Comparing: Kirovets-1 vs. Löwe

The Kirovets-1 project (IS-3, prototype No. 1) was developed from July through November 1944. The prototype was built at the Chelyabinsk Kirov Plant in September–October 1944. From December 18 through December 24, 1944, the vehicle underwent trials at the NIBT proving grounds in Kubinka. After it was decided to manufacture a pilot series of the modified IS-2 with a hull proposed by engineers of Plant No. 100 and Сentral Research Institute-48, the work on the Kirovets-1 was discontinued.

Development of this 70-ton super-heavy tank started on November 1, 1941. In February 1942, the Krupp company suggested the VK 70.01 avant project, later designated the Löwe ("Lion"). Several designs varying in configuration, armament, and armor, were drafted. However, the project was canceled after the Führer made the decision to develop even heavier tanks. No prototypes were ever built.