I.J.A. Tank Mech I-GA 4-leg Type

TheE-75 Heavy Mech Type Gis afirst-generation heavy combat mech, developed in1943as an experimental alternative to conventional armored vehicles. As one of the earliest mechanized war machines, it was designed to integratetraditional tank componentswithbipedal mobility, creating a new class of battlefield units. TheType Grepresents thefinal standardized iterationof the series, featuringimproved turret protection and a more ballistic-resistant design.

Development and Design

TheType Gwas part of a broaderheavy mech development program, initiated to create anassault unit capable of overcoming battlefield obstacles that traditional tanks could not. Since mech technology was still in its infancy, the design heavily relied onexisting tank components, such as itsengine, armor plating, and primary weapons. Thebipedal hydraulic systemwas introduced to enhancemobility in urban warfare and rough terrain, though it required extensive mechanical upkeep.

TheType Gfeatured a128mm high-velocity cannon, an evolution of battle-proven tank destroyer guns, allowing it to engageheavy armor and fortified positions. Fordefensive firepower, it was equipped withdual 30mm autocannons, mounted on the torso to counter enemy infantry and light vehicles.

One of the key refinements of theType Gwas itsrevised turret design, which incorporated amore ballistic-resistant shape, reducing weak points and improving crew survivability. This made it themost durable versionof theE-75 series, balancing firepower, protection, and battlefield adaptability.

First Combat Deployment (1943)

TheE-75 Heavy Mech seriessaw itsfirst combat deployment in 1943, achievingimmediate battlefield success. In its debut engagement, asingle unit recorded 10 confirmed kills, effectively neutralizingenemy tanks and defensive positionswhile withstanding significant counterfire.

The mechshigh-caliber weaponryandsuperior mobility over rough terrainallowed it todominate traditional armored formations, proving the viability of bipedal combat vehicles. Following its battlefield success, theproduction of E-75 units increased rapidly, leading to the manufacture ofover 2,000 unitsthroughout the war.

TheType Gemerged as thefinal and most refined variant, incorporatingimproved turret armorand astreamlined production process, making it themost widely deployed versionof the series.

Operational Role

Designed forfrontline assaults and defensive operations, theE-75 Heavy Mech Type Gwas often deployed as abreakthrough unit, capable of leading offensives and holding key strategic positions. Compared to traditional tanks, itsbipedal designallowed it to:

• Navigate difficult terrainmore effectively
• Engage from elevated positions
• Reposition faster in urban warfare

Itsheavy frontal armorenabled it to withstandanti-tank fire, while itsmodular turret configurationallowed for battlefield-specific weapon loadouts. However, itsmechanical complexityrequiredspecialized crews and maintenance teams, making logistics a challenge despite its effectiveness in combat.

Power and Mobility

The Type G is powered by a1,200-horsepower engine, adapted from existing tank powerplants. This allows it to reach atop speed of 45 km/h, making itrelatively mobile for its weight class. Itsbipedal hydraulic system, though mechanically complex, provides better adaptability inurban and rugged environments, where traditional tanks would struggle.

Crew and Protection

Unlike later mechanized designs, theE-75 Heavy Mech Type Grequired afive-person crew, similar to conventional heavy tanks. Thecrew members include:

• Commander Oversees battlefield operations
• Gunner Controls the primary weapon system
• Driver Manages movement and positioning
• Secondary Gunner Operates defensive weaponry
• Engineer/Operator Monitors mechanical systems and assists with in-field repairs

Thearmor protectionis among the strongest of its time, featuring a180mm-thick frontal plateandadditional reactive armor layers, allowing it to endure direct hits from enemy anti-tank weaponry. TheType Gvariant introduceda redesigned turret shape, improving itsballistic resistanceand reducing vulnerability toanti-mech fire.

Specifications

• Weight:65-70 tons
• Crew:5 (Commander, Gunner, Driver, Secondary Gunner, Engineer/Operator)
• Armor:180mm sloped frontal armor + reactive armor plating
• Primary Armament:128mm high-velocity cannon
• Secondary Armament:Dual 30mm autocannons
• Modular Turret Configurations:Multiple options for battlefield adaptation
• Power System:1,200 hp engine adapted from heavy tank designs
• Maximum Speed:45 km/h
• Mobility System:Bipedal hydraulic leg system for all-terrain adaptability
• Maneuverability:Optimized for breakthrough assaults and urban warfare
• Production Quantity:Over 2,000 units in total, with Type G as the final standardized model