[Military Story] K-Defense Self-Propelled Guns Firing Salutes... The Secret is 'Customized Production'

World's No.1 Self-Propelled Howitzer
Inside Hanwha Aerospace Changwon Plant
2nd Facility Among 55 Buildings Spanning 61,312 Pyeong
Producing 8 Mobile Systems Including K-9 Howitzer and Cheonmu
70-80% of Ground Weapon Systems Welded by Robots
Automated Production of About 400 Tracked Vehicles Annually
Cheonmu Can Be Produced at One Unit per Month
Functions Customized to Importing Countries' Requirements

During the Korean War in 1950, North Korea attacked South Korea with T-34 tanks. Our military was fearful. They called them the "steel monsters." This was natural for the South Korean army, which had no tanks at the time. North Korea mass-produced tanks independently up to the T-62 Cheonmaho in the 1970s. Our military became desperate. It was only in the 1980s that the Korean-type next-generation tank plan was established, leading to the birth of the first domestically produced tank, the K-1. Former President Chun Doo-hwan named it the "88 Tank" to commemorate the Olympic Games.

Tank technology rapidly advanced. The K-9 self-propelled howitzer became the pride of "K-Defense." It holds the number one market share in the global self-propelled howitzer market. At the "World Defense Show 2024 (WDS, Saudi Defense Exhibition)" held in Riyadh, Saudi Arabia until the 8th of this month, the K9 self-propelled howitzer equipped with a domestically produced engine was unveiled for the first time. Also attracting attention were the Redback armored vehicle, unmanned reconnaissance vehicles equipped with Cheonggeom, the Tigon, and the Cheonmu rocket with a range of 290 km. Leading this trend is Hanwha Aerospace. We visited Hanwha Aerospace’s Changwon plant, which stands out in exporting "K-Defense" to the extent that it expands its production line every year.

Ground weapon systems lined up in a row at the ground test site. From the left in the photo: Cheonmu launcher, Cheonmu ammunition carrier, 30mm wheeled anti-aircraft gun 'Cheonho', self-propelled anti-aircraft gun K30 Biho complex, infantry fighting vehicle (IFV) K-21, 120mm self-propelled mortar 'Bigeok', infantry fighting vehicle (IFV) Redback (Photo by Hanwha Aerospace)

Hanwha Aerospace’s Changwon plant covers an area of 200,000㎡ (61,312 pyeong). Among the 55 buildings, we headed to the 2nd business unit responsible for ground operations. Inside the production plant, there are seven spans referring to factory lines. Each span assembles different ground weapon systems. On site, eight types of mobile systems including the K-9 self-propelled howitzer, Cheonmu, and Redback were being produced. Production of vehicles derived from main ground weapon systems is also possible. For example, a Cheonmu ammunition transport vehicle is made as a derivative of Cheonmu. Span 1 is divided left and right into robot welding and manual welding sections.

Robots handle 70-80% of the welding work for ground weapon systems. Humans weld in places where robot arms cannot reach. The silver vehicle bodies after welding looked like large assembly parts. Company officials identified them as 120mm self-propelled mortars, K200s, etc., just by appearance. To the reporter’s eyes, they all looked the same. Moving to Span 2, a rail-guided mobile unmanned vehicle (RGV) carrying cargo approached. The RGV can carry up to 15 tons, easily transporting the upper part of a tank.

Robots perform 70-80% of ground weapon welding

Choi Jae-wan, head of production, said, "Thanks to automation, we can produce about 400 tracked vehicles annually," adding, "For the Cheonmu exported to Poland, we can produce one unit per month."

At Span 6, the Cheonmu operated by our military caught the eye. Cheonmu, composed of the Chinese characters for sky (天) and luxuriant (茂), means "to cover the sky densely with multiple rocket launchers." It was developed to replace our military’s "Guryong" (K136) multiple rocket launcher. Depending on the target, it can operate various types of ammunition such as 130mm podded cluster munitions, 230mm unguided rockets, and 239mm guided rockets, and can devastate an area equivalent to 12 soccer fields in 30 seconds.

Our military is performing overhaul maintenance on the infantry fighting vehicle (IFV) K-21, which has been put into service. (Photo by Hanwha Aerospace)

The Cheonmu in production had a different color from the one used by our military. This was to meet the importing country’s requirements. Its functions also differed. Fuel cooling and air conditioning performance were greatly enhanced. Protection could also be strengthened like a Mine-Resistant Ambush Protected (MRAP) vehicle upon request. This was possible because Hanwha Aerospace produces the main vehicle in-house. The eight vehicle wheels were taller than an adult’s waist. They were special tires capable of running at speeds of 45 km/h or more for over 45 km even when hit by bullets.

In-house produced vehicles are customized to regional characteristics

Each wheel was equipped with an independent device. When driving on soft ground, the air pressure automatically lowers to increase ground contact, and when driving on paved roads, the air pressure increases to improve driving performance. Each axle supporting two wheels had separate power, so there was no problem moving even if a mine was triggered. The crew compartment structure was also visible. The glass was 3 to 4 times thicker than that of regular vehicles. The protection level was 2, capable of defending against most rifle attacks. According to company officials, this increased crew survivability.

We moved to a 1.6 km long ground test track and boarded the "Cheonmu Homar-K (HOMAR-K)" export model for Poland. The Homar-K mounts Hanwha Aerospace’s Cheonmu module and guided missiles on a launcher vehicle supplied by JELCZ, a Polish state-owned defense company under the PGZ Group. The Homar-K is equipped with guided missiles with a range of 80 km and long-range guided missiles with a range of 290 km.

120mm self-propelled mortar 'Bigeok' being assembled on the production line. (Photo by Hanwha Aerospace)

The driver’s cabin was wider than expected, about 3 pyeong in size, and had a roof hatch that could be opened and closed. In combat situations, the hatch can be opened to fire. Starting the engine, it roared and sped along the test track at 50 km/h. Cornering was smooth.

Kang Hoon-gu, head of technology, said, "The domestically produced Cheonmu feels heavier when driving compared to similar general vehicles due to its weight, but it does not fall behind in ride comfort," adding, "The driving method is not different from general vehicles, so drivers can adapt easily."

After finishing the drive, the "heroes of K-Defense" gathered in one place. Infantry Fighting Vehicle (IFV) Redback, 120mm self-propelled mortar "Bigeok," IFV K-21, self-propelled anti-aircraft gun K30 Biho complex, 30mm wheeled anti-aircraft gun "Cheonho," and Cheonmu were lined up waiting for driving tests.