MS-05 Zaku I

By Jenxi Seow



MS-05 Zaku I

The “MS” in the model code indicated that it was a mobile suit. The “05” in the model code indicated that it was the fifth line of mobile suits Zeon developed.


Early Type

In the late UC 0070s, the Principality of Zeon embarked on an ambitious mobile weapons development programme as part of its aggressive militarisation in preparation for war with the Earth Federation to gain independence.

The MS-04 Bugu was the first mobile suit to emerge from the mobile suit project in February UC 0074. However, the design was too expensive for mass production. Zeon engineers stripped the Bugu of its complex and expensive equipment and to derive the MS-05A (YMS-05) Zaku I Early Type in August UC 0074. The Zaku I Early Type initially used the YMS-05 designation to indicate it was a prototype, but switched to the MS-05 model code when it went into mass production.

The Zimmad Company, one of Zeonic Company’s competitors, produced the EMS-04 Zudah that was superior to the Zaku I Early Type. However, the Zudah disintegrated during a trial. Despite its poorer performance, the Zaku I Early Type was selected for mass production as it proved to be more stable than the Zudah. Regardless, a rumour that politics played a part in the Zeonic Company winning the tender continued to make rounds in Zeon.

B Type

To differentiate the Early Type from the improved version, it was referred to as the MS-05A, while the refined version of the Zaku I used the model code MS-05B. Initially referred to as the B Type, it was more commonly simply called the Zaku I.

Zeon produced 27 units of the Zaku I Early Type in May UC 0075. The pioneer batch of Zeon mobile suit pilots, including Ramba Ral, Gaia, Ortega, Mash tested them in the field. Zeon engineers used the data collected to develop the improved MS-05B Zaku I.

The four units of the Early Type piloted by Char Aznable and the Black Tri-Stars saw action during the Battle of Mare Smythii in UC 0078. The Zaku I units put on a display of might by wiping out all twelve mobile suits of Iron Cavalry Squadron that the Earth Federation deployed.

The initial batch of mass-produced Zaku I units rolled out in July UC 0077. The Zaku I enjoyed a production run of 793 units before it was succeeded by the MS-06F Zaku II as Zeon’s mainstay mobile suit.

One Year War and beyond

When the One Year War begun, the Zaku I was five years old and considered an obsolete model. It saw limited action with auxiliary duties such as training, construction and supplies transportation.

The Zaku I was infamously used in Operation British where Zeon forces gassed the inhabitants of Side 2’s Hatte colony, and attached boosters to drop it on Earth with the Federation’s Jaburo base as its intended target. Zeon’s Special Forces helmed by Kycilia Zabi deployed in Zaku I units in the battle to seize Granada.

Zeon also fielded many Zaku I units in the Battle of Loum. In the closing months of the war, after Zeon suffered defeats in Operation Odessa and Operation Star One, Zaku I units saw action when they deployed in the front lines to reinforce the faltering Zeon forces. They were often used as rearguards and to hold positions.

In December UC 0079, Daryl Lorenz of the Living Dead Battalion piloted a Zaku I unit when stationed in the Thunderbolt Sector in the ruins of Side 4. Several units were also used when the Midnight Fenrir Corps defended the California Base. The Zaku I also served in Zeon’s last stand in A Baoa Qu.

After the war, the Zaku I continued to see action with the Zeon Remnants up to UC 0096. Darmac Barlow piloted a modified unit when the remnants attacked the Earth Federation during the ceremony to commemorate the end of the One Year War.

Production overview

Model number: MS-05

Code name: Zaku I

Type: Mass production ground combat mobile suit


  • May UC 0075 (MS-05A)
  • October UC 0077 (MS-05B)

First deployment:

  • July UC 0077 (MS-05A)
  • October UC 0077 (MS-05B)

Manufacturer: Zeonic Company

Operator: Principality of Zeon

Developed from:

Developed into:


  • MS-05L Zaku I Sniper Type
  • MS-05S Zaku I Commander Type
  • MS-05 Zaku I Thunderbolt Sector
  • MS-05 Zaku I Ramba Ral Custom
  • MS-05 Zaku I Black Tri-Star Custom
  • MS-05 Zaku I Char Aznable Custom
  • MS-05 Zaku I Kycilia’s Forces Custom
  • MS-05 Zaku I Erik Blanke Custom
  • MS-05 Zaku I Darmac Barlow Custom

General characteristics

Crew: Pilot only

Cockpit: Standard cockpit in torso

Head height: 17.4 m

Total height: 17.5 m

Empty weight: 50.3 t

Gross weight: 65.0 t

Armour: Super hard steel alloy

Sensors: Standard

Sensor range: 2,900 m


Power plant: Minovsky type ultracompact fusion reactor

Power output: 899 kW


  • Rocket thrusters: 2 x 19,500 kg, 2 x 850 kg

Max speed: 120 km/h

180° turn time: 2.9 s

Thrust-to-weight ratio: 0.63 G




  • 1 x 105 mm machine gun
  • 1 x 120 mm machine gun
  • 1 x 280 mm Zaku bazooka
  • 1 x Heat Hawk Type 3
  • 1 x shotgun
  • 1 x grenade launcher
  • 1 x cracker grenade
  • 1 x bazooka type A1
  • 1 x bazooka type A2
  • 1 x anti-space ship rifle


In order to make the mobile suit feasible for mass production, the Principality of Zeon simplified the design of the MS-04 Bugu to derive the MS-05A Zaku I Early Type by stripping away expensive and complex features. The Zaku I Early Type had reduced mobility compared to the Bugu as a result.

After testing the Zaku I Early Type, Zeon engineers used the data collected to develop the improved MS-05B Zaku I. The Zaku I had poor performance, something made more evident after it was outperformed by the EMS-04 Zudah. It was only the disintegration of the Zudah during the trials that convinced Zeon to use the Zaku I as the mass-produced front line unit.

The Zaku I Early Type had low Minovsky power plant output. Zeon engineers addressed this issue by increasing the output for the Zaku I. However, as the cooling pipes of the Zaku I were built under the armour, they were inefficient in dissipating heat. This limited the output the engineers could coax out of the reactor.

Aware of the Zaku I’s shortcomings, the Zeonic Companydesigned the MS-06A Zaku II Early Type that had strengthened cooling pipes that could be exposed outside the armour. This improved heat efficiency and allowed the Zaku II to mount a more powerful generator.

The Zaku I had super hard steel alloy armour. The Zaku I Early Type had two rocket thrusters with output of 19,500 kg each. The Zaku I had two additional thrusters with output of 850 kg each. This gave the Zaku I a combined propulsion output of 40,700 kg and improved manoeuvrability.

The Zaku I had a standard cockpit in its torso. The cockpit was an improved version over the one in the Zaku I Early Type. Its standard sensors gave it a detection range of up to 2,900 metres.


The Zaku I did not have any fixed weaponry. It could use ranged and melee handheld weapons.

105 mm machine gun

The standard weapon for Zaku I Early Type was a 105 mm machine gun. It was drum-fed with 100 rounds per drum. Spare drums were usually stored on the suit’s waist armour racks.

120 mm machine gun

The ZMP-47D/120 mm machine gun replaced the 105 mm machine gun as the Zaku I’s standard weapon. Like its predecessor, it was also drum-fed with 100 rounds per drum. It did not require power to be fired. However, that reduced its effectiveness against heavy armour.Spare drums were usually stored on the suit’s waist armour racks.

Its use under gravity was initially a cause of concern as it was developed for use in space. There were no issues reported about its usage on Earth.

280 mm Zaku bazooka

The H&L-SB21K/280 mm A-N bazooka was an artillery armament that fired explosive rounds. It was designed for use against enemy ships.

It used four-round magazines and spare magazines were stored on the side hip armour. The bazooka was clasped on the rear waist armour when not in use.

Heat Hawk Type 3

The Heat Hawk was a melee weapon designed for the Zaku I. It was an axe with a super-heated metal blade that could melt armour as it cut. The Heat Hawk drew power from a battery that recharged when stored.

It was mainly used in close combat or against enemy ships. The Heat Hawk was clasped on the rear armour when not in use.


The shotgun was a ranged weapon designed for assault load out. It had a nine-round capacity and could use several types of ammunitions, including slingshot, buckshot and birdshot.

Grenade launcher

Zeon developed the G-3 nerve gas grenade launcher specifically for Operation British. They fired rockets filled with lethal G-3 nerve gas.

Cracker grenade

The MIP-B6 cracker grenade was an explosive weapon designed for the Zaku I. It was thrown and detonated after a set amount of time, breaking into smaller munitions that spread over a wide area.

Bazooka type A1

The bazooka type A1 was a rocket launcher designed for the Zaku I. It was mainly used for anti-ship combat. The bazooka carried only one rocket and had to be reloaded after each shot.

Bazooka type A2

The bazooka type A2 was a rocket launcher used for anti-ship combat. Unlike the A1, it used a three-round magazine. Spare magazines were carried on the suit’s waist armour racks.

Anti-space ship rifle

The Zaku I used the ASR-79 rifle mainly in anti-space ship combat. Its bullets scattered pellets after penetrating the ship’s hull to destroy the ship from the inside. It was highly effective when fired into the ship’s bridge or engine.


The Zaku I had a few variants with non-standard weapons load out and modifications for special purpose or missions.

It was also common for high-ranking officers and ace pilot to have customised mobile suits during the One Year War.

  • MS-05 Zaku I Ramba Ral Custom
  • MS-05 Zaku I Black Tri-Star Custom
  • MS-05 Zaku I Char Aznable Custom
  • MS-05 Zaku I Kycilia’s Forces Custom
  • MS-05 Zaku I Erik Blanke Custom
  • MS-05 Zaku I Darmac Barlow Custom

MS-05 Zaku I Thunderbolt Sector

During its time in the Thunderbolt Sector in the ruins of Side 4, the Living Dead Battalion deployed a custom Zaku I unit. As a worker unit converted for combat use due to a shortage of mobile suits, it retained an orange paintwork. Due to the sheer amount of debris, the Zaku I had sealed joints to protect them from small debris.

It featured a larger backpack with a propellant tank for increased manoeuvrability among the floating space debris. The backpack had a claw arm to hold extra weapons or move space debris. The Zaku I had feet with modified soles that could attach to debris.

MS-05B Zaku I Ramba Ral Custom

Test pilot Ramba Ral painted his Zaku I unit blue. His prowess in the Zaku I earned him the nickname Blue Giant Star.

MS-05B Zaku I Black Tri-Star Custom

Ramba’s subordinates and fellow test pilots Gaia, Ortega, and Mash were known as the Black Tri-Stars. Their Zaku I units had custom black and purple paint. Both Gaia and Ortega preferred the machine gun as their ranged weapon of choice, while Mash used a bazooka. The trio practiced coordinated attacks that gave them an edge in battle.

MS-05B Zaku I Char Aznable Custom

Char Aznable piloted a Zaku I unit painted red. He chose to use suit without the limiter that protected the pilot from excessive G-force to get the maximum response from it. The incredible speed of the mobile suit coupled with his piloting mastery earned him the nickname Red Comet as he seemed to move three times faster than the standard suits.

MS-05B Zaku I Kycilia’s Forces Custom

The Zaku I units used by the Special Service led by Kycilia Zabi had a darker colour scheme compared to the standard green. The Zaku I Kycilia Forces Custom had a crest on its head, in the style of the helmet worn by the Munzo State Security Police cavalry.

MS-05B Zaku I Erik Blanke Custom

Erik Blanke from Zeon Remnants group Invisible Knights piloted a custom Zaku I unit. In UC 0081 It was painted purple and had spikes on its left shoulder armour piece. Instead of the standard Heat Hawk, it wielded a Heat Sword designed for the MS-07B Gouf.

MS-05B Zaku I Darmac Barlow Custom

Zeon Remnants pilot Darmac Barlow deployed in customised Zaku I in UC 0096. The suit featured a modified knuckle shield for melee combat, and shoulder shields with additional hard points for attaching more weapons than the standard load out.

Behind the scenes

Kunio Okawara was the original mechanical designer. He created the versions in Mobile Suit Gundam and Mobile Suit Variations. Kimitoshi Yamane designed the version in Mobile Suit Gundam: The 08th MS Team.

Tomino’s Zaku idea sketch