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MS-05B Zaku I

Mass-produced general purpose mobile suit developed by the Principality of Zeon.
Jenxi Seow Published 23 Apr 2013 Updated 5 Feb 2025
MS-05B Zaku I

The MS-05B Zaku I was a mass-produced general purpose mobile suit developed by Zeonic for the Principality of Zeon. It was the first true mass-production mobile suit to see frontline service.

The “MS” in the type code indicated that it was a mobile suit. The “05” denoted that it was the fifth design of this type, and the “B” variant code identified it as the second version.

After the introduction of the Zaku II, which became commonly known simply as Zaku, the Zaku I earned the nickname Old Zaku among pilots.

History

Zeonic completed development of the MS-05B Zaku I in October UC 0077. A total of 793 units were produced before production shifted to the more advanced MS-06 Zaku II.

When the One Year War began in UC 0079, Zaku Is participated in the earliest stages of combat, including the devastating One Week Battle where they deployed nerve gas into colonies. As newer mobile suits entered service, most Zaku Is were reassigned to secondary roles like escort and garrison duty.

One notable engagement occurred on 8 May UC 0079, when a Zaku I guarding Zeon’s 67th supply depot in Arizona was destroyed by a Federation MS-06J Zaku II Ground Type. This marked one of the first recorded instances of mobile suit versus mobile suit combat.

During the Battle of A Baoa Qu, Zeon deployed all available units including the outdated Zaku Is alongside their latest mobile suits like the MS-14A Gelgoog.

After the war, some Zeon remnant forces continued using Zaku Is due to equipment shortages, with documented usage as late as UC 0096.

Design

The MS-05B was an improved version of the MS-05A Zaku I Early Type, featuring enhanced cockpit systems and superior armor materials. Its power transmission pipes were fixed and contained within the armor plating.

However, this internal power system design proved problematic—the pipes occupied significant internal space, making it difficult to upgrade the generator or replace components. The limb structures were also complex due to the internalized power system. These issues were later addressed in the MS-06 Zaku II series.

Armaments

The Zaku I’s standard weapons were machine guns for ranged combat and the Heat Hawk for melee engagements.

105 mm machine gun

This was the initial standard-issue machine gun for Zaku-type mobile suits. It used a 100-round drum magazine mounted vertically on the right side.

120 mm machine gun

The Zaku I used a 120 mm machine gun that later became a standard weapon for Zaku-type mobile suits. While it did not require energy to operate, its effectiveness against heavy armor was limited. Like the 105 mm version, it used a 100-round drum magazine.

280 mm Zaku bazooka

The 280 mm Zaku bazooka was specially designed for Zaku-type mobile suits. It fired explosive rounds and was primarily used for anti-ship combat in hit-and-run attacks. While effective against mobile suits, scoring hits on moving targets proved challenging.

Heat Hawk

The Heat Hawk was a close combat weapon with a superheated blade that could slice through enemy armor. The Zaku I typically used the Type 3 Heat Hawk, which was designed for anti-ship combat rather than anti-mobile suit warfare.

Some units were later upgraded with the Type 5 Heat Hawk used by the Zaku II series.

G-3 nerve gas grenade launcher

During the early phases of the One Year War, some Zaku Is were equipped with G-3 nerve gas grenade launchers. These launched rockets containing lethal nerve gas used to neutralize colony populations.

S-mine launcher

Anti-personnel explosive devices that could be fired from various points on the Zaku’s body. When detonated, they released a shower of metal fragments lethal to infantry.

Known pilots

  • Gadem – Piloted it during a resupply mission for Char’s forces
  • Topp – Piloted it during Zeon’s retreat from Odessa
  • Black Tri-Stars
  • Ramba Ral
  • Erik Blanke
  • Matt Austin
  • Gabby Hazard
  • Darmac Barlow

Variants

Behind the scenes

Okawara Kunio was the original mechanical designer for the Mobile Suit Gundam and MSV versions. Yamane Kimitoshi later redesigned it for Mobile Suit Gundam: The 08th MS Team and Mobile Suit Gundam: Requiem for Vengeance.

Appearances

Anime

Games

  • Mobile Suit Gundam: Bonds of the Battlefield
  • Mobile Suit Gundam Side Story: The Blue Destiny
  • Dynasty Warriors: Gundam
  • Mobile Suit Gundam: Battle Operation
  • Mobile Suit Gundam: Battle Operation 2
  • Mobile Suit Gundam: Extreme vs.

Manga

  • Mobile Suit Gundam Side Story: Space Beyond the Blaze
  • Mobile Suit Gundam: The Origin
  • Mobile Suit Gundam MSV-R