u/MAFIALAA

Fictional Historical Background:

In the early 1960s, the Space Race became the strategic high ground of the future. When the Soviet Union learned that the United States was secretly planning for lunar combat resources, it issued a top-secret directive: not only to be the first to land on the Moon, but also to be the first to establish a military defense system on the Moon to protect future Soviet lunar bases and outposts. "Object 790" came into being—this special tank was a heavy combat vehicle specifically designed for long-range patrolling, base defense, and fire support missions on the low-gravity, extremely harsh lunar surface.

Considering the low-gravity environment of the Moon, the design of Object 790 had to be redefined. The recoil of traditional tanks would severely affect shooting accuracy or even cause the vehicle to flip over. Furthermore, conventional fuel and oxygen are extremely precious resources on the Moon. The propulsion system posed the greatest challenge. The engineering bureau creatively abandoned internal combustion engines, opting instead to deploy a closed-cycle small nuclear reactor power unit named "Vostok-Atom-1" inside the hull. This compact hull was completely occupied by this nuclear power core, which not only provided a continuous stream of electricity for the tank's track propulsion, life support, and fully sealed turret operating systems, but also ensured the tank had a theoretically infinite operational range, eliminating dependence on costly fuel resupplies.

To maximize crew protection from radiation and extreme lunar temperature differentials, all three crew members (commander, gunner, and driver) were housed inside a fully sealed, heavily armored spherical turret. The driver operated the vehicle from within the turret via a specially designed remote electronic viewport located in the hull. The core weapon of Object 790 was a specially developed 110mm recoilless gun. By venting the counterforce of the propellant gases directly backward upon firing, it completely neutralized the forward recoil, allowing for omnidirectional firing in low gravity without compromising the hull's stability. Since all crew members were inside the turret, an autoloader was equipped at the rear of the turret to solve the loading issue. The front of Object 790 could withstand shells with 200–300mm of penetration, and the rear reactor was surrounded by vertical armor averaging over 250mm, designed to better protect the reactor core. The specialized track system was optimized specifically for the rugged rocks and low-traction environment of the lunar surface.

Object 790 underwent several successful trials at a secret underground testing ground within the Soviet Union that simulated the Moon's low-gravity and low-pressure environment. Although it demonstrated the robust power of its nuclear propulsion system and the precise firepower of its 110mm recoilless gun, it also possessed obvious drawbacks: the track system exposed the issue that repair and maintenance could not be performed as easily in a space environment as on Earth. However, with the postponement and ultimate cancellation of the Soviet lunar landing program in the late 1960s, the Object 790 project was shelved. In the end, it never set foot on the Moon.

If the Americans were the ones designing the Tiger tank... it would use an early cast hull, all rounded and plump, like a heavy tank version of the M4.

Fictional Historical Background:

With the victory of the war, the existing 152mm self-propelled guns (such as the ISU-152), though powerful, were still insufficient when dealing with deeply buried reinforced concrete fortifications, giant bunkers, and other strongpoints. The Stavka demanded a more powerful "city-buster." The design bureau of the Chelyabinsk Tractor Plant (ChTZ) was assigned this highly challenging task, codenamed "Object 510." Its core requirement was to motorize the largest mobile artillery piece in Soviet service—the B-4 203mm howitzer—enabling it to advance alongside armored units.

The B-4 203mm gun was a true heavy siege piece; its massive size and recoil meant it could not be mounted on any existing tank chassis. The design team had to reconceptualize. Instead of using the IS chassis, they developed a brand-new, widened, and lengthened heavy specialized tracked chassis and hybrid road wheels, specifically designed to support the gun's weight and absorb the recoil. To accommodate the massive B-4 gun and its high-elevation capability, the fighting compartment was designed to be fully open-topped, with only about 15mm of light armor plating installed on the front and sides. The greatest design challenge was managing the recoil of the 203mm gun. To this end, Object 510 was equipped with a massive hydro-pneumatic recoil system. Additionally, a massive, foldable hydraulic spade was installed at the rear of the vehicle to transmit the recoil directly to the ground.

By 1946, ChTZ had manufactured two Object 510 prototypes. Firing trials were conducted at a testing ground near ChTZ. While the destructive power of the 203mm gun was breathtaking, the vehicle's flaws were also obvious: even with the spade deployed, the massive recoil would slightly shift the vehicle, meaning recalibration was required after every shot. The 203mm ammunition was extremely heavy, requiring 3-4 crew members working together to complete loading; combined with the manual breech process, the rate of fire was restricted to an extremely low level. A specialized ammunition carrier was required to transport the shells. The open fighting compartment left the crew completely exposed to enemy fire, snipers, and the overpressure of the gun itself. Despite being tracked, its immense weight limited mobility. The complex transmission system also created logistical strain. With the development of missile technology and lighter, more flexible self-propelled artillery, the concept of a heavy open-topped siege vehicle was deemed impractical.

Nonetheless, the military still believed there was sufficient room for development, so the Object 510 project was only officially canceled in early 1950. A small number of production vehicles remained in service until retirement, eventually being replaced by lighter and more agile self-propelled artillery projects.

Fictional Historical Background:

In the summer of 1943, with the emergence of the Soviet IS-series heavy tank prototypes and the strengthening of Allied anti-tank fire, Germany realized that the existing Tiger I was overly conservative in its defensive layout (utilizing vertical armor) and that its firepower might soon reach a bottleneck. Consequently, the Army Weapons Agency issued a new tender to Krupp, requesting a design for a 60-ton vehicle capable of mounting Krupp’s own 10.5 cm heavy cannon.

The VK60.02(K)-Ausf.B featured a rear-mounted turret. To improve gunner visibility and gun elevation/depression, the turret ring was raised, and a specialized semi-open turret roof was utilized, allowing the tank to achieve superior depression angles. The frontal armor consisted of high-angle Rolled Homogeneous Armor (RHA); the upper glacis plate could withstand armor-piercing shells exceeding 250mm. This design allowed the 10.5 cm gun to be positioned at the rear of the vehicle to counterbalance the significantly heavier frontal armor. Due to the unique gun structure, the VK60.02(K)-Ausf.B was equipped with a custom autoloader system to enhance loading efficiency. During intensive testing in 1943, this prototype demonstrated staggering firepower. Its 10.5 cm main gun could penetrate all known Allied heavy tanks from a distance of 2,000 meters.

However, the drawbacks were equally apparent. Due to the unconventional turret design, crew protection was significantly compromised. The complex gun mechanism and immature autoloader occupied substantial internal space, resulting in a massive turret profile. This left the crew highly vulnerable to infantry and air strikes, while extremely limited visibility made it difficult for the commander to lead effectively. The overly ambitious and complex gun assembly also increased the risk of potential mechanical failure.

Project Evaluation and Termination:

Due to reliability issues, overly advanced concepts, and prohibitive costs, the VK60.02 project was terminated. However, the most decisive factor came from external competition. The VK45.03 (Tiger II) proposals from Henschel and Porsche were maturing rapidly and proved to be more pragmatic, utilizing existing supply chains. In late 1943, the Waffenamt (Ordnance Office) decided to shift focus entirely to the more reliable and production-ready Tiger II.

Fictional Historical Background:

In the summer of 1943, with the emergence of the Soviet IS-series heavy tank prototypes and the strengthening of Allied anti-tank fire, Germany realized that the existing Tiger I was overly conservative in its defensive layout (utilizing vertical armor) and that its firepower might soon reach a bottleneck.

At the time, Rheinmetall-Borsig was dedicated to developing its famous Waffenträger (Weapon Carrier) series. However, designers proposed a bold alternative: creating a mobile chassis with protection surpassing that of the Tiger, capable of direct-mounting the 128mm gun—originally intended for static fortifications or super-heavy tanks—all while maintaining a low profile and a combat weight under the 50-ton class.

This was the catalyst for the birth of the Rhm.B.HT. Its low-slung hull and compact dimensions kept its combat weight under 45 tons. By employing a highly sloped armor design (similar to the glacis of the Panther), the Rhm·B HT achieved an effective frontal defense of over 200mm despite weighing only 40 tons (barely heavier than a Panther). Its 128mm gun was capable of destroying any known Allied tank from a distance of 2,000 meters.



While the Rhm·B HT achieved a near-perfect balance in terms of raw data and performance, the cramped hull necessitated a custom-built engine, leading to poor parts commonality and exorbitant costs. Furthermore, the driver’s position to the left of the engine resulted in excessive cockpit temperatures during operation. Due to the insufficient horsepower of the specialized engine, the vehicle's overall mobility was poor; additionally, the production cost of the complex 128mm gun far exceeded that of the 88mm. Ultimately, as Germany favored the more massive and psychologically imposing "King Tiger," only ten Rhm·B HT prototypes were ever produced. Although they were all destroyed during the Battle of Berlin in 1945, they nonetheless posed a significant obstacle to the Soviet advance.

Fictional Historical Background:

While the original "Foch" project (based on the AMX 50 chassis and equipped with a 120mm gun) performed exceptionally in anti-tank roles, it was deemed somewhat lacking in power and range for destroying hardened fortifications or suppressing entire heavy tank platoons from extreme distances.

Consequently, the "Foch (H)" project was born. Based on an improved Foch tank destroyer chassis, it featured a lower profile and enhanced armor protection, enabling it to carry a large-caliber 150mm cannon. Due to the massive size of the shells, an autoloader was equipped to improve loading efficiency.

Despite the lowered hull, the oscillating turret required for the 150mm gun was so massive that it resulted in an excessively tall silhouette. Although the design provided ample firepower, it was ultimately abandoned for being out of step with the contemporary trend toward low-profile vehicles; consequently, only two complete prototypes were ever produced.

In my personal opinion, the Japanese might have opted for an improved, domestically-produced version of the 10cm gun, which would result in a relatively larger turret.

Fictional Polish super heavy tank destroyer.

A fictional Polish heavy tank project, weighing 68 tons and equipped with a 152mm gun.