Bizarre armor projects of the '40s. SIG Tank Destroyer

Time for another historical article translated by Vlad.
The history of constructing a one-man combat vehicle has it’s roots at the end of the 19th century. In the years between the World Wars, it was picked up by tankettes which were fancied by all somewhat developed armies. But the popularity of compact one- or two-man vehicles vanished quickly, since their combat capabilities left much to be desired.
But the inventors didn’t stop. And even during the years of WWII, projects of one-man mobile emplacements kept arriving at the department of inventions. One of these was the tank destroyer “SIG” authored by engineer S.I. Galperin from Votkinsk.
The arrangement of the destroyer
Compared to other whimsical and oftentimes unrealizable projects, Galperin’s vehicle, which arrived at the GABTU in December 1942, had a high level of detail.
The “SIG Tank destroyer” should represent a sphere with a frontal armor thickness of 40mm, side and rear armor of 20mm and bottom armor of 16mm. Galperin assumed that this would provide defense of his machine against bullets and shrapnel of every caliber and also against anti-tank guns of up to 37mm at a distance of 100m.


Galperin considered that his machine would be highly mobile. Thus, the maximum speed even on muddy ground would be up to 120 km/h provided by an engine with 200 HP, installed on spring absorbers in a special recess on the bottom. The height of obstacles to be overcomed by the “destroyer” was 0.6m at an elevation angle of 50°.

The chassis of the “SIG” looked like a huge wheel with the diameter of 1.75m whose rim symmetrically split the body. A small pair of wheels at the rear part was meant to turn the vehicle. Galperin used the system of the “Tsar Tank” of 30 years ago without knowing it himself. The latter had a similar system with rear wheels used for turning attached to the main body.
Armed to the teeth

Reasoning about the combat capabilities of his destroyer, the inventor wrote: “Having a quite higher maximum combat speed and tactical maneuverability that opposed German tanks, the destroyer can surprise enemies from the rear and hit a tank from a distance of 30-10m”.
Along with this, Galperin proposed to use his machine to fight mechanized units of the enemy, to demoralize and destroy manpower, including cavalry, and also to “suppress gun emplacements by firepower and weight”. The inventor considered a mass of 2.5 tonnes enough for this task.
The author didn’t spare firepower for his vehicle. He proposed to install an anti-tank gun, grenade launcher, flamethrower and a machinegun. Such abundance was accompanied by some specifics regarding the arrangement and steering.
For example, Galperin suggested to provide compulsory rotation of the gun barrel after each shot – how and why was not explained however. The gun was to be aligned vertically by “swinging the steering wheel up and down respectively”. The horizontal alignment was not provided, neither for the gun nor for the grenade launcher – they were fixed along the body, similar to a tank destroyer. A reloading mechanism was not described by Galperin, he only specified that the magazine of the grenade launcher had to be replaced manually.
The flamethrower was a small gas cylinder with inflammable mixture inside which was feeded into the barrel to create a flame jet. It was paired with a machinegun. It wouldn’t have been easy to manage this arsenal for one single man. But the inventor self-confidently thought: “the steering and firing operations are brought to a minimum”.
Specialist’s estimate
The author was confident in the superiority of his “tank destroyer SIG” over the enemies’ vehicles regarding the firing rate: “The German medium tanks of type III and IV have a manual turret rotation control and, as such, allow a turning rate of only 10°/s”. The key to success was the usage of a multitude of Galperin’s machines in combat to cover each other.
But it is rightly pointed out by Y. Pasholok that “besides a progressive construction and advanced weaponry, Galperin’s tank destroyer also had many shortcomings…”. The driver of this vehicle had to execute all tasks of a tank crew. Galperin also didn’t provide intelligible information about any observation devices, and the provided vision slots were clearly not enough to oversee the surroundings. Finally, there was no engine suited for the “SIG” by power and dimensions, so Galperin’s proposal was rejected in the end.
For all the strangeness of the project, it should not be spoken to ironically of. It was, similar to many other projects, a sign of the times. Galperin expressed his vast experience and knowledge about combat vehicles on paper, and his idea did not lack originality. The fact that many similar projects remained on paper is explained by a common fault of their design. It was named by the tank-automotive management of the Red Army in the ’30s: “The difficulty of operating a machine and overviewing the field of battle for a single individual, let alone the possibility of firing…”. The return to this concept was only allowed by automatization of firepower controls.
Author – Yuri Bachurin
Central archive of the Ministry of Defense of the Russian Federation (ZAMO RF)
Russian State Military Archive
Pasholok Y.I. “Stalin’s steel spheres. Construction and production”