The design of the chassis is still feeling the effects of the French school. The chassis consisted of eight rollers (on one side) that were mutually interlocked in four carts with vertical spring cushioning, support rollers 4, the front of the guide and the rear drive wheels. The work progressed rapidly, but at the finish the assembly stage, the tank configuration were made. Nonahedral main tower, its layout has already been installed on the reference swatch, was changed to a cylindrical having a direct frontal sheet. Instead engine Hispano, had to set up the Russian Mikulino engine design, the creation of which had yet to do in Leningrad factory "Bolshevik." Of course, it could not get in time, because as a substitute was offered M-6 aircraft engine with a power of 180-200 hp In this regard had to redo a box shifter and floating band brakes designed Zaslavsky. Planetary gear made it possible to change the running mode to 2.7 and 15.7 km / h, while maintaining the ability to reverse all speeds. T-12 was a very long body, in order to overcome the trenches and ditches equipped with its "tail" which lengthened by 690 mm tank. Thickness of the frontal armor plates was 22 millimeters board — 12 millimeters. Atypical for the Russian tank development was placing the workplace of the driver, who was at the right side.
The construction of the most experienced tank benchmark was conducted on 15.10.1929 to 10.13.1928 was, but in his final equipment necessary equipment and rework spent another two months. In February 1930 accomplished acceptance of the tank, but the tests he was given only the second of April. The report RGVA indicated that the standard of the most experienced tank T-12 (Which has no weapons) was only 2 kilometers Myagenko on the ground and braked due to damage box. Unstained while the motor was equal 33 minute time frame, of which 21 minute moving. After repairing the tank again began sea trials. Pretty quickly became clear that the chassis of the T-12 flawed. CAT overheat, boil the water in the radiator, in the second denied rate, and the right track comes off while turning on Myagenko ground. At the same time, the T-12 showed better smoothness. To evaluate the new tank in the period from 28.04 till 02.05 in 1930 attended the tests Voroshilov — People's Commissar, Khalepsky — Head of UMM and Bokis — Head of Tech. Management UMM also Vladimirov Makhonin representatives from KhPZ. Who is the most experienced tank T-12 has shown its highest capacity. Cross Country tank moved quickly, with all this in first gear, he mastered the rise of 35-36 degrees. The hard ground speed was 26 km h, but with increasing speed up to 2 thousand for the moment she went up to 30 km h The machine effortlessly overcame a two-meter trench on the sandy ground, although it is estimated he could overcome trench widths up to 2.65 meters. Specific pressure during the dive track chains with 100 mm Myagenko ground equated with 0.45 kg / sm.kv..
Firing tests to completely failed. In the absence of the machine gun Fedorov ball mount Shpagin mounted 7.7-mm machine gun Lewis. Shooting of this gun gave positive results — the target on the go has got about 60% of the bullets. Accuracy of 45-millimeter cannon design Sokolov failed to hold, as it was not ready. The gun on a tank installed in the summer of 1930, and from July 12 to continue the test T-12 Equipped with this weapon. Full tank ammunition was equal shot 100 and 4,000 rounds of ammunition, but when you install a full set of weapons he was up to 98 rounds and 7,200 rounds of ammunition. Along with this great shooting 22 — and 18-mm armor plate of the tank showed that the body armor presented for it corresponds to the requirements of one hundred percent. In general, previous shortcomings have given a point to know. As before, the right track gets lost due to soil adhering to the steering wheel, the transmission rate of arbitrarily dumped after 20 operations, and after using up 30 liters. it ceased fuel flow to the engine, though still in the tank was 130 l. The State Commission has remained generally satisfied with the tank, but recommended a revision T-12 — First mentioned in store small door "maneuver the tank." Some observations have been corrected on a modified T-24 tank, batch creation of which began in 1932.
Technical properties of the T-12:
Combat weight — 14700 kg;
Crew — 4 people;
Length — 6282 mm;
Width — 2810 mm;
Height — 2950 mm;
Ground clearance — 500 mm;
Armament — 45-millimeter cannon standard in 1930, three 7.62-mm machine gun DT;
Ammunition — 98 rounds, 7,200 rounds of ammunition;
Aiming devices — optical gun sight;
Forehead hull and turret — 22 mm;
Aboard the hull and turret — 12 mm;
Engine — M-6, 8-tsilinrovy, carburetor, power 180 hp at 1500 rpm min;
Box — mechanical. It consisted of the main clutch disc dry friction, planetary gearbox, which has a floating band brake, dual differential and single-board transmission, 5-speed gearbox;
Chassis — part of the 1st board included eight double rollers having a counterweight suspension, 4 double support rollers, drive gear, with a garden and located the steering wheel, which has a crank mechanism of tension;
Road speed — 26 km h;
The stores range — 80 km.