Successful combat tests of the super-heavy T-100 tank in the Finnish War of 39, allowed the designers of plant No. 185 to think about the serial production of their brainchild. Moreover, according to the decision of the military council of the North-Western Front, at the end of 1939, the plant received an application for the creation of an engineering assault tank based on the super-heavy T-100.
The Finnish war showed a shortage of heavy armored equipment that must fulfill its specific tasks - transporting assault bridges, delivering explosives or sapper specialists to the enemy's pillboxes, evacuating tanks and artillery under heavy enemy fire.
In the course of the development of an engineering assault armored tank, the designer is given the command to install a 152-mm cannon on it, or something optimal for this project. The project receives the working title T-100-X. The result was a product with a wedge-shaped wheelhouse and a 130 mm B-13 gun, which was installed on the ships of the Red Army. The design of the engineering assault tank gradually evolved into the creation of a self-propelled unit. Modifications to the T-100-X project led the designers to define the tasks of the new product. The project is named SU-100Y - a super-heavy self-propelled gun with an artillery gun.
The designers of the plant could not create two projects, and after requests from the plant management with a request to leave one project, work continued only on the super-heavy self-propelled gun SU-100-Y.
According to some reports, this project has a different name - T-100-Y.
The differences between the SPG and the T-100 tank were minimal. At first glance, the main difference is the turret part with one B-13 cannon instead of two turret guns of 45 and 76.2 mm caliber. In the bottom, the designers made an emergency hatch. The engine and transmission compartments were equipped with special hatches for convenient field maintenance. The upper part of the hull had 20 mm armor.
The rest of the armor retained its basic configuration from the T-100 and was 60 mm thick.
In addition to the turret compartment, the rest of the SPG layout repeated the assembly units from the T-100 tank. In the front part, the armored vehicle control compartment was left unchanged.
An aircraft engine with twelve cylinders and liquid cooling was installed in the stern of the hull. The GAM-34-BT engine was a carburetor version with a capacity of 890 hp. The self-propelled transmission has a mechanical design.
The engine was started by an electric starter "ST-70" with 15 hp. The launch could also take place from compressed air. An axial fan was responsible for cooling the engine compartment, which was installed horizontally on the gearbox.
In the compartment, air entered from the side openings, covered with fine nets, located in front of the engine compartment. After cooling the compartment, hot air coming out of the engine compartment hit the top of the track.
The fuel for the self-propelled unit was aviation gasoline, placed in 4 aluminum tanks, the total capacity of which is 1.3 thousand liters.
The full tanks of the SU-100 Y super-heavy self-propelled gun were enough to cover 210 kilometers on a good road.
Transmission - a five-speed gearbox of the main 3-disc clutch and multi-plate side clutches with band and single-row gear brakes in a simple and ferrodo design.
Cannon B-13, model 29. Installed on a pedestal. Ammunition - 30 rounds of separate loading feed. The ammunition included armor-piercing and high-explosive shells and grenades.
Torsion bar suspension SU-100Y:
- 16 skating rinks 2-pitched support version;
- 10 additional rollers with amortization;
- two rear driving wheels;
- two front guide wheels with track tensioning mechanisms;
- two small-link caterpillars;
The tower is made in the form of a cabin according to a simplified scheme. The wheelhouse allowed the gun to have small vertical and horizontal guidance angles (-2 to +15 and -6 to +6, respectively). The mechanisms for aiming the gun are made according to the sector type. Aiming was carried out on the Hertz panorama. The shell of this weapon weighing 36 kilograms did not lose armor-piercing of 40 mm at a distance of more than 4 kilometers.
For a separate loading feed, the gun had a good rate of fire at that time of 4 rpm. This rate of fire was achieved using a 2-stroke piston bolt and a spring-loaded rammer.
Additional armament - three 7.62 mm DT machine guns, total ammunition of almost 2 thousand rounds. Location - at the stern and on the sides of the SPG.
The equipment included a 71-TK-3 radio station with an antenna for the production of external radio communications. Communication inside the tank went through the TPU-6 negotiators.
By the end of February 40 of the year, the armored hull was manufactured at the factory in just a couple of months after applying for an armored vehicle. And by the first March, everything was ready for the final assembly of the SPG. After 2 weeks, the SU-100Y was assembled and even began to carry out factory tests. But they did not manage to send the self-propelled unit for combat trials in the war with the Finns - on March 13, 40, hostilities on the Finnish front ceased. This became the point of no return for the SU-100Y.
Lacking combat experience, the SPG lost its place in the army to the KV-2 heavy tank. The KV-2 looked better than the SU-100Y:
- smaller dimensions;
- less weight;
- increased armor;
- economical diesel engine.
The only drawback of the KV-2 is the lower power of the 152.4 mm M-10 howitzer.
So the KV-2 went into mass production, and the SU-100Y self-propelled gun in the middle of 1940 was placed on a training ground near Kubinka, where it stood at the start of WW2.
Attempts by the designers of Plant No. 185 to give life to armored vehicles based on the T-100 continued. In April 40, they submitted a project for a tank for coastal defense. The project name is object 103.
According to the project, the tank had a rotating turret. An enlarged box was developed for it, but the dimensions of the turret did not increase compared to the SU-100Y.
The armament of the coastal tank was similar to the armament of the self-propelled gun.
Further consideration of the project did not go, and then the war began.
Main characteristics:
- number of copies - one;
- weight 64 tons;
- a team of 6 people;
- length 10.9 meters;
- width 3.4 meters;
- height 3.3 meters;
- armor - rolled steel;
- the length of the tool is 55 calibers;
- gun - 1-B-13 shipborne 130 mm;
- machine gun - three DT-29;
- GAM-34 engine;
- travel speed 32 km / h on the road;
- travel speed 12 km / h off-road;
- overcoming climbs up to 42 degrees;
- overcoming obstacles up to 130 centimeters high;
- overcoming depressions up to 400 centimeters;
- overcoming water obstacles up to 125 centimeters deep.
Possible use in WWII
There is information that when the German invaders approached the capital of the USSR in November 1941, a command was received to remove all operable equipment from the landfills and put it into operation to defend the capital.
According to the same data, the SU-100Y became part of the so-called "separate division of heavy equipment for special purposes." It is known that before this the SPG was brought into working order. Historical and documentary evidence of participation in hostilities of the only SU-100Y in WW2 has not yet been found.
After the threat of taking the capital of the USSR disappeared, the equipment (single copies) was returned back.
SU-100Y returned to the training ground near Kubinka, where it can be viewed to this day.
