Heavy self-propelled gun S-59 was developed in the design bureau of plant number 100. This vehicle was distinguished from the S-51 self-propelled guns by the installation of a 152-mm Br-2 gun. The gun was mounted on the chassis of the KV-1S heavy tank and was intended, first of all, to combat reinforced concrete fortifications. SPG was tested in May - June 1944, which could not stand it. After testing, the project was closed.