On the 20th in the afternoon at the prototype fabrication room inside SNT Dynamics A Campus in Changwon, South Gyeongsang. Four outriggers (launch supports) on the rear of the small tactical vehicle (KLTV) came down, and a 120 mm mortar turned its body 45 degrees to aim at the target.
When the ammunition carrier attached to the barrel rammed the shell into the tube, the gunner pressed a button. This was a demonstration of the firing sequence of the small tactical vehicle–mounted 120 mm mortar (wheeled mortar) that SNT Dynamics is developing. The process took only about 40 seconds. There was no actual firing, and the shell was a dummy round.
At the site that day, SNT Dynamics researchers were carrying out "optimization" work on the wheeled mortar. Simply put, the wheeled mortar is a mortar mounted on the back of a vehicle (tactical vehicle). The Marine Corps has been operating this mortar on a trial basis since May.
The researchers supplied power to the vehicle through a separate battery to check the status of the electronic devices. They are identifying and applying improvements based on feedback from Marine Corps field use. Senior researcher Ko Jeong-min at the technology research center said, "We finished building the prototype, but we are conducting test runs and other trials to create the best possible condition before mass production."
◇SNT develops new mortar based on barrel manufacturing technology
Inside A Campus that day, thin, silver cylindrical steel rods stood out. After processes such as cutting rifling (spiral grooves inside each gun and gun barrel), these rods become barrels used in the K6 heavy machine gun.
The technology for cutting rifling is a core technology of SNT Dynamics. Based on rifling manufacturing know-how accumulated by supplying the K6 heavy machine gun and the 20 mm Vulcan gun to the military, SNT developed the 120 mm mortar system, and, beyond the "Bigyeok" mounted on the K200 armored vehicle, went on to build a wheeled mortar through in-house development.
Development of the wheeled mortar began to boost fire support for amphibious operations. The 4.2-inch (107 mm) mortars previously used by the military had a short range. Bigyeok was also an armored vehicle, so it lacked mobility and was too heavy for air transport.
To enable a wider range of operations, SNT Dynamics invested tens of billions of won to independently develop the first mortar based on a tactical vehicle. It won the rapid pilot program in 2023 and has now completed a prototype of the wheeled mortar.
The key to the wheeled mortar is recoil mitigation technology. The force applied when a shell is fired from a mortar is 400 tons. SNT Dynamics' independently developed recoil mechanism (a device that returns the barrel to position after it recoils) reduces this impact first. It attenuates the recoil by slowing the speed at which the barrel returns to position. Thanks to this, the firing shock is said to drop to the 50-ton level.
Kim Jong-do, head of the technology research center (executive director), who oversaw the mortar's development, said, "An armored vehicle can absorb a 50-ton shock, but a tactical vehicle could not," and added, "We succeeded in additionally absorbing the shock by designing a system that diverts it into the ground through a hydraulic damper and outriggers."
The outriggers lift the vehicle in proportion to the pressure applied to the suspension to reduce the shock a second time, and the damper filters it once more. As a result, the firing shock applied to the vehicle after a shot has been reduced to about 10 tons.
Weight reduction was also a high-difficulty task. The tactical vehicle weighs 3.5 tons, and the mortar system alone weighs 1.4 tons. Adding various fire-control devices, crew members, and ammunition pushed the total over 7 tons. If it exceeds 7 tons, it cannot be transported by helicopter.
SNT Dynamics integrated the sights (targeting device) into one to reduce the crew from five to three, and cut the mortar's rotation arc from the previous 360 degrees to 220 degrees. A full 360-degree rotation requires parts weighing about 100 kg. The wheeled mortar examined that day had fewer steel plates on the rear of the body than the model displayed at ADEX in Oct. last year.
◇Interest from countries around the world... The ultimate target is the U.S. military
SNT Dynamics makes the transmissions for the K9 self-propelled howitzer and the K2 tank, which are leading export items for Korea's defense industry. That day, numerous transmission housings (frames that hold components) were on display at the defense assembly plant, and on-site workers were busy assembling transmissions. The entire assembly plant looked devoted to transmissions.
This is also why the wheeled mortar is important to SNT Dynamics. For the first time since its founding, the company has made a finished product rather than parts, and it could become a new source of revenue.
Market conditions are favorable. That is because the need for weapons systems that can be operated quickly and deliver precision strikes alongside drones has grown. A reconnaissance drone finds a target and a nearby platform strikes it. Thanks to this, the Army is also said to be reviewing commercialization.
Director Jo Jae-bong of SNT Dynamics said, "Drones are cited as a key weapon, but they cannot cover all firepower on the battlefield," and added, "The concept of operations that precisely concentrates fire on targets scouted by drones can also be applied to the wheeled mortar." The wheeled mortar fires 10 rounds per minute and has a maximum range of about 13 km.
SNT Dynamics is accelerating exports. It says it has received continuous inquiries since two years ago from the Middle East, West Asia, and Southeast Asian countries, which are riding the global trend of increased defense spending. Overseas customers want the mortar mounted on other 4x4 vehicles, such as Toyota pickup trucks.
Kim Jong-do said, "Since we have already reduced firing shock to the level of about 400 tons, the mortar can be sufficiently used even when mounted on commercial trucks," and explained, "We are also developing models to mount on various vehicles, including medium tactical vehicles."
To operate it unmanned, the system needs to switch from a semi-automatic in which the gunner places ammunition to automatic loading, and the mortar system must be developed in a turret configuration. A turret means a steel structure built so that only the barrel is exposed externally to protect the crew, and it is for automatic loading and ammunition supply, which are central to unmanned operation.
Kim added, "In addition, to achieve unmanned operation, we must switch from muzzle loading, in which a shell is inserted into the mouth of the barrel, to 'breech loading,' like a self-propelled howitzer, in which loading is done from the rear of the barrel," and said, "We are continuing research for an unmanned system."
SNT Dynamics' ultimate goal is the U.S. military market. SNT Dynamics currently manufactures and exports defense parts not produced in the United States. Rather than immediately trying with finished goods, it plans to proceed step by step, starting with the U.S. military's maintenance, repair, and overhaul (MRO) market based on the technologies it has secured.
Jo Jae-bong said, "In advanced markets such as the United States and Germany, the industrial ecosystem, including partner firms, has largely collapsed," and added, "We aim to seize this opening to expand our footprint."