RX-75-4 Guntank

By Jenxi Seow



RX-75-4 Guntank

The RX-75-4 Guntank was a prototype artillery mobile suit developed by the Earth Federation.

It was part of the Federation’s top-secret Project V, a programme initiated to research and build mobile weapons.


The Earth Federation begun the secret Project V to develop mobile weapons four years prior to the One Year War, after it received intelligence reports of the mobile suits that the Principality of Zeon was building.

The Guntank was the first model to emerge from the programme. It was designed for anti-mobile suit purposes to counter the potential threat of Zeon mobile suits. The mobility of the Zeon suits exceeded the expectations of the Federation scientists, resulting in a design that failed miserably in its intended purpose. However, the heavy fire-power of the Guntank meant that the time and money poured into the unit was a complete waste, as the Federation used the Guntank as an artillery unit.

The prototypes were deployed in the Federation’s research base in the colony Side 7 to undergo tests. All except one were destroyed in the attack by Zeon forces on the base. The last surviving Guntank served on the assault carrier White Base as a support unit between September and November UC 0079. During its time on White Base, the Guntank was upgraded from requiring a two-person crew to being operated by a single pilot.

The Guntank’s impact in the battlefront convinced the Federation to roll out a mass-produced version, the RX-75 Guntank mass production type.

In November UC 0079, the unit was decommissioned at Jaburo, the headquarters of the Federation Forces.

After the war, the Guntank was succeeded by the RMV-1 Guntank II.


The design of the RX-75-4 Guntank was inspired by a tank. The unit was intended for anti-mobile suit purposes, thus its main weapons were for medium and long range use.

The heavy weaponry mounted on the Guntank meant that humanoid legs were not a feasible as they would be unable to withstand the recoil. Caterpillar treads were used instead. This meant that the Guntank could not turn quickly. This impacted its its ability to aim its main cannons at moving targets.

Like the other units from Project V, the Guntank used the Core Block System that allowed the separation of the upper torso to continue operating as a fixed gun emplacement, while the Core Block functioned as an FF-X7 Core Fighter.

Due to the wide array of armaments available on the Guntank, it required a two-man crew consisting of a pilot and a gunman. The piloting and gunnery cockpits were so complex that they had to be separated into two: the pilot cockpit in the torso and the gunnery cockpit in the head. A better system was developed to allow the pilot to take over the gunning duties, and the Guntank was refitted with a single cockpit.

RX-75-4 Guntank cockpit

RX-75-4 Guntank cockpit


180 mm low-recoil cannons

A 180 mm cannon was mounted on each shoulder of the Guntank. These were used for long range artillery bombardment. The cannons had a firing distance of 260 km that was beyond visual range. Each cannon drew ammunitions from a 30-round magazine.

4-tube 40 mm Bop missile launcher
Two 4-tube 40 mm Bop missile launchers were mounted on the Guntank’s arms. They fired small anti-aircraft missiles with a range of 20 km. These launchers were the primary weapon of defence as the Guntank had no other close range armaments. The missiles were useful for providing cover fire against enemy support units but were less effective against mobile weapons.

Known pilots

Behind the scenes

Kunio Okawara was the original mechanical designer.

In the original Mobile Suit Gundam TV anime, the RX-75-4 Guntank was not decommissioned at Jaburo but continued service on board the White Base until it was destroyed at the Zeon space fortress A Baoa Qu, unlike in the compilation movie. This discrepancy was because the Guntank was seen as a super robot mecha and did not fit the real robot genre of the series. The events of the movie is considered as canonical as it is closer to Yoshiyuki Tomino’s vision of the series.


Non-canon appearances


Images from MAHQ.net