The CN08 (Cannon 08) is a 120 mm 55-caliber

smoothbore A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. Some examples of smoothbore weapons are muskets, blunderbusses, and flintlock pistols. ...

tank gun produced by

Hyundai WIA Hyundai WIA Corporation (), formerly known as WIA (World Industries Ace; ) is a member of the Hyundai Motor Group and is the second biggest automotive parts manufacturer in South Korea. As one of the core companies of Hyundai Motor Group, it i ...

. It is incorrectly known as the licensed production of the Rheinmetall Rh-120 L/55, but it was indigenously developed by the

Agency for Defense Development The Agency for Defense Development (ADD, ) is the South Korean government agency for research and development in defense technology, funded by the Defense Acquisition Program Administration (DAPA). It was established in August 1970 under the ban ...

and WIA (now Hyundai WIA) from 2003 to 2008 for the XK2 development project started in 1995. The development was completed after the field test ended in September 2008.

Design

The CN08 is the main armament of the

K2 Black Panther K2 Black Panther () is a South Korean List of main battle tanks by generation#Fourth Generation, fourth-generation main battle tank (MBT), designed by the Agency for Defense Development and manufactured by Hyundai Rotem. The tank's design bega ...

, and the

gun barrel A gun barrel is a crucial part of gun-type weapons such as small arms, small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high ...

is applied with internal

chrome plating Chrome plating (less commonly chromium plating) is a technique of electroplating a thin layer of chromium onto a metal object. A chrome plated part is called ''chrome'', or is said to have been ''chromed''. The chromium layer can be decorativ ...

technology for the large-caliber gun. The gun barrel can endure a high explosive force as a result of the increased

stiffness Stiffness is the extent to which an object resists deformation in response to an applied force. The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is. Calculations The stiffness, k, of a ...

and

wear Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology. Wear in ...

resistance provided by this internal chromium surface. The main components, including the breech ring,

breech block A breechblock (or breech block) is the part of the firearm action that closes the breech of a breech loading weapon (whether small arms or artillery) before or at the moment of firing. It seals the breech and contains the pressure generated by th ...

and

thermal sleeve A thermal sleeve, or blanket, is a device around the length of a gun barrel of a large caliber gun, typically found on modern tanks. Its primary purpose is to provide a more consistent temperature to the gun barrel, preventing distortions due to ...

, are simplified and designed lightly, the gun barrel weighs and the gun mount weighs . The gun mount is composed of an eccentric hydro-pneumatic recoil system with

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

reservoir for the gun barrel and is complemented by a bustle-type

autoloader An autoloader or auto-loader is a mechanical aid or replacement for the personnel that load ammunition into crew-served weapons without being an integrated part of the gun itself. The term is generally only applied to larger weapons, such as na ...

switched reluctance motor The switched reluctance motor (SRM) is a type of reluctance motor. Unlike brushed DC motors, power is delivered to windings in the stator (case) rather than the rotor. This simplifies mechanical design because power does not have to be delivere ...

(SRM) combined with a breech controller that automatically opens and closes the gun tube, and it can fire up to 10 rounds a minute. The maximum permissible

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

of the gun barrel is 744 MPa (108,000 psi), and when the

tank gun A tank gun is the main armament of a tank. Modern tank guns are high-velocity, large-caliber artilleries capable of firing kinetic energy penetrators, high-explosive anti-tank, and cannon-launched guided projectiles. Anti-aircraft guns can also ...

fires an improved K279

APFSDS Armour-piercing fin-stabilized discarding sabot (APFSDS), long dart penetrator, or simply dart ammunition is a type of kinetic energy penetrator ammunition used to attack modern vehicle armour. As an armament for main battle tanks, it succeeds arm ...

, the maximum proof pressure is , and the

muzzle velocity Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/ shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately t ...

is . It depends on the type of ammunition, but the effective firing range of the tank gun is .

Dynamic muzzle reference system

The main armament has a dynamic

muzzle reference system A muzzle reference system (MRS) is a device used on most modern tank guns and some artillery systems that measures the bending of the barrel due to heat, gravity and other issues. It normally consists of a laser A laser is a device that e ...

(DMRS) consisting of a laser reflector, a laser emitter and a vertical sensor unit (VSU). A laser reflector assembly attached to the top of the thermal sleeve is provided to be adapted to a dynamic muzzle reference system to electro-optically measure the accurate position of the muzzle. The mechanical gyroscope type vertical sensor unit, which calculates the

lead angle Lead is the axial advance of a helix or screw during one complete turn (360°) The lead for a screw thread is the axial travel for a single revolution. ''Pitch'' is defined as the axial distance between adjacent threads on a helix or screw. In ...

and superelevation in real time to correct the misalignment of the aim, allows the tank to more accurately hit its intended target even when it is maneuvering on irregular

terrain Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...

Ammunition

K279 APFSDS-T and K277 HEAT-MP-T of Poongsan Corporation

CN08's 120 mm round is produced in

Poongsan Corporation Poongsan Corporation () is a South Korean manufacturer of copper and alloy materials, ammunition and precision forging products founded in 1968. The company's main business areas are non-ferrous metal processing, such as bi-metallic coins and cop ...

, a South Korean ammunition manufacturer, and can fire 120×570 mm NATO tank ammunition.

Export

Turkey

On July 29 2008,

Hyundai Rotem Hyundai Rotem Company, often referred to as Hyundai Rotem (), is a South Korean manufacturer of railway rolling stock, railway signalling, defense products and plant equipment. It is a member of Hyundai Motor Group and has presence in more than ...

and

Otokar Otokar Otomotiv ve Savunma Sanayi A.Ş., also known simply as Otokar, is a Turkish bus and military vehicle manufacturer headquartered in Sakarya, Turkey. Otokar is a subsidiary of Koç Holding. History Otokar was founded in 1963 as Turkey' ...

signed a contract for technology transfer and design assistance for the

Altay Altai or Altay may refer to: Places *Altai Mountains, in Central and East Asia, a region shared by China, Mongolia, Kazakhstan and Russia In China *Altay Prefecture (阿勒泰地区), Xinjiang Uyghur Autonomous Region, China *Altay City (阿勒� ...

Tank Development Project. This contract includes technology transfer and design assistance for systems, armor package, and 120 mm guns required for

tank development.

Poland

On July 27, 2022,

Polish Armaments Group The Polska Grupa Zbrojeniowa or PGZ SA ( English: ''Polish Armaments Group'') is a holding company established by the Polish government in 2013 to unite Polish state owned defence industry companies. Headquartered in Radom, the group is Poland's ...

(PGZ) and Hyundai Rotem signed a

framework agreement In the context of negotiations, a framework agreement is an agreement between two parties that recognizes that the parties have not come to a final agreement on all matters relevant to the relationship between them, but have come to agreement on en ...

to supply 180 K2s and 820 K2PLs. The agreement will include rapid arms supply and extensive

technology transfer Technology transfer (TT), also called transfer of technology (TOT), is the process of transferring (disseminating) technology from the person or organization that owns or holds it to another person or organization, in an attempt to transform invent ...

from South Korea, and 180 K2s will be produced in South Korea and delivered to Poland from 2022, and 820 K2PLs will be produced in Poland under license from 2026.

Variants

MKE 120 mm gun The MKE 120 mm gun is a Turkish 120 mm 55 caliber smoothbore gun based on the CN08 120 mm gun produced by the Turkish company Mechanical and Chemical Industry Corporation, used on the Turkish Altay tank. The gun has a length of . The gun can fir ...

: Turkish 120 mm 55 caliber smoothbore gun modified based on CN08 for the Altay tank. The design of the tank gun is the same as CN08, but there are two differences: unlike CN08,

is equipped with Static Muzzle Reference System (SMRS), and Altay's turret does not have breech opening motor and automatic feeding magazine system for autoloader mechanism, so ammunition can only be loaded manually by tank crew and can fire up to 6 rounds a minute.

Operators

Current operators

* –

Polish Land Forces The Land Forces () are the land forces of the Polish Armed Forces. They currently contain some 110,000 active personnel and form many components of the European Union and NATO deployments around the world. Poland's recorded military history str ...

* –

Republic of Korea Army The Republic of Korea Army (ROKA; ), also known as the ROK Army or South Korean Army, is the army of South Korea, responsible for ground-based warfare. It is the largest of the military branches of the Republic of Korea Armed Forces with 365,0 ...

Notes

References

External links

{{Commons category, CN08 120 mm gun
Principle of hydraulic recoil mechanism of CN08
120 mm artillery Tank guns Tank guns of South Korea Military equipment introduced in the 2000s ADD research and development projects