Bizarre armor projects of the ’40s. Major Derkach’s “mobile fortress”

I guess that after the awesome 7-6 win NA’VI had (with the help of the magical rock), a translated historical article from Vlad will make you even more satisfied.

Let’s begin.

The saying of generalissimo A.V. Suvorov that the best defense is offense is known, but not undoubted. If this would be undisputable, the history of war wouldn’t have known any fortresses. For thousands of years, people hid behind their walls, enduring sieges and assaults. The 20th century came, which gave the war engines – and some minds thought: what if we make our fortresses move?

Guards’ major Derkach was a pilot in the 7th Rzhev Fighter Air Division of the 2nd Fighter Air Corps. However, he took on inventing a land vehicle with an enormous firepower. Its’ description arrived in fall of 1943 at the war council of the Red Army Air Force and was transmitted to the GABTU.

Absolute power on tracks

Firstly, Derkach outlined the “combat characteristics of the “Mobile Fortress”. He wrote:

“Thanks to its’ large area inside it is possible to place strong firepower, equivalent to one artillery and one infantry regiment…”

The inventor planned to arm his vehicle with 16 medium-caliber guns and 35-40 machineguns, and also with “means of chemical attack”. The main purpose of the “mobile fortress” would be breaking through heavily fortified enemy lines. At the same time, enemy fire couldn’t harm the destructive machine.

“Thanks to its’ form, it provides an almost invulnerable type of armor for any type of weaponry, excluding only the heaviest guns and only direct hits… Excluding the tracks which can be damaged by high-explosive ammunition”.

The “mobile fortress” could be a reliable machine for transporting troops and to disrupt communications in the enemy’s rear. Derkach promised an absolute terrain passability: “with its’ sharp hull, it can unroot almost all trees and move them aside”. Finally, his invention “will have a tremendous impact on morale, since no human can endure the sight of such a beast”.

The mass of the machine would’ve been 600 tons. It’s tracks’ surface area would be about 100 square meters. Additionally, the author considered adding “idle” tracks at the front and back to prevent the fortress from bogging down in muddy ground. “Additional tracks are supposed to scarify the ground in front and even out any earth walls in front” – Derkach wrote.

The vehicle’s crew was counting 105 men, which isn’t surprising considering the proposed armament. Even in the most vulnerable parts of the hull, the men and guns were portected by three layers of armor with a thickness of at least 220mm. The inner layer would consist of armor plates in a way that “they would form an integral egg-shaped layer”; the middle part made of rubber would lay directly on the inner one. And the surface of the “mobile fortress” would consist of “single armored, semi-raised patches, which would lay one on another with one end (like fish scales)”. But that’s not all: Derkach also proposed to place 10-12 spiral springs between a “scale” and the body to absorb the hits of enemy shells.

The movement would be provided by four diesel engines using heavy fuel – Derkach proposed to use crude oil thinking this would reduce the risk of fire to almost zero.

Afterwards, the author admitted that he lacks the technical knowledge to provide details for his project. He was proud of the general idea and also provided drawings of the “mobile fortress”.

Experts’ evaluation

The engineers of the inventions department studied Derkach’s project. Their answer was on point as was the description of the project’s advantages by the author.

First of all, engineer Frolov pointed out that the development of such a machine will be connected to severe production difficulties. It would entail large material costs. During the Great Patriotic War, this was a solid argument against even more realistic proposals.

Furthermore: moving the “mobile fortress” by rail wouldn’t be possible. It couldn’t cross bridges which already gave up at the weight of the German “Ferdinand”, having ten times less mass than the “fortress”. Thus, water barriers weren’t passable for Derkach’s vehicle.

The armor protection praised by the inventor was nullified by the vulnerable chassis. If such a superheavy tank was to be immobilized, it couldn’t be towed from the battlefield to the depot of damaged tanks. And on-field repairs were not easier. The immobile “fortress” would be an easy target for enemy artillery and bombs. “From a tactical point of view, the usage of such a type of tanks would not be beneficial. As of the stated reasons, the proposal is rejected” – the experts noted.

In fairness, major Derkach was not the only one with such enthusiasm and such misconceptions. A similar project is known – the German breakthrough tank “Ratte”, weighing 1000 tons. It contained a number of shortcomings similar to the mistakes of the “mobile fortress”. In the USSR, there were similar porposals before and after this one. But the ideal means of defense and offense remained in form of the ordinary tank.

Author – Yuri Bachurin

Source: Central archive of the Ministry of Defense of the Russian Federation (ZAMO RF)