At the 2023 Annual Meeting of the Association of the United States Army held not long ago, Rheinmetall Ammunition of the United States exhibited a "Rough Sawtooth" unmanned air defense tank jointly developed with Textron Systems, which attracted attention. It is reported that the tank will be used for air defense operations, and its main task is to provide solutions for anti-drone operations.
With the M5 unmanned combat vehicle as the chassis, it is flexible and maneuverable
The "Rough Sawtooth" unmanned air defense tank consists of two parts: the Ripsaw M5 unmanned combat vehicle chassis and the Sky Ranger 30mm air defense turret weapon system.
The Ripsaw M5 unmanned combat vehicle is the latest unmanned combat vehicle developed by Textron Systems. The vehicle is divided into three types: heavy, medium and light. Currently, only the data of medium and light are known. Among them, the medium-sized vehicle has a combat weight of 10.5 tons, a length of 5.9 meters, a width of 2.7 meters, a height of 1.5 meters, a load of 3.6 tons, and a speed of 64 kilometers per hour; the light vehicle has a combat weight of 7.5 tons, a length of 4.7 meters, a width of 2.4 meters, a height of 1.5 meters, a load of 1.4 tons, and a speed of 72 kilometers per hour. At present, the medium-sized vehicle has been handed over to the US Army for relevant tests. The "coarse sawtooth" unmanned air defense tank uses the chassis of the medium-sized vehicle.
The chassis of the "coarse sawtooth" unmanned air defense tank adopts a torsion bar-balanced suspension, with 6 small-diameter road wheels and 4 track rollers on each side, and is equipped with a silent, high-life rubber-metal hybrid track. The power part consists of a 1,000-horsepower diesel engine and an Allison 9-speed automatic transmission, which can operate on various terrains, including deserts, snow, hills or uneven ground. The "Coarse Sawtooth" unmanned air defense tank is fast, flexible, has strong terrain passing ability, and is not very noisy during operation. It can maneuver quietly. In addition, its body is low and not easy to be discovered, and it has strong concealment ability.
As a military equipment, the "Coarse Sawtooth" unmanned air defense tank has a complete tank appearance and armor protection. The body adopts a basic passive armor design of 35-40 mm and the turret adopts a 25-30 mm design, which is enough to resist direct attacks from rifles or machine guns with a caliber of less than 12.7 mm. After adding some reactive armor or active defense systems, it also has a certain immunity to common anti-armor firepower such as RPG.
It is worth mentioning that the three types of Ripsaw M5 unmanned combat vehicles all use common components and common drive systems. By replacing the small chassis of the light version, the combat vehicle can be transported by helicopter. It is the first truly retractable vehicle of its kind. In addition, the chassis of Ripsaw M5 can also complete the switching and installation of different remote weapon systems within a few hours, with a payload of up to 2,700 kg and flexible mobility. The "Rough Sawtooth" unmanned air defense tank also has such capabilities.
Using the Sky Ranger 30 air defense turret, aiming at air defense operations
In terms of weapon systems, Ripsaw The M5 unmanned combat vehicle is equipped with an MCT-30 turret designed by Kongsberg, Norway. The turret has a 360-degree firing range and a rotation rate of 60 degrees per second. It is equipped with a dual-channel 75-round MK44I 30mm automatic cannon, an M240 7.62mm coaxial machine gun, and can even install Javelin anti-tank missiles and guided rockets. The MK44 Bushmaster cannon weighs about 154.6 kg, is about 3.4 meters long, and has 16 rifling grooves in the barrel. The gun is driven by a 24-volt motor and can fire 250 rounds per minute. It can choose single-shot, 5-round burst and full-automatic modes, with an effective range of 2,000 meters and a maximum range of 3,000 meters.
According to Textron Systems, the Ripsaw M5 can also be equipped with other weapon systems, such as the M2 12.7mm machine gun, the M240 7.62mm machine gun or the MK19 40 automatic grenade launchers, and even the "Javelin" anti-tank missile with a range of 2,000 meters are also optional.
The "Coarse Sawtooth" unmanned air defense tank that appeared at the 2023 Annual Meeting of the Association of the U.S. Army uses the Sky Ranger 30 air defense turret, with a seat diameter of 1,414 mm, and has STANAG4569 standard level 2 armor protection, which can be upgraded to level 4 protection. It is equipped with a 30mm KSE revolving gun. Testing began at the end of 2021 and full-scale test firing began in mid-2022.
The gun was developed based on the 30mm Oerlikon KCA airborne gun (Saab 37 gun) developed in the 1970s. It uses 30x173mm caliber ammunition, 252 rounds of ammunition, and an actual rate of fire of up to 1,000-1,200 rounds per minute. It can also fire AHEAD programmable ammunition. AHEAD ammunition is at a distance of When the gun barrel is opened, data about the best time to explode in the air is received. When they detonate, a cone-shaped group of tungsten alloy sub-projectiles is produced, increasing the probability of hitting, especially on smaller targets such as drones and cruise missiles. The gun has an elevation angle of -10 to +85 degrees, a strike range of 3,000 meters, and a rate of fire of 16 rounds per second. The turret is also equipped with a ROSY multi-spectral smoke grenade launcher system, equipped with two 9-mounted smoke grenade launchers, which is convenient for covering its own withdrawal from the combat area when necessary.
There is a reserved space on the left side of the turret for installing air defense missile launchers, which can be installed with two to four various types of infrared or laser-guided short-range air defense missiles, including the US Stinger, MBDA’s Mistral missiles, and the UAE EDGE Group SkyKnightC-RAM missile system. The turret can also be equipped with a coaxial 7.62mm machine gun, mainly for local self-defense. Together with the 30mm main gun, the machine gun can be more widely used to attack ground targets.
The Sky Ranger-30, which is positioned as an unmanned weapon system, still has luxurious built-in sensors. The core is an S-band radar array. There are 5 independent phased array antennas around the turret to achieve 360-degree full coverage. The detection range of small targets of drone type can reach 20 kilometers. It can also be equipped with Oerlikon X-TAR3D X-band detection radar.
As a supplement and backup to the radar, the turret comes with a passive fast infrared search and tracking (FIRST) aiming system, which includes a thermal imaging M WIR camera with continuous zoom and a field of view of 1.3° to 23°; it also includes a CCD TV camera with continuous zoom and a field of view of 0.75° to 37°, and two laser rangefinders that can detect targets covertly at 6 kilometers. This is a valuable alternative to the system’s radar, especially when detecting and tracking more concealed threats, or when threats with strong electronic warfare capabilities. FIRST can also help quickly detect and identify threats, including those that may suddenly appear, especially smaller threats such as drones.
The turret can integrate the Skymaster fire control system internally, which can use artificial intelligence to distinguish targets and predict target behavior. The turret can also be equipped with a passive positioning antenna that detects drone radio control signals and a jammer that can reliably interfere with such signals and prevent drones from completing their missions, as well as a laser air defense system with advanced performance.
It is no exaggeration to say that the "Coarse Sawtooth" unmanned air defense tank using the Sky Ranger 30 air defense turret has unparalleled power in air defense combat capabilities, especially against drones.
Unmanned tank, high level of intelligence
As an unmanned combat vehicle, the "Coarse Sawtooth" unmanned air defense tank has a high level of intelligent informationization.
The "Coarse Sawtooth" unmanned air defense tank is equipped with panoramic cameras all around to provide an all-round view. At the same time, the vehicle is also equipped with a TaC FLIR 280-HD optoelectronic system. The system weighs 25 kilograms and is equipped with a 982 mm focal length lens. It has high-definition imaging, multi-field observation field of view, separate screen, screen display, medium-wave infrared thermal imager, short-wave infrared imager, can penetrate mist, smoke, haze, etc., and has laser measurement and illumination functions. The system uses artificial intelligence for target detection, can distinguish between animals and humans, and can strike enemy targets.
According to FLIR Systems, its artificial intelligence enhancement of situational awareness is mainly supported by the ATR algorithm, emphasizing the development of target recognition capabilities of multi-source information fusion. It is essentially a nonlinear dynamic system that simulates the human thinking system. By imitating the behavior of biological neural network systems, a large number of artificial neural unit nodes are constructed, and two or more sensor information that applies different imaging principles and works in different working environments is fused to make the image data more reliable, readable, and understandable.
In addition, the "rough sawtooth" unmanned air defense tank has a strong level of autonomous mission capability decision-making. At present, the autonomous mission capability is confidential, but the U.S. Department of Defense, in a directive document numbered DoD3009.09 issued in 2012, divides weapons with autonomous capabilities into three categories: autonomous weapon systems, semi-autonomous weapon systems, and autonomous weapon systems with human supervision. Among them, autonomous weapon systems refer to systems that can autonomously select and attack targets without the intervention of human operators once they are activated. Semi-autonomous weapon systems refer to systems that, once activated, only attack specific targets or target groups that have been selected in advance by human operators. Autonomous weapon systems with human supervision are designed so that human operators can supervise and control the weapon system when it occurs. At the Association of the United States Army, Textron Systems called the "Rough Sawtooth" unmanned air defense tank a semi-autonomous mission system with actual combat grade, which enables people to make a relatively basic judgment on its autonomous mission capability level based on the D0D3009.09 document.
Widely used and powerful multi-task capability
The "rough sawtooth" unmanned air defense tank is positioned as an air defense tank. Its main purpose is air defense operations. It can effectively deal with a series of air threats, including drones, cruise missiles, helicopters and low-altitude fixed-wing aircraft. The unmanned tank can rely on waypoint navigation to perform "guided follow-up movement" and "off-road movement" to perform convoy protection, perimeter defense, surveillance, rescue, border patrol and other tasks in deserts, snow, hills or rugged terrain.
It is worth mentioning that when dealing with large-capacity saturation attacks, cannon-based air defense systems have certain advantages over missile-based air defense systems, because the former can continuously strike multiple incoming targets as long as there is available ammunition. A press release from Raine Metal asserts: "Skyranger 30 can hold its ground and resist swarms of drone attacks."
But the system is an improvement on the Ripsaw M5 unmanned combat vehicle, which has strong expandability and multi-task type. Its weapon system can be quickly replaced and adjusted accordingly according to the combat environment and combat objectives to carry out different tasks.
In addition, the Ripsaw M5 unmanned combat vehicle has a hatch that can be opened downwards under the front of the body, and a small unmanned vehicle can be placed inside. This small unmanned vehicle model is the FLIRSUGV single-soldier robot. With the manipulator and battery installed, the robot weighs 13.6 kg and can be carried by one person in a backpack. It can be used for reconnaissance, bomb disposal, climbing stairs, lifting 10 kg objects, and can rotate 360 degrees continuously. It can obtain target images through four color cameras, greatly expanding the scope of application of the vehicle.
The rear of the unmanned combat vehicle can also carry a drone. The R80D "Skyraider" four-axis drone is selected. The drone is 0.45 meters high, 1.35 meters long, weighs 5 kg, has a maximum load of 3.5 kg, and a maximum air speed of 50 kilometers per hour. It can carry a 2 kg payload and stay in the air for up to 50 minutes, which can help the unmanned vehicle to scout the target ahead.
At the same time, minesweepers and minesweepers rollers can be installed under the front of the unmanned combat vehicle to perform tasks such as minesweeping and mine detection. When the "coarse sawtooth" unmanned air defense tank is responsible for air defense operations, it can also carry similar unmanned vehicles and unmanned aircraft to expand the diversity of tasks to cope with more complex combat environments.
Conclusion
In several regional conflicts in recent years, the influx of low-altitude targets such as drones has highlighted the fragility of ground air defense systems. Against this background, the United States and other Western countries have vigorously developed integrated air defense and anti-missile systems. From the current battlefield, artillery-based short-range air defense systems have more advantages. They are not only flexible and maneuverable, but can also be deployed on a large scale to continuously strike incoming targets, which is especially suitable for anti-drone operations. At present, artillery-based short-range air defense systems have become an important weapon in regional conflicts.
Regional conflicts in recent years have also shown that modern short-range air defense systems are facing diverse threats and require a large amount of short-range air defense firepower to provide protection. For this reason, it is not surprising that short-range air defense has become the theme of the 2023 Association of the Army Annual Meeting.
Several other short-range air defense systems were also exhibited at the 2023 Association of the Army Annual Meeting, such as the TRX tracked unmanned vehicle of General Dynamics Land Systems, equipped with 30mm artillery and "Stinger" missiles. There is also a ground-based air defense system with a remote-controlled turret equipped with a "smart sight", a small radar, etc., and a rifle. These displays reflect the US Army’s attention to the construction of short-range air defense capabilities, and are also in line with the US Army’s development strategy of empowering combat platforms through intelligent technology. The "Next Generation Combat Vehicle" project has been one of the US Army’s modernization priorities in the past six years, and robotics technology is also considered the most promising area in the Army’s armored vehicle product portfolio, which may change the way the US Army fights.
