Russo-Ukrainian War: The ZSU-23-4M1 Shilka SPAAG

Source: front_ukrainian on X™

     In its heyday, the ZSU-23-4 Shilka (meaning “Awl”) was a much feared SPAAG (Self-Propelled Anti-Aircraft Gun) as it was far superior to all anti-aircraft guns then deployed by Western forces. The ZSU-23-4 proved its worth during the Yom Kippur War in 1973, devastating Israeli Air Force aircraft who were flying low to avoid 2K12 Kub (NATO reporting name SA-6 Gainful) SAMs (Surface-to-Air Missiles). The ZSU-23-4 was not just lethal to low flying aircraft but also against ground targets. Some NATO country military doctrines at the time stated when infantry units engaged Soviet or Warsaw Pact armored columns, if a ZSU-23-4 was present, it was to be targeted and destroyed first. This is because its four 23mm cannons could decimate infantry with ease. Eventually, the ZSU-23-4 was eclipsed by more modern SPAAGs and in Russian service, the 2K22 Tunguska was its successor. Nevertheless, despite entering service in 1962, the ZSU-23-4 remains in active service with 25 countries, including Ukraine. As such, some countries have upgraded the ZSU-23-4 to better compete on the modern battlefield. These countries include Belarus, India, Iran, the Netherlands, Russia, and Ukraine. The photograph shows a ZSU-23-4M1, one of sixteen, that were upgraded by donations made through the Come Back Alive Foundation. This particular vehicle is in service with the 13th. Operational Brigade “Khartia”, a unit within the National Guard of Ukraine. The name of the vehicle is “Alligator” (“АЛІГАТОР”) and the crew has shot down four Russian Geran-2 drones as shown by the kill markers on the hull side.

     Power for the 20-ton ZSU-23-4 comes from a V6R-1 6-cylinder, water-cooled diesel engine that develops 290 horsepower and this can push the ZSU-23-4 along roads to a maximum speed of 31 miles per hour and off-road, terrain depending, to a top speed of 19 miles per hour. 136 gallons of onboard fuel provide the ZSU-23-4 with a maximum road range of 280 miles but if moving off-road, the range drops to 186 miles.

     The ZSU-23-4 is built upon a GM-575 tracked chassis and the manufacturer in Russia was the Mytishchi Machine Building Plant. It has six road wheels per side and no track return rollers. The four man crew is protected by welded steel armor though it is not thick. The hull front and sides support 15mm thick armor while the turret has between 8mm to 9mm of armor protection. This makes the ZSU-23-4 vulnerable to most battlefield weapons. In fact, the 5.56mm M995 tungsten core AP (Armor Piercing) round can penetrate 12mm of armor at 100 meters so heavier calibers can threaten the ZSU-23-4 from much greater ranges. Other protective equipment include a overpressure NBC system and the ability to mount 81mm smoke grenade launchers. Communication equipment inside the ZSU-23-4 includes a digital R-123 system which has a maximum range of 31 miles. The driver is provided with a BMO-190 daylight periscope while the commander is provided with a TPKU-2 daylight periscope and a TKH-ITC infrared periscope.

     The sole armament of the ZSU-23-4 consists of the AZP-23 “Amur” weapon system which comprises four water-cooled 2A7 23mm autocannons. The turret provides 360 degrees of traverse while the stabilized mounting for the AZP-23 permits a maximum of 85 degrees of elevation and 4 degrees of depression. Each 2A7 autocannon has a maximum cyclic rate of fire between 850 to 1,000 rounds per minute which means with all four autocannons firing, the ZSU-23-4 can put 3,400 to 4,000 rounds per minute into the sky. In practice, 10 to 30 round bursts are fired at a time for a 400 round per minute sustained rate of fire. The reason for short bursts is because the ZSU-23-4 has a maximum of 2,000 rounds of ready ammunition (520 rounds for each top cannon and 480 rounds for each bottom cannon) and once expended, it takes 20 minutes to reload. Another reason for short bursts is to prevent barrel overheating. The effective direct fire range of the AZP-23 is 1.6 miles and a effective vertical firing range of 3.2 miles. Typical ammunition fired includes the BZT blunt steel core API (Armor Piercing Incendiary) round which can penetrate 15mm of rolled homogeneous armor at a 30 degree slope at 1,000 meters and the OFZT HE-T (High-Explosive Tracer) round. Often, the ammunition will be a mixture of AP and HE rounds to engage different target types. In addition to radar controlled automatic target engagement, the AZU-23 can be manually aimed and fired if the radar system fails or is jammed.

     The radar system in this upgraded ZSU-23-4M1 replaces the standard RPK-2 “Tobol” (NATO reporting name Gun Dish) fire control radar with a more modern set. While the specific performance parameters of the new radar have not been disclosed, a December 22, 2025 report on the website Zona Militar states that the effective radar range is “doubled” which would mean a 24 mile target detection range (the RPK-2 is 12 miles) and a tracking range of 22 miles (compared to 11 miles for the RPK-2). The ZSU-23-4's original fire control apparatus has been replaced with digital equivalents that reduces the engagement time from 12 to 18 seconds down to under 1 second. Also, the new radar permits simultaneous tracking of up to 20 targets.

Russo-Ukrainian War: The 35D6M Radar Complex

     A screen capture from an informational video produced and released by the Ukrainian Air Force's 138th. Radio-Technical Brigade “Dnieper Ukraine” shows one of the brigade's 35D6M radar stations. The contrast between the base green paint on the radar complex and the brown of the fall/winter terrain emphasizes that this is a information production and not a shot of the complex in actual active deployment. Had it been, the 35D6M would have been easily spotted by Russian reconnaissance UAVs and targeted for destruction. The 35D6M is a modernization of the Soviet 19Zh6 (NATO reporting name Tin Shield) medium-range, 3D air defense radar which entered service in the early 1980s. The modernization program was undertaken by the Iskra Research & Production Complex, a part of Ukroboronprom, with the first 35D6M being delivered in the spring of 2021.

     According to Ukroboronprom, the modernization program updated the antenna apparatus, saw the installation of improved system and operating software, and the fashioning of a cabin that includes a total rework of the radar operator's stations and the fitting of a HVAC system. The complete details of the modernization isn't specified in articles, likely for operational security. Iskra took 19Zh6 radar complexes and completely took them apart. After the complete disassembly, all components were inspected and those parts that were to be re-used were refurbished before being reassembled with the updated parts as outlined above. It was said that the modernization of a single 19Zh6 into a 35D6M was not a quick process. The result is, again according to Ukroboronprom, a complex that has increased operational range, improved target data and trajectory acquisition, reduced maintenance requirements, and the extension of the complex's service life. As the various articles leave out the exact performance capability of the 35D6M, what follows are the specifications of the 19Zh6 radar.

     As mentioned, the 19Zh6 is a medium-range, 3D radar. The 3D (3 dimensions) means the radar provides the usual range and azimuth coordinates but adds the elevation coordinates and with all three, target tracking is far more precise. The radar itself uses a frequency-controlled, phased array antenna and it operates in the E- and F-band frequencies (2,850 to 3,200 MHz). Four transmitters generate overlapping wave patterns which improves altitude calculations. Pulse power is 3.2 kW as an average but can run as high as 350 kW. The Russian Wikipedia mentions the 35D6M as having a target detection range of 29 miles at low altitude and 108 miles at medium or high altitudes. There was no source provided with which to verify the data. Speaking of low altitude, the 19Zh6 and the 35D6M are optimized for low altitude target detection as the radar is resistant to active and passive jamming but is also able to filter out strong ground reflection (more often called clutter) from terrain, buildings, and other stationary objects. Finally, the radar is able to work effectively in all weather conditions. The radar antenna spins either at 5-6 revolutions per minute (rpm) or 10 to 12 rpm. The complex features BITE (Build-In Test Equipment) which permits rapid fault detection. The exact crew size for the entire complex isn't known but is likely between 7 to 10 men which would include at most 5 radar operators/technicians, at least two tractor drivers, and the remainder being mechanics to maintain the equipment. From the halt, it takes a trained crew 1 hour to bring the radar into action.

     The full 35D6M complex includes a 6BP power plant which houses two DGM 4-60-T0230-TS/400 diesel generators along with a PSTS-100 converter. The power plant sits inside a KP10 box body which is set on a MAZ-5224V 2-axle trailer chassis. The unit provides the power to the radar and its associated systems. The radar system and the 6II cabin sit on a MAZ-938 series 2-axle semi-trailer which has a maximum load capacity of 13.5 tons. The radar array is mounted on a 40V6M tower mast. The vehicle hitched to the MAZ-938 is a KrAZ-255V tractor. Besides the KrAZ-255V, the KrAZ-260V can also be utilized as a tow vehicle for both the semi-trailer and the 6BP.

Russo-Ukrainian War: The Rheinmetall Oerlikon Skynex® SHORAD System

Source: inukraine.official on Instagram

     Germany, as part of its continued military support to Ukraine, has pledged four Rheinmetall Oerlikon Skynex® air defense systems. Of the four, one was delivered in January 2024 with the second in April 2024. The third and fourth systems have yet to be received. Skynex® is what is termed a SHORAD (Short-Range Air Defense) system and the Ukrainian military has deployed them as part of the air defense network that protects critical infrastructure. The first public appearance of Skynex® in Ukrainian service occurred when the Ukrainian Air Force released a video showing the system in action in September 2024 and the image here, a screen capture from a video, appeared in social media in July 2025. The Skynex® system is designed to be modular and a benefit to Ukraine, given the varied sensors made by different manufacturers deployed by the Ukrainian military, is that Skynex® is compatible with some of them.

     The Skynex® system, as offered by Rheinmetall, consists of four components. The first is the Oerlikon Skymaster® BMS (Battle Management System). Sometimes referred to as a C2 system (Command and Control), the BMS takes in data from radar/sensor systems, processes that data, and outputs a COP (Common Operational Picture) to commanders. From this information, situational awareness is provided, decisions can be quickly made, and coordination can be maintained between subordinate units. The Skymaster® BMS is specifically designed to manage both tactical and strategic air defense networks though it can be adapted for other roles based on requirements of the purchaser.

     The second piece of Skynex® is the Oerlikon X-TAR3D® tactical acquisition radar. The X-TAR3D, a phased-array pulse Doppler radar, is situated within a square metal container which is placed upon a solid surface, elevation/stabilization jacks on each corner of the container. The container houses all of the apparatus needed to operate the radar. The radar itself works in the X-band frequency range which is 8 to 12 gigahertz. This is a short wavelength but offers high target resolution along with the added benefit of needing a small antenna that makes concealment easier. The X-TAR3D is also a 3-dimensional radar, meaning it provides not only range and azimuth information but also elevation data. The X-TAR3D can track up to 16 targets simultaneously and it can identify aircraft, helicopters, cruise missiles, UAVs, and even unguided rockets and mortar bombs. Maximum range is 31 miles.

     The third component within the Skynex® system is the Oerlikon MSU (Multi-Sensor Unit). As the name suggests, the MSU is packed with various sensor suites and search radars. Like the radar, the MSU is within a metal container, approximately the size of a 10 foot standard shipping container. The roof of the container has two hatches which, upon being opened, the MSU is raised up and out. The suites consist of 3-dimension AESA radars (Active Electronically Scanned Array), panoramic EO (Electro-Optical) sensors (in a remote controlled turret atop the MSU), ECCM (Electronic Counter-Countermeasures), clutter mapping capability (which allows the radars to ignore stationary objects), and the ability to use either active or passive target tracking functions. The MSU is thus able to detect a host of threats in any weather conditions, day or night, in a 360 degree radius. Maximum detection range is 19 miles. The MSU fully interfaces with the Skymaster® BMS. The MSU can be upgraded with IFF (Identification Friend or Foe), additional ELINT sensors (Electronic Intelligence), and zenith radar. The latter is a specific type of radar that operates in the Ka-band (34.8 GHz) and is typically used to measure atmospheric conditions.

     The final piece of Skynex® is the Oerlikon Revolver Gun® Mk.3. Chambered for the 35x228mm round (which, as a note, is also used by the Flugabwehrkanonenpanzer Gepard that is in service with the Ukrainian military), the Revolver Gun Mk.3 can spit out 1,000 rounds per minute though the more regular rate is a long burst of 200 rounds per minute. The gun sits within a unmanned turret situated on a ground plate. The turret can rotate a full 360 degrees at a rate of 115 degrees per second and so this means the turret can revolve fully in 3.1 seconds. Gun elevation is a maximum of 85 degrees while the maximum depression is 10 degrees. Elevation speed is 57 degrees per second and so from 0 degrees, it can reach its maximum elevation in 1.5 seconds. Ready ammunition capacity is 252 rounds. The Revolver Gun can fire a wide array of 35mm ammunition to include Oerlikon's AHEAD KETF (Kinetic Energy Time Fuze) round. The “AHEAD” comes from the fact the round doesn't directly strike the target but instead, it creates a cone shaped cloud of 152 cylindrical, aerodynamic tungsten alloy submunitions (each with a weight of .12 of an ounce) ahead of the target. The fuze is set electronically as the round leaves the barrel. Other ammunition types include HEI (High-Explosive Incendiary), HEI-T (High-Explosive Incendiary Tracer), FAP (Frangible Armor Piercing), and TP-T (Target Practice Tracer). The typical range for the 35x228mm round is 3.4 miles. The weapon is also able to engage in C-RAM fire missions. Standing for Counter-Rocket, Artillery, and Mortar, this means the Revolver Cannon Mk.3 can engage incoming unguided rockets, artillery rounds, or mortar bombs.

     The Revolver Gun Mk.3, by itself, is a self-contained SHORAD. It has either a X-band or Ku-band tracking radar (19 mile range) along with a EO sensor suite consisting of a HD CMOS (Complementary Metal-Oxide-Semiconductor) TV camera, a cooled MWIR (Mid-Wave Infrared) IR camera, laser range finder, and a video tracking system. It can be fitted with an optional S-band or X-band ARES search radar. The Revolver Gun Mk.3 platform can detect, identify, track, and engage targets fully autonomously. Of course, the weapon is meant to be tied into the BMS as well as take advantage of the X-TAR3D and MSU components. In addition, the BMS can manage up to eight Revolver Gun Mk.3 systems.

Russo-Ukrainian War: The Zastava M55 20mm Automatic Cannon

Source: Ministry of Defense of Ukraine

     A soldier belonging to the 243rd. Territorial Defense Battalion, 241st. Territorial Defense Brigade sits in the gunner's seat of a Zastava M55 20mm automatic cannon. The photograph was taken in the winter of 2023. The M55 is a Yugoslavian (now Serbian) license built Hispano-Suiza HS.804 20mm L/70 anti-aircraft cannon mounted on a Hispano-Suiza HS.630-3 towed carriage. Originally built by the Crvena Zastava arms company (now Zastava Arms), the single-barrel M55 (some sources designate it the 20/1 mm M55) first entered service with the Yugoslav People's Army in 1955. Despite the age of the M55, it remains in production as it is robust and dependable. Slovenia provided Ukraine with 200 M55 systems, both single-barrel and triple-barrel (known in some sources as the 20/3 mm M55), in 2022.

     The M55 is chambered for the 20x110mm HS round and it has a gas operated, delayed blowback action. The M55, sans the carriage, has an empty weight of 94 pounds and with a full 60-round drum magazine, the weight increases to 151 pounds. The maximum rate of fire is between 600 to 700 rounds per minute with each round leaving the barrel at a muzzle velocity of 2,800 to 2,900 feet per second. With the muzzle brake, the recoil force is 881 pounds.

     The 20x110mm HS cartridge case was brass with more modern production ammunition using steel cases. The standard HEI (High-Explosive Incendiary) round has approximately 32 grams of propellant with between 10.75 to 11.4 grams of explosive. The effective range against aerial targets is just under 1 mile (.9 of a mile) while the maximum range of the round is 2.7 miles. Fuzes include delayed-action and impact types. The M55 shown here is not fitted with any sights but the mount for an optical sight can be seen above the magazine.

     The M55 can fire against ground targets if need be with an effective range of 1.2 miles. Today, the typical ammunition availability for the 20x110mm HS round (in addition to the HEI discussed above) includes HEI-T (High-Explosive Incendiary Tracer), HE-T (High-Explosive Tracer), and HE (High-Explosive). Armor-Piercing (AP) ammunition was made for the cannon but performance required the M55 to be at close range to be effective. The AP round could penetrate 15mm of hardened steel at a 40 degree slope at a range of 365 meters. A more effective APCR (Armor-Piercing Composite Rigid) round, using a tungsten core, was produced that allowed for around 38mm of armor penetration at 365 meters at a 30 degree slope.

     As the M55 is manually operated, the cannon is mainly in service with anti-UAV units as the slow speed of drones such as the HESA Shahed 136 (around 115 miles per hour) are more easily tracked and targeted by such weapons.

Russo-Ukrainian War: Supacat HMT 600 w/ ASRAAM

Source: Ministry of Defense of Ukraine

     In February 2024, a video appeared online showing this vehicle, a British Supacat manufactured 6x6 HMT 600 (High Mobility Transporter) which is fitted with a launch system for the British ASRAAM (Advanced Short Range Air-to-Air Missile; AIM-132 in U.S. service) short range missile. It was originally believed this was the British Gravehawk SAM system but more recent reports state the pictured “FrankenSAM” is not Gravehawk. The final Gravehawk system is fitted within a standard shipping container which is transported by a Leyland DAF 8x8 DROPS (Demountable Rack Offload and Pickup System) truck. It uses Soviet-era Vympel R-73 missiles that are utilized by Ukrainian Air Force fighters as short range AAMs (Air-to-Air Missiles). As there is a surplus of R-73 missiles (NATO reporting name AA-11 Archer) due to the fact air-to-air combat between Ukrainian and Russian jets is rare, the R-73 is seeing use as a SAM.

     However, the launcher on the Supacat HMT 600 is very similar to the one used on the Gravehawk, down to the shiny bolts that hold it together. In addition, the mast mounted sight is nearly identical to the one used on the Gravehawk. So, it is very possible that some of the equipment and apparatus seen here on the Supacat HMT 600 was incorporated into the final Gravehawk system.

     Returning to the ASRAAM, it entered service in 1998 and it uses a dual-burn, high-impulse solid fuel rocket motor that can accelerate the ASRAAM to speeds exceeding Mach 3 (2,300 miles per hour). The maximum range around 30 miles. For a warhead, the ASRAAM has a 22 pound HE-FRAG (High-Explosive Fragmentation) payload and it can be triggered by one of two means: proximity fuze or impact. The ASRAAM uses LOAL (Lock-On After Launch) which means it can be launched and the onboard inertial guidance system will guide the missile towards the target, making adjustments as necessary to ensure a hit. There looks to be a Chess Dynamics Hawkeye optical suite which provides targeting, tracking, and target identification for the operator. The suite can be used with the ASRAAM to bring it to bear on a target. Speaking of targets, the ASRAAM is primarily deployed against Russian drones, loitering munitions, and cruise missiles.

     As for the HMT 600, it is powered by a Cummins 6-cylinder diesel engine developing 180 horsepower and this provides for a top road speed of 75 miles per hour. The engine is paired to a Allison 5-speed automatic transmission. 53 gallons of fuel provide for a maximum cruise range of 435 miles. The cab is armored though to what level isn't stated in Supacat literature. It is also mine-resistant, in part due to the high wheelbase. Other features include ABS (Anti-lock Brake System), power steering, adjustable ride height, and four-wheel drive. As optional items, the HMT 600 can be fitted with runflat tires, self recovery winch, smoke grenade launchers, a RWS (Remote Weapons Station) mount, and IR lights.

Russo-Ukrainian War: The KS-19 100mm Anti-Aircraft Gun

Source: Reddit

     Another venerable artillery piece is shown here, the KS-19 100mm anti-aircraft gun. First accepted into service in 1948, the KS-19 was the long range companion to the AZP S-60 57mm anti-aircraft gun, the latter engaging targets at short- to medium ranges. In fact, both weapons shared the same SON-9 (NATO reporting name Fire Can) fire director radar while in Soviet service. The advent of SAMs (Surface-to Air Missiles) saw the KS-19 phased out with no attempt to keep it viable with modern target detection and fire control systems as has been done with the AZP S-60. Thus, the Soviets sold off most of the approximately 10,500 KS-19 to friendly client states and the gun still sees service to this day with a little over a dozen countries. The KS-19 first appeared in the Russo-Ukrainian War soon after the start of the conflict when the Russians captured a number of Ukrainian KS-19 guns that had been in storage in the city of Balakliia, Kharkiv Oblast. Lacking ammunition, the Russians set up some of the KS-19s as decoys. The Ukrainians retook the city on September 10, 2022 during the Kharkiv counteroffensive and recovered the KS-19 guns. In the spring of 2023, the KS-19 next appeared in Ukrainian service as ammunition had been acquired (or located from stocks). Since then, the KS-19 has shown up in social media from time to time with some of the guns mounted on heavy trucks. The KS-19 is deployed as a quick firing artillery gun, delivering indirect fire (or even direct fire) against enemy targets.

     The towed KS-19 weighs in at 10 tons and so once it is set up in a firing position, it cannot be manhandled around. In Soviet service, the KS-19 was usually towed by a fully tracked AT-S or AT-T prime mover but any truck with a compatible towing ability can be used as well. Maximum tow speed on roads is 25 miles per hour. It takes time to both set up the KS-19 as well as prepare it for moving which makes it vulnerable to counter-battery fire. This is one reason gun trucks using the KS-19 have been put into service to provide more rapid mobility. The gun uses a semi-automatic, horizontal sliding wedge breech block which means that after firing, the empty shell case is automatically ejected from the breech. The KS-19 has a power rammer and a well trained crew (a full crew is 15 men though as few as 7 men can man the KS-19) can manage a maximum of 15 rounds in a single minute. A more sustained rate of fire is 9 rounds per minute while a hour long bombardment is between 1 to 2 rounds per minute. This allows for barrel cooling. The KS-19's gun mount permits a maximum elevation of 85 degrees and no more than 3 degrees of depression. The mount sits on a turntable which permits 360 degrees of traverse. While moving the gun is manual, the traverse and elevation controls are powered. 

     The photograph here shows a KS-19 in a dug-in position and it has a rather worn looking appearance. The two seats are for the gunners who control the gun's position. The dual hand cranks are for the traverse while the single hand crank is for elevating and depressing the gun barrel. The squarish box-shaped components contain dials which contain the azimuth and elevation indicators and for the one at the rear, the fuze setting apparatus (which would be used if the KS-19 was engaged in anti-aircraft fire). The telescopic sight for direct fire is visible along with the corresponding round aperture in the gun shield. Right behind it is the panoramic periscope sight used for indirect fire. The top half of the gun shield can be lowered down with the shield thick enough to only provide protection against light small arms calibers and shell splinters.

     When firing the UOF-412 HE (High-Explosive) round, the KS-19 can lob the shell and its 3 pound TNT warhead out to a maximum of 12 miles. The shell uses a V-429 series fuze and a NDT3 propelling charge. If forced to combat enemy armor, the KS-19 can fire the BR-412B AP-T (Armor-Piercing Tracer) round that has a maximum range of 2.5 miles but an effective range of .6 of a mile where the BR-412B can penetrate up to 185mm of armor. The BR-412B uses A-IX-2 explosive and also utilizes the NDT3 propelling charge.

     It is not known exactly how many KS-19 are in active service with Ukrainian forces but as of March 17, 2025, none have been reported as lost by the Oryx website.