The New 84mm AT4
ABOVE: The AT4 CS HE with Aimpoint FCS51. With regards to impact/airburst: The gunner chooses impact or airburst on the sight with 1 button. Photo: Saab Dynamics
New tools that give the soldier much greater flexibility to defeat the enemy
At DSEI 2015, September 15, 2015, London, new significant capabilities for shoulder-launched weapons systems were revealed by Defense and security company Saab. Displayed at their booth was the next-generation Carl-Gustaf M4 alongside new variants of the flexible, man-portable support weapon of the AT4 Family disposable shoulder-launched weapons:
• 84 mm AT4 CS ER (Confined Space Extended Range)–The disposable AT4 anti-armor weapons for short range, a weapon that gives the soldiers the ability to defeat combat vehicles with high penetration and devastating their interiors. It combines easy handling, low weight and high velocity with impressive firepower and high armor penetration.
• 84 mm AT4 CS HE (Confined Space High Explosive) – The ANTI-PERSONNEL enables soldiers to defeat enemy troops in complex environments. The weapon can be adjusted to operate in air burst or impact mode, providing the flexibility needed for a range of combat scenarios.
The product range also includes the 84 mm AT4 CS AST—The ANTI-STRUCTURE is a lightweight, recoilless, fully disposable multi-target weapon suited to close combat ranges. It provides the dismounted soldier with the capability to defeat the multitude of targets encountered in close combat urban operations.
The two new AT4 CS ER and AT4 CS HE weapons will deliver respectively extended range (ER) and improved high explosive (HE) effects. This enables the soldier to defeat enemy targets with much greater flexibility and in many more scenarios. They were developed especially for Europe and were launched into production by a December 2014 order from the French Ministry of Defence procurement branch, the DGA (Direction Générale de l’Armement). The enhanced AT4 was selected, after a competitive evaluation, to serve as the Roquette Nouvelle Generation (Roquette NG) next-generation shoulder-launched weapon system for the French armed forces.
Back to the Past
Drawing on technology from the proven Carl-Gustaf reusable weapon, the AT4 was developed as a disposable equivalent. The AT4 was designed in Sweden by Försvarets Fabriksverk (FFV) which had tested over 100 weapons by early 1982 with the help of the Swedish Army. The disposable AT4 is an 84 mm unguided, anti-armor weapon manufactured by Saab. In 1982, the AT4 was introduced into the US Army before the weapon was adopted by Sweden. The US Army tested six different weapons in 1983 and found that the FFV AT4 met all the requirements needed to replace its M72 LAW weapon. The US Army adopted AT4 as the lightweight multipurpose weapon M136 AT4 after altering the weapon’s launch tube bumpers, sights and slings. The Swedish Army also adopted the Americanized version. The M136 AT4 is the Army’s primary light anti-tank weapon. It is used primarily by Infantry Forces for engagement and defeat of light armor. The weapon’s design permits accurate delivery of an 84 mm High Explosive Anti-Armor warhead, with negligible recoil. It is a lightweight, self-contained, consisting of a free-flight, fin-stabilized, rocket-type cartridge packed in an expendable, one-piece, fiberglass-wrapped tube. The M136 AT4 is man-portable and is fired from the right shoulder only. The launcher is watertight for ease of transportation and storage. Unlike the M72-series LAW, the M136 AT4 launcher need not be extended before firing. Subsequent to the initial fielding of the weapon, a reusable night sight bracket was developed and fielded. Aiming at the target with the AT4 is accomplished through range-adjustable plastic sights, which can be covered up under the sliding covers. Though the M136 AT4 can be employed in limited visibility situations, the firer must be able to see and identify the target and estimate the range to it. It permits utilization of standard night vision equipment. With an adapter, the weapon can be used with an optical night sight. In November 2010, Saab received an order from the French Defense Forces for the light anti-tank weapon AT4 (confined space), a variant of AT4. PROJECT MANAGER CLOSE COMBAT SYSTEMS discontinued purchase of the AT4 in favor of its newest iteration, the AT4 Confined Space system.
M136A1 AT4 Confined Space (AT4-CS) is a man-portable, single-shot, disposable anti-armor shoulder launched munition that can be fired from a confined space,
significantly increasing the Soldier’s ability to engage in urban conflict.
It weighs 7.5 kg and has an effective range of 300 m. The self-contained weapon consists of a free flight, fin stabilized, rocket-type cartridge packed in an expendable, 1-piece, fiberglass-wrapped tube. Its recoilless design is superior to that of rocket-type weapons for confined space applications. Resistance to shock damage contributes to the AT4’s high reliability. In April 2011, Saab received a $17m order from unknown customer to deliver AT4-CS RS version during 2012. The RS in the designation AT4-CS RS stands for Reduced Sensibility. A Press release 15 September 2015 from Defense and security company Saab said that Saab has received an order from the US Army for the shoulder-launched AT4CS RS anti-armor weapon system. Deliveries will take place during 2016.
Today’s Versions of the AT4 Family
The AT4 family is a range of lightweight, man-portable, fully disposable weapons characterized by ease of use and handling.
This means they do not require expert gunners to operate the weapon effectively. All AT4 weapons are single shot and fully disposable. The shooter simply aims, fires and destroys the target and discards the empty tube. Furthermore, the AT4 family has proven itself to be a highly reliable, robust and durable weapon system that has been extensively proven in combat. Its key characteristics include high target effect and hit probability–creating a high target kill probability for each fired weapon.
The new members of the AT4 family along with night and confined space (CS) launch capabilities and the extended range required for mission success further expand the great versatility of the weapon. The AT4 ammunition is effective against combat vehicles, assaulting tanks, landing craft, helicopter, aircraft and armored vehicles. They can also be used for the protection of vital assets, fixed defense installations
and key supply points. The AT4 weapons are maintenance free.
The New Versions
What were on display in London were the three versions which Saab has developed for European customers.
The AT4 CS ER –Extended Range is a development of the current AT4 CS. In addition to the integrated Red-Dot sight the launcher has a bracket for mounting an advanced sight. The empty launcher with the Red-Dot sight is disposable. The advanced sight is for reutilization. Effective range is > 500 m. Using traditional light shoulder launched weapons requires the gunner to leave his concealment and protection for a street corner or a rooftop, to be able to engage the enemy. With confined space capability the soldier is able to use the full potential of tactical advantage that the urban environment or jungle condition offers. The dismounted soldier can now engage a mechanized enemy from the protection and concealment a building structure. The AT4 CS ER has achieved an extended range by having changed the launcher tube a little bit in order to get a higher V0. All versions have a Red-Dot Sight, that’s standard. In order to obtain the full utilization of the extended range, the launcher has a bracket for an advanced sight. An advanced sight helps to fire with the correct ballistics to increase the hit probability and increases the range to reach out to about 600 m. The warhead’s maximum penetration is > 400 mm. AT4 CS ER is the basic weapon that is purchased. And then there’s also an anti-structure variant, the AT4 CS AST designed for effect against targets like brick walls, concrete walls and light armored vehicles. The range is 20-400 m and it can be fired from Confined Space. The Red-dot sight is compatible with helmet mounted NVG. The warhead part looks something like the one that the 84 mm Carl-Gustaf M4 recoilless rifle has, but the AST has a slightly different main charge. The function principle is the same. A “breaking charge” makes a hole in the wall while the main charge goes through and detonates inside.
In addition with the CS AST, the shooter can choose MODE.
Normally one selects “LAST MODE,” and it works as mentioned above; that it makes a hole in the wall, and the main effect section enters and works behind the wall. Then there is “Breach MODE” by turning the selector and then it will have another effect that makes the main charge detonate into the wall. That creates a big hole in the wall.
The soldiers can then enter a building without using doors or windows because for example in urban environment there may be hidden mine traps or hidden improvised explosives in entrances. The latest variant is the AT4 CS HE. What’s new is that Saab has produced a disposable weapon with a high explosive grenade. The warhead has its effect with tungsten spheres and the weapon’s effective range is > 1000m. The launcher has an integrated Red-Dot sight and a bracket for an advanced sight. The new high explosive grenade is programmable and this weapon also has an interface for the communication between the grenade and the ‘Intelligent’ sight. The gunner chooses impact or airburst on the sight with 1 button. He ranges the target, if he wants the detonation behind, above or in front of the target he manually adds or withdraws range on the +/- button. He always sees the chosen range in the optics. As an example: Let us say the gunner wants to defeat a target hiding behind an APC or tank (or wall). He ranges the APC, adds a few meters then shoots the AT4 HE aiming just above the APC. The HE will then detonate above and behind the APC, spreading shrapnel over a bigger area than an impact detonation would. This means that targets in defilade that you normally cannot engage now can be neutralized. All except the intelligent sight are disposed of after firing. All sights are calibrated at the production factory so soldiers do not need to adjust it, but just mount it and make it ready for firing. The mode can be selected as impact or air burst mode. The tungsten fragmentation covers an area of ~400 m2.
Other AT4s in the family are:
• AT4 HEAT. Dismounted soldiers are exposed to many threats, among them infantry fighting vehicles. The easy to operate AT4 HEAT provides a powerful defense against such adversaries.
AT4 HEAT is a shoulder-launched anti-armor launch weapon system providing a very high hit-probability with a range of 40-400 m. It has an unique warhead design that offers a very high kill-probability and the armor penetration is 350 mm.
• AT4 CS RS with confined space capability and reduced sensitivity explosive has a unique bimetal warhead design that provides high kill probability with an armor penetration of > 350 mm. Effective range is 20-300 m.
• AT4 CS HP has a warhead for maximum penetration of 500 mm and an effective range from 20-300 m.
The Red-Dot Sight is an integrated part of the weapon, not a clip-on sight just for night firing capability. The big advantages with this integrated factory mounted and bore sighted sight is: only one sight for training and combat in all light conditions. The advanced sight, or some prefer to call it “Intelligent,” is the advanced Aimpoint FCS51.
It is a combination of a sight and fire control system for use with Multiple Weapon Platforms. The FCS51 system comprises an eye safe laser range finder, a ballistic computer, and a parallax free optical channel with unlimited eye relief. Terrain angle compensation is measured by an integrated inclinometer. The FCS51 automatically compensates for the ballistic drop of projectiles at measured distances, factoring in variables such as rotational (spin) drift, propellant temperature, and terrain angle. The design is small and rugged. The rear of the sight has an interface with push buttons for settings. FCS51 has compatibility with all generations of Night Vision Devices. Its power supply consists of quick change battery power packs which will last for 6 months operation for more than 200 combat sequences. FCS51 implies a dramatic increase in hit probability and reduces time used for engagement, which in turn raises the overall effectiveness of the weapon system considerably. In most cases, the operator only needs to push one button before pulling the trigger of the weapon. The FCS51 automatically compensates for the ballistic drop of projectiles at measured distances, factoring in variables such as rotational (spin) drift, propellant temperature and terrain angle. When the distance is measured, the ballistics are calculated and compensated immediately. The aiming Red-Dot reticle changes position in the optical channel electronically. If ammunition type is changed, the ballistic algorithm is entered and utilized automatically, so no new measuring of the distance is required.
New international small arms concepts require light multi-purpose weapon with effects against a multitude of different targets.
For combat outside built-up areas the requirements for weapons with a long combat range and with various warheads remains or is even increased. Combat in built-up areas requires weapon systems that are robust, light and easy to carry and that have good effect on various types of targets, including armored vehicles. More and more is the importance to have weapons that can be used in confined spaces. Besides the famous Carl-Gustaf weapon system, Saab has its AT4-CS family in caliber 84 mm which also has confined space (CS) capability. The soldier’s one-man low weight, heavy impact weapon AT4 family combines versatility, ease of use and high performance into a highly flexible and effective multi-purpose weapon system that can be employed in a wide range of scenarios and against a wide variety of targets. For future tactical operations there will be multitudes of different support weapons available. For infantry and dismounted soldiers, lightweight shoulder-launched disposable weapons will undoubtably be of great importance.