To begin, probably, it is necessary with definitions. And already they will set the further development of the theme of our narrative.
So, today no one needs to explain what self-propelled artillery mounts (self-propelled guns) or self-propelled guns are. And self-moving?
"Self-propelled" - they go themselves. "Self-propelled" - they themselves move. The whole difference between the words “walk” and “move”. To walk is to travel long distances. Self-propelled guns and walked next to tankswhere it was ordered. Moving guns are those that could move independently.
Moving guns in a combat situation is quite a complicated procedure, which also takes a lot of time. And requires a force, no matter what it is, a horse or a tractor.
The most vivid example: the sudden attack of enemy tanks on the positions of the battalion where it was not expected at all. The use of anti-tank artillery is instantly simply impossible, since the guns are not only enough to be assembled, you still need to adjust the force, hook and move. And the enemy is not waiting ...
In fact, the first step in this direction was already taken in 1923, at the Leningrad plant "Krasny Arsenalets".
Designers N. Karateev and B. Andrykhevich developed a self-propelled chassis for the 45-millimeter cannon. Inside the lightly-armored hull of the structure called “Arsenalets”, there was an opposed gasoline engine from a motorcycle with a capacity of just 12 hp.
The motor accelerated the chassis weighing a little less than a ton to 5-8 km / h. It is unlikely that the Arsenalets could keep pace with the troops on the march with such driving characteristics; therefore, the tracked course was supposed to be used only for moving directly on the battlefield.
For the calculation of the gun seats were not planned. The driver simply walked behind the Arsenalz and drove it with two levers.
A prototype self-propelled gun was submitted to the tests in the 1928 year. Of course, the military was interested in a self-propelled chassis for field artillery, but the Arsenalets' design did not provide any protection to the calculation and did not have acceptable speed and maneuverability. With patency everything was in order. However, after testing the project was closed.
Self-propelled gun "Arsenalets", which is undoubtedly one of the first projects in the world, rightly belongs to the class of self-propelled artillery installations. Precisely because at the time of its development any serious projects of ACS simply did not exist.
At the same time, the later self-propelled guns of domestic and foreign production were armored chassis with guns and means of protecting the fighters installed on them.
The idea of "Arsenalts" was not forgotten. And the idea of self-propelled guns began to be developed at the Design Bureau of F. F. Petrov even during World War II.
In 1946, the anti-tank gun D-44 caliber 85 mm was adopted by the Soviet Army. This weapon was very successful, so much so that the D-44 is still in service in a number of countries around the world.
In 1948, the engineers KV Belyaevsky and S. F. Komissarik (photo, alas, could not find) proposed the idea of a tool that could move around the battlefield without the help of a tractor. The developers completed the project of a self-propelled gun, which was approved, and in 1949, Plant No. XXUMX began to manufacture a prototype.
The next few years were spent on testing, identifying and correcting deficiencies. In November, the 1954 of the self-propelled gun was put into service under the designation SD-44, that is, the “self-propelled D-44”.
When developing a self-propelled gun, the OKB-9 designers took the path of least resistance. The barrel group of the original D-44 gun did not change at all. Barrel-piece with a two-chamber muzzle brake and breech remained the same.
A solid refinement has undergone only gun carriage guns. A special metal box was attached to its left frame, inside of which was placed the M-72 motorcycle engine with 14 horsepower. Engine power was transmitted to the drive wheels through the clutch, gearbox, main shaft, rear axle, cardan drive and final drives.
The gearbox provided six forward gears and two reverse gears. On the bed also fixed seat driver. At his disposal there is a steering mechanism that controls the additional, third, wheel of the gun, mounted on the end of one of the beds. During the transfer of the cannon into a fighting position, the steering wheel was folded sideways up and did not prevent the collar of the bed from resting on the ground.
There is also a headlamp to illuminate the road in the dark.
Hollow base plates were used as fuel tanks.
In the stowed position, the SD-44 gun weighed about 2,5 tons. At the same time, it could drive at speeds up to 25 km / h, and 58 liters of gasoline were enough to cover 22 kilometers.
The main method of moving the gun was still towing with other vehicles with more serious driving characteristics.
It is noteworthy that a winch for self-pulling was part of the equipment of the CD-44. In the stowed position, its cable was stored on the bulletproof shield, and if necessary it was fixed on a special drum on the axis of the driving wheels.
The winch was driven from the main engine M-72. It took no more than a minute to transfer a gun from a combat position to a marching position and vice versa. With the advent of the military transport aircraft An-8 and An-12, it became possible to transport the SD-44 cannon by air and also to parachute it with a parachute.
And quite naturally, the main paratrooper of the USSR, Vasily Margelov, laid eyes on the cannon, who realized that an instrument capable of being moved with an airplane or a helicopter and somehow leaving the landing zone was worth it.
Tactical and technical data SD-44
Caliber, mm: 85
Barrel Length, Caliber: 55,1
Weight in combat position, kg: 2250
Angle GN, degrees: 54
Angle VN, degrees: -7; + 35
Projectile initial velocity, m / s: 793
Max. firing range, m: 15820
Max. self-speed, km / h: 25
Projectile weight, kg: 9,54
Maximum range of OFS, m: 15820
Rate of fire, rds / min: up to 15
Calculation persons: 6
In the mode of movement, the gun moves the barrel back, while on it you can place the calculation and part of the (small) ammunition.
CD-44 is able to overcome rises to 27 °, fords to a depth of 0,5 m and snow drifts with a height of 0,30 ... 0,65 m. Power reserve on a paved road - to 220 km.
A total of 704 cannon SD-44, both new and converted from the D-44, were released.
In addition to the USSR army, SD-44 was in service with the armies of Albania, Bulgaria, the GDR, Cuba and China.
Here's a story. Once again, Soviet engineers have shown that they can replay the whole world.