9 3 years ago, on October 31, 1933, the first tests of the underwater tank BT-5PH were carried out. The tests took place in the area of ​​the city of Borisov (Minsk region), the name BT-5PH stands for BT-5 underwater tank. A set of navigation equipment for the BT-5 wheeled tank was developed in the workshops of the 5th training battalion of the Belarusian military district. The tightness of the tank structure was ensured by the use of special rubber seals, and then additional painting of all joints and welds with red lead. The gun mask was sealed with an oil seal and a cover specially designed for this purpose. To seal the turret ring, a rubber tube with a diameter of 10-15 mm is used. Air was pumped into it with a manual pump until the excess pressure reached 2 kg/m2. With this solution, the tower kept the possibility of circular rotation without breaking the seal. For air supply and air emission, two steel pipes with a diameter of 300 mm and a height of 2 m were installed. A third pipe with a diameter of 200 mm was installed on the roof of the tower. During the tests, the BT-5PH covered a section along the Barzina river bed 40 m long and up to 4 m deep. Communication with the staff was ensured by landline phone.

9 3 years ago, on October 31, 1933, the first tests of the underwater tank BT-5PH were carried out. The tests took place in the area of ​​the city of Borisov (Minsk region), the name BT-5PH stands for BT-5 underwater tank. A set of navigation equipment for the BT-5 wheeled tank was developed in the workshops of the 5th training battalion of the Belarusian military district. The tightness of the tank structure was ensured by the use of special rubber seals, and then additional painting of all joints and welds with red lead. The gun mask was sealed with an oil seal and a cover specially designed for this purpose. To seal the turret ring, a rubber tube with a diameter of 10-15 mm is used. Air was pumped into it with a manual pump until the excess pressure reached 2 kg/m2. With this solution, the tower kept the possibility of circular rotation without breaking the seal. For air supply and air emission, two steel pipes with a diameter of 300 mm and a height of 2 m were installed. A third pipe with a diameter of 200 mm was installed on the roof of the tower. During the tests, the BT-5PH covered a section along the Barzina river bed 40 m long and up to 4 m deep. Communication with the staff was ensured by landline phone.