oil”) at the Central Institute of Aviation Motors. It was a 12-cylinder unit, in layout no different from the traditional gasoline counterparts. Diesel in the original version developed 750 liters. with., but over time it was possible to disperse it to 1250 liters. with. - it was in this modification that he went into the series. The aviation oil engine gave a whole series of engines of various powers, which were installed on airplanes, locomotives and river ships.
An attempt to create a truly tank diesel engine was made at the Voroshilov plant in 1935, when the DT-26 engine was developed for the T-26 light tank. The motor had a mass of 500 kg, a working volume of 7, 16 liters and developed 91 liters. with., however, the tests failed, the developments on it were postponed. Two years later, at the Kirov Experimental Mechanical Engineering Plant, they began to build two diesel engines at once for the T-26 - the first was a 4-stroke D-16-4, and the second was a 2-stroke D-16-2. Both units developed 130 liters. with. and had eight cylinders (D-16-4 was V-shaped, and D-16-2 was opposed). Actually, then the understanding came that the V-shaped layout of the diesel engine with a 4-stroke cycle would be the most optimal for the tank. The D-16-4, due to its excessive dimensions (did not fit into the MTO T-26), never went into production, which finally left the Soviet light tank without a heavy fuel engine. A little later, in 1936, a new project for the construction of a diesel engine for medium and heavy DMT-8 tanks was launched at the Kirov plant. The innovation for 2-stroke engines at the time was modular design - each segment had two cylinders, a common combustion chamber, intake and exhaust valves. An 8-cylinder diesel engine was assembled from four modules or compartments, and a 10-cylinder from five, respectively. The first in the business of modular design in 1930 was the designer A. A. Mikulin, when he was developing the M-34 aircraft engine. He then made an in-line engine from the projected V-shaped engine and on it he had already worked out the entire experimental part. Fast, simple and inexpensive … And in 1939 the DMT-8 engine went for testing, but it showed unsatisfactory results - vibrations during operation, high oil and fuel consumption, as well as piston burnout. He never reached the DMT-8 series - the situation was saved by the development in Kharkov of a 12-cylinder engine, which would later become the legendary V-2.
Kharkiv legend
We need a "powerful diesel engine tractor" - this is exactly the task that the Kharkov steam locomotive plant received in the spring of 1931 from the department in charge of the production of steam locomotives, carriages and diesel engines. The name of the department was very funny - "Parvagdiz". So, this very "Parvagdiz" set a difficult task for the Kharkovites to develop a diesel tank engine virtually from scratch. In order to meet the tank designation, a diesel engine must be adapted to frequent changes in tractive effort and speed, as well as not be afraid of shaking, impacts and high levels of dustiness in the air. As mentioned above, in addition to the Kharkov plant, similar tank engines were also engaged at the Leningrad State Plant No. 174 named after K. E. Voroshilov, however, the level of competence in this area was higher among the Kharkovites.
At the steam locomotive plant, back in 1912, a division was created that deals with the program of internal combustion engines, where the first oil engines appeared a couple of years later. Moreover, the line was wide: from small 15-horsepower to ship giants of 1000 hp. with. Already in the post-revolutionary period in Kharkov (in the factory department "400" or, as it was also called, thermal) they created a four-cylinder diesel D-40, developing 470 hp. with. and featuring a very low 215 rpm. It should be noted that, to the credit of the developers, the diesel was equipped with injectors and a fuel pump of its own design. In addition, due to its dimensions, the engine was rather stationary and was not suitable for the MTO of the tank. We needed a resourceful and compact engine with great modernization potential, so that it could be installed in light, medium and heavy tanks. And it would also be nice to be in the nacelle of some bomber. The task was formulated to develop a 12-cylinder V-shaped 4-stroke revolving diesel engine with a capacity of at least 400 hp. They called it BD-2 and it was intended for a wheeled-tracked light BT - it was necessary at all costs to replace their gasoline aircraft engines M-5 and M-6. It is necessary to dwell here separately and explain that there was no such technique in the world until that time. The requirements were unique. The engine must be powerful, while compact and suitable in terms of characteristics for tough tank operation. And it is very desirable to bypass the German low-power (only 110 hp) diesel "Saurer" in terms of specific parameters, which at that time was already limitedly installed on the English "Vickers".
To work out the necessary experimental data in Kharkov, at the beginning of 1932, a 2-cylinder BD-14 with a capacity of 70 liters was built. with. As discussed above, this modular design approach saved time and resources. In the compartment, engineers worked out the engine's operating cycle, the crank mechanism and the features of the gas distribution. Calculations showed that in a 12-cylinder version, a diesel engine could develop 420 hp at once. with., which exceeded the basic requirements and was much better than the German "Saurer" - in a similar configuration, it would have accelerated to 330 liters. with. After testing the compartment in April 1933, a full-fledged BD-2 diesel engine was assembled and placed on a test bench. With a relatively small weight of 640 kg and a working volume of 38, 17 liters, the prototype of a tank engine at 1700 rpm produced 400 liters. with., but turned out to be "raw" for most of the nodes. In fact, the BD-2 could operate without breakdowns for no more than 12 hours. Nevertheless, after a superficial repair, the prototype was installed on the BT-5, which, as a result of a heart transplant, was never able to return to the factory shop on its own - the motor invariably failed. Until October 1934 alone, about 1150 design changes of one level of complexity or another were made to the BD-2. In the future, it was this prototype that received the in-plant name "Order B", from which the B-2 will appear.
In the book "Confrontation" Daniyal Ibragimov cites the memoirs of the designer Nikolai Alekseevich Kucherenko, who very accurately described the events of that time:
“Realizing that military affairs cannot stand still, our factory team set itself the task of replacing the gasoline engine with a powerful small-sized high-speed diesel engine. But in the practice of tank building there was no such diesel engine yet. And then the decision came - to create it … And the engine was created! However, he did not immediately fall into place. Like an obstinate horse, the new engine was a lot of trouble. During the tests of the modernized machine, various breakdowns occurred every now and then. But the designers did not despair. Diesel gradually began to get used to it - to work steadily on a test bench and in a prototype."
