K2 Tank to Be Fitted with a Domestic Heart Starting This Year [Yang Nakgyu's Defence Club]

Inside SNT Dynamics' Changwon Plant

The powerpack is the power source of the Army's main battle tank, the K2. It is a core system that combines the engine and the transmission, and is called the "heart of the tank." Until now, the heart of the K2 tank has been German-made. Development of a domestically produced powerpack began in 2005 with an investment of 96.4 billion won (48.8 billion won for the engine and 47.6 billion won for the transmission). The process was not smooth. As the development of the powerpack was delayed, the K2 tank development program was also pushed back. In the end, the military installed a German powerpack for the first batch of mass-produced K2 tanks, and for the second and third batches, it configured the powerpack with a domestic engine and a German transmission. Starting from the fourth batch of K2 tank mass production this year, a fully domestic heart will be installed. This comes 20 years after the start of powerpack development. The domestic heart is now also aiming for exports. To see this domestic heart, we visited SNT Dynamics in Changwon, Gyeongsangnam-do.

The powerpack, fitted with a 2-ton HD Hyundai Infracore engine and a 2.5-ton transmission produced by SNT Dynamics, must complete 19 tests. Photo by SNT Dynamics

SNT Dynamics is located inside the Changwon National Industrial Complex. Established in 1974 under the direction of former President Park Chung-hee, the Changwon National Industrial Complex is home to leading K-defense companies. From the entrance to the complex, signs for companies such as Hanwha Aerospace and Hyundai Rotem immediately came into view. These companies, now in the midst of a defense renaissance, were bustling with activity. At the main gate of SNT Dynamics, a line of trucks loaded with various parts continued without a break. The inside of the plant was also busy. In the assembly building, powerpack assembly was in full swing for the Altay tank, the Turkish version of the domestically produced K2 tank. It was the second powerpack unit for export. The domestic powerpack, consisting of an HD Construction Equipment (formerly HD Hyundai Infracore) engine and an SNT Dynamics transmission, has been mounted first on Turkish tanks rather than on K2 tanks in Korea.

Domestic powerpack to be installed from the fourth batch of K2 tank production

On one side stood an HD Hyundai Infracore engine weighing 2 tons. A 2.5-ton transmission produced by SNT Dynamics had to be mounted on it. Overhead, a crane capable of lifting 7 tons moved with a loud clatter. Assembly takes four hours. However, completion of assembly does not mean the powerpack is immediately finished. It must complete 19 tests, including temperature and output, under the same environmental conditions as in the operating country. In the case of the powerpack installed on the K9 self-propelled howitzer, it has to pass 37 tests.

A company representative said, "We have continued to improve the performance of the transmission for about seven years since domestic localization was halted," adding, "We have also succeeded in localizing key components of the automatic transmission, such as the transmission control unit (TCU), the hydrostatic steering unit (HSU), the transmission, the torque converter, and the brakes."

There were many difficulties in localization. To install the domestic powerpack on the fourth batch of K2 tanks, the transmission had to undergo a durability test. The results were dismal. A defect occurred after 306 hours, forcing the test to end before meeting the 320-hour durability requirement under defense specifications. The countermeasure proposed by SNT Dynamics was quality assurance. The company offered to provide five transmissions free of charge for maintenance/field support equipment (M/F) so that faulty powerpacks could be replaced immediately, to operate a maintenance support center staffed with specialists, to extend the warranty period by one to two years, and to provide free lifetime warranty for defective parts. The military agreed, keeping defense exports in mind. Every time K2 tanks equipped with German transmissions were exported, approval from the German government was required. There have also been criticisms that the high price and maintenance cost of the German transmission have had a negative impact on the price competitiveness of the K2 tank.

Spin-off variants accelerating alongside K2 tank powerpack development

Moving over to the test building, testing was in full swing on the powerpack installed on the K200 armored vehicle. The number 200 reflects the intention, at the time of development testing, to identify 200 defects and thereby create an armored vehicle with perfect performance. The produced transmission was being tested after being connected to an engine. The test items numbered 20, including oil leakage and coolant flow rate. When we went up to the second-floor test room, the monitors showed test progress over roughly two hours. One monitor displayed information about the product, such as product number, tester, and serial number, while another monitor showed engine output, gear shift information, and output (rpm) at a glance. From the second floor, the powerpack emitted an unceasing growl. It sounded as if its heart were about to burst.

A company official said, "With the application of a domestic transmission, the K2 tank powerpack has now been fully localized," adding, "We expect this to contribute to smooth follow-on logistics support and to the revitalization of exports going forward." He continued, "Recently, the price of the German transmission has risen by 20%, but the price of the domestic transmission has remained unchanged, so in the global market the transmission is emerging as a steady-selling product."

The K6 heavy machine gun was developed by the U.S. military for anti-tank use, but after World War II it has been mounted on vehicles and used as an anti-aircraft weapon or as a weapon to suppress enemy positions. Photo provided by SNT Dynamics

Across the way in the firearms factory, around 200 K6 heavy machine guns were waiting to be delivered to the military. The K6 heavy machine gun is the Army's main heavy machine gun. The K6 heavy machine gun was developed by the U.S. military for anti-tank use, but after World War II it has been mounted on vehicles and used as an anti-aircraft weapon or as a weapon to suppress enemy strongpoints. At a glance, it looked like a black steel bar, but as we followed the production line and watched the parts being assembled one by one, the form of a heavy machine gun gradually emerged.

Factory lines kept busy producing all types of gun barrels

A 30 mm automatic cannon also caught the eye. The barrel alone appeared to be a full 4 meters long. The 30 mm automatic cannon is combined with the portable surface-to-air missile Shingung and is called Biho Complex. Biho Complex plays a central role in the Army's low-altitude air defense operations. It protects troops from threats in the sky. The performance of the existing Biho self-propelled anti-aircraft gun has been brought up to the latest standard. Its long-range engagement capability has been enhanced, as has its ability to respond to various low-altitude aerial threats. Thanks to these performance upgrades, it is reliably fulfilling its role as the air-defense vanguard of mechanized units.