Aircraft / Aviation Vehicles & Artillery Small Arms Warships & Submarines Military Ranks Military Pay Chart (2024) Special Forces
Land Systems / Battlefield

K9 Thunder

155mm Self-Propelled Gun (SPG) / Field Howitzer [ 1999 ]

It is reported that the South Korean K9 Thunder SPG can land three successive shells in a single target area within 15 seconds of firing the first.

Authored By: Staff Writer | Last Edited: 09/09/2022 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.

The K9 Thunder is a relatively new addition to the forces of the South Korea Army and is of indigenous design and production. Having spent decades utilizing American-based weaponry, the nation has increasingly looked inwards to field a more modern army to counter any aggression from the North. A complete nation for a time in its history, Korea was divided after Japanese invasion in World War 2 between the communist North (backed by the Soviet Union) and the democratic South (backed by the United States. A formal invasion of the South by the North (with Soviet and Chinese blessing) brought about the Korean War (1950-1953) that ultimately resulted in a loose armistice with the conclusion of war never formerly declared. As such, the North and South have seen tensions rise and fall throughout the decades since the division, leading to a regional arms race backed by major world powers. Despite the constant threat of nuclear weapons across the Korean Peninsula today, it remains that artillery will play a grand role in any large-scale ground operations between the North and South armies and the K9 Thunder fits the bill - able to lob 155mm high-explosive, nuclear, anti-infantry projectiles some 40 kilometers away. The K9 is in the same class of vehicles as the highly modernized American M109 "Paladin", the British AS-90 and German PzH-2000 155mm self-propelled gun platforms and utilizes the latest in South Korean engineering and digital technology unmatched by any product of the North.

Design of the K9 by Samsung Techwin began in 1989 and prototypes were unveiled in 1994. A period of evaluation and delivery of pre-production vehicles spanned into 1998, ultimately leading to serial production and formal introduction of the system as the "Thunder" into the Republic of Korea Army in 1999. Since then, the type has seen approximately 532 examples delivered for service to both the Army and Marine Corps branches of service and has already seen combat action when K9 units delivered salvos against the North in November of 2010 in a return fire action.

The K9 is crewed by five specialists made up of the driver, vehicle commander, gunner and a pair of loaders managing the 155mm projectiles. The driver maintains a forward-left hull seating, apart from the crew, whilst the rest of the crew takes their places in the fully enclosed turret superstructure. The turret sports slightly sloped side panels and a flat roof. Various modern internal systems give the gunnery crew of the K9 a distinct battlefield edge in sustainable rate-of-fire and placement of rounds over any known system available to the North Korean Army. While the K9 is not necessarily designed to fire "on the move", her systems are designed as such that her weaponry can be brought to bear in short order (setup time is reported to require just one minute of preparation) and the whole vehicle can then be displaced to a new firing location as required - making for a harder target to locate and engage for the enemy. This type of mobility is a much sought-after quality on today's modern battlefield, giving the K9 a distinct "smart" edge in open warfare.

However, the true key to the success of the K9 system is its use of what is known as a "Time on Target" digital fire control system. The fire control system manages the firing action of the main gun. This computerized arrangement allows the gunnery crew the ability to land three successive 155mm shells in one area, having fired all three rounds in the span of just 15 seconds. The integrated computer calculates the second and third shell's trajectory based on the first that was launched and automatically adjusts the firing of these two successive projectiles to allow all three shells to arrive "on target" at the same time - more of less ensuring a neutralized target or target area.

Outwardly, the K9 shares a design arrangement not unlike the American M109 it replaces what with a rear-set, slab-sided turret emplacement and boxy hull. The turret sports the 155mm main gun attached to an internal mount and necessary recoil system. Traversal of the main gun within its mount is +70 to -2.5 with 360-degree rotation possible thanks to the rotating powered turret structure. Various side- and roof-mounted hatches make for relatively easy entry/exit by the crew and for the purposes of ammunition resupply. Communications antenna are noted at each rear corner of the turret roof as is a stowage rack along the rear facing. "Pioneer tools", that is, items such as sledgehammers, shovels and axes can be mounted to support arms on the outside of the turret, these tools useful for digging the crew and vehicle in for the long haul. Steel-based armor protection is reported at 19mm in maximum thickness and both an NBC (Nuclear, Biological, Chemical) and nightvision system are standard in the K9's design.©MilitaryFactory.com
Primary armament is a long-barreled 155mm L52 series /52 caliber main gun that is cleared to fire a plethora of standardized projectile types. Rocket-assisted munitions can also be utilized to increase the gun's maximum reach is need be, keeping her far from the dangers of the frontlines. The barrel sports a noticeable fume extractor midway across its length and a unique multi-baffled muzzle brake is used to help retard the inherently violent recoil of launching a 155mm explosive projectile. The main barrel can be locked into place over the forward hull with a folding support arm when the K9 is in transport (the length of the gun barrel necessitates that it be stowed in this fashion). South Korean engineers have also developed an indigenous high-explosive round known under the designation of "K307" that is the standardized projectile of the K9 and the loading process is further handled by an automatic function that lessens crew workload with only the charges needing management by the loaders as required. The main gun is supplemented by a defensive-minded 12.7mm Daewoo K6 heavy machine gun to help combat low-flying aircraft and is managed by the commander via a provided cupola. The 12.7mm heavy machine gun is supplied with 500 rounds of ammunition.

While some 48 x 155mm projectiles are stowed about the interior of the K9, the Thunder is resupplied in action by the automated K10 ammunition carrier which utilizes the same hull and track design of the K9 (sans the powered turret) making it an economically and logistically "friendly" measure produced alongside the K9. The K10 is identifiable by its protruding ammunition arm and fixed superstructure but more or less maintains the same appearance and layout as the base K9. A powered tray on the K10 "feeds" fresh 155mm projectiles in through the rear of the K9 turret structure.

The K9 is powered by a German-based MTU brand MT 881 Ka-500 series 8-cylinder, water-cooled diesel engine delivering up to 1,000 horsepower at 2,750rpm. This allows the Thunder a top speed of 67 kilometers per hour as well as an operational range of approximately 480 kilometers. The engine is mounted to the right of the driver's seating placement in the forward hull and mated to an S&T Dynamics Company X1100-5A3 series transmission system. The K9 features hydropneumatic suspension across all of its road wheels allowing for excellent cross-country mobility - a requirement considering the rugged nature of the Korean countryside. There are six rubber-tired road wheels to a track side with the drive sprocket mounted to the front of the track system, the track idler at the rear and three track return rollers between and above the first, second and third wheel pairings. The K9 can ford water sources up to 1.5 meters deep.

Beyond the South Korean Army, Turkey has become a recent recipient of the K9 with license-production of the Thunder as the T-155 "Firtina" (translating to "Storm"). Some 300 or so of these Turkish variants are expected to be fielded within time. Following Turkey's lead is Egypt which remains a potential customer of the K9 as well, with an agreement between it and South Korea having been formed. Egypt has also fielded the American M109. The Australian Army is reportedly considering the South Korean K9 in an effort to modernize its current stable of artillery systems.

July 2016 - The Finnish Army has selected the K9 Thunder as its new SPG platform.

February 2017 - The Finnish Army has announced that up to 48 ex-South Korean Army K9 vehicles will be acquired to modernize its land forces (succeeding an aging stock of field howitzers). These are designated K9FIN "Moukari" ("Sledge-Hammer").

November 2018 - The Indian Army has formally introduced the localized K9 VAJRA-T ("Lightning") self-propelled gun systems from South Korea. One-hundred units will eventually make up the fleet. Final deliveries will occur before the end of 2020.©MilitaryFactory.com
Note: The above text is EXCLUSIVE to the site www.MilitaryFactory.com. It is the product of many hours of research and work made possible with the help of contributors, veterans, insiders, and topic specialists. If you happen upon this text anywhere else on the internet or in print, please let us know at MilitaryFactory AT gmail DOT com so that we may take appropriate action against the offender / offending site and continue to protect this original work.

February 2017 - The Finnish Army has announced its intention to purchase 48 refurbished K9 systems from South Korea with first-deliveries set to begin sometime in 2017.

December 2017 - It was confirmed by Hanwha that Norway has ordered twenty-four K9 Thunder SPA vehicles with an option for twenty-four more. The deal includes six K10 ammunition resupply vehicles.

June 2018 - Estonia has agreed to the purchase of 12 K9 SPA vehicles from South Korea.

January 2019 - Deliveries of Norwegian Army K9 Thunder vehicles are set to begin some time in 2019 with the final unit delivered during 2021.

October 2019 - Estonia has contracted for an addition six K9 SPA vehicles from South Korea.


Samsung Techwin - South Korea
Estonia; Finland; India; Norway; Poland (as "AJS Krab"); South Korea; Turkey (as "T-155")
Operators National flag of Estonia National flag of Finland National flag of India National flag of Norway National flag of Poland National flag of South Korea National flag of Turkey
Service Year
South Korea
National Origin

Project Status

Support allied forces through direct / in-direct fire, assault forward positions, and / or breach fortified areas of the battlefield.

39.4 ft
(12 meters)
11.2 ft
(3.4 meters)
9.0 ft
(2.73 meters)
113,979 lb
(51,700 kg)
57.0 tons

1 x MTU MT 881 Ka-500 8-cylinder, liquid-cooled diesel engine developing 1,000 horsepower driving conventional track-and-wheel arrangement.
Drive System
42 mph
(67 kph)
Road Speed
298 miles
(480 km)
Road Range

1 x 155mm L52 main gun in turret.
1 x 12.7mm Daewoo K6 anti-aircraft heavy machine gun on turret roof (OPTIONAL).
48 x 155mm projectiles (K307 HE).
500 x 12.7mm ammunition.

XK9 - Prototype Designation.
K9 "Thunder" - Base Production Series Designation.
K9A1 (K9 PIP) - Upgraded Fire Control System (FCS); InfraRed periscope at driver's position; rear-view camera for improved situational awareness; Auxiliary Power Unit (APU) integration.
K9 VAJRA-T ("Lightning") - Indian Army export model based in the K9 Thunder development.
K9FIN "Moukari" ("Sledge-Hammer") - Finnish Army export model.
K10 - Ammunition Resupply Vehicle.
T-155 "Firtina" - Turkish Export Variant based on the K9.
AHS Krab - Local Polish Army development mating the turret of the British AS90 system with the chassis, hull and running gear of the K9.

Military lapel ribbon for the American Civil War
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of the Bulge
Military lapel ribbon for the Battle of Kursk
Military lapel ribbon for the Cold War
Military lapel ribbon for the Falklands War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Ukranian-Russian War
Military lapel ribbon for the Vietnam War
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental military vehicles


1 / 2
Image of the K9 Thunder
Image from Hanwha Defense marketing materials.
2 / 2
Image of the K9 Thunder
Image copyright www.MilitaryFactory.com; No Reproduction Permitted.

Disclaimer | Privacy Policy | Cookies

2024 Military Pay Chart Military Ranks DoD Dictionary Conversion Calculators Military Alphabet Code Military Map Symbols

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com. No A.I. was used in the generation of this content; site is 100% curated by humans.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org (World Directory of Modern Military Aircraft), WDMMW.org (World Directory of Modern Military Warships), SR71blackbird.org, detailing the history of the world's most iconic spyplane, and MilitaryRibbons.info, cataloguing military medals and ribbons. Special Interest: RailRoad Junction, the locomotive encyclopedia.

©2023 www.MilitaryFactory.com • All Rights Reserved • Content ©2003-2023 (20yrs)