The t 37a was a soviet amphibious light tank the tank was first created in 1932 based on the british vickers tankette and other operational amphibious tanks the t 37a was the first series of mass produced fully amphibious tanks in the world in the red army they were used to perform tasks in communication reconnaissance and as defence units on the march as well as active infantry support on the battlefield the t 37a were used in large numbers during the soviet invasion of poland and in t