One of the ways to increase the likelihood of hitting a ground or air target is the use of the so-called. projectiles with programmable detonation. Such ammunition is detonated at a given point of the trajectory - the closest to the target and send the maximum possible number of submunitions to it. One of the first developments in this class was the AHEAD family of projectiles developed by the Swiss company Oerlikon Contraves.
Promising solutions
Oerlikon-Contraves has been developing artillery systems for various purposes for a long time. In recent decades, new requirements for guns have appeared, and the Swiss company has responded to them by developing promising projects.
Back in the nineties, work began on the topic of programmable detonation ammunition. In the next decade, new products went to landfills and exhibitions. The ammunition family received the designation AHEAD (Advanced Hit Efficiency And Destruction). To date, such products have managed to enter service in a number of countries.
The AHEAD project proposed increasing the effectiveness of firing through the use of a whole artillery complex. It included a projectile itself with special capabilities, a modified weapon with the necessary devices and fire control devices. Subsequently, the FCS and the equipment for the guns were adapted to be mounted on various artillery systems, incl. different calibers.
This modular approach has provided the AHEAD complex with well-known advantages. An artillery system of this kind can be built on the basis of different guns of all compatible calibers and used on different carriers. AHEAD shells have already been successfully deployed on a mass of land systems, incl. on combat vehicles, as well as on ships.
Cannon devices
To use AHEAD ammunition, the weapon must be supplemented with several special devices. The most notable of these is the muzzle programmer. It is a muzzle brake, supplemented by a large cylindrical block with electronic equipment. The device is mounted directly on the muzzle of the barrel; the cable is connected to the OMS.
Inside the sturdy casing, in its back and middle parts, there are two induction coils needed to measure the initial velocity of the projectile. A larger coil of the programmer is located in front of them. These devices are used consistently and solve different problems.
At the moment of firing, the projectile passes sequentially through two coils of the velocity meter. The LMS determines the speed of the projectile, makes corrections to the data for firing and issues the necessary signal to the programmer coil. That enters data into a special projectile fuse.
Programmable projectiles
The AHEAD ammunition family is built on the basis of common ideas and some unified components. By connecting the latter with the necessary devices and products, you can create an artillery shot of the required appearance. Thanks to this, three types of rounds for 35 mm cannons have already been developed. It is also possible to create similar products in caliber 30 and 40 mm.
AHEAD shells of all types have a similar architecture. The conical fairing is screwed onto a cylindrical body that can accommodate combat equipment. A programmable fuse is placed in the tail socket of the body. The entire product assembly is placed in the barrel of the sleeve. The design and dimensions of the hull elements, as well as the combat load, depend on the caliber and type of shot. All modifications use a unified fuse.
The fuse housing contains a receiving coil and a special energy source that is triggered by a shock when fired. Next to them is a programmable temporary device that receives data from the programmer and determines the duration of the flight. After a predetermined time, this device activates an electric igniter and detonates the projectile charge. The AHEAD fuse is triggered only at a given time - there is no contact mode.
For the safety of gunners, the AHEAD product has two stages of protection. The first is done mechanically: before the start of movement along the barrel, the fuse contacts are open, and it remains inoperative. The electronic fuse does not allow setting the flight time less than 64 ms, which corresponds to a range of 60-70 m. If the data entry fails, a self-liquidator is triggered 8 seconds after the shot.
An interesting feature of AHEAD is the minimum required combat equipment. All projectiles of this type have a split body containing ready-made striking elements. Due to this, it was possible to reduce to a minimum the bursting charge, which ensures the spread of the GGE.
Three ammunition
The ability to detonate at a given point on the trajectory gives the projectiles well-known advantages. They can be used to more effectively engage ground or surface targets. It also increases the effectiveness of firing at air targets. For use on different artillery systems for various purposes, three types of 35x228 mm rounds with shells of the AHEAD family were initially created.
The first example of the family is designated PMD062. It has dimensions at the level of "conventional" ammunition of the same caliber and weighs 750 g. The central part of the hull has split walls. When the fuse is triggered, it opens into six "petals", providing the output of the GGE. The projectile contains 152 cylindrical GGE, stacked in 8 longitudinal columns of 19 pieces each. The total mass of the elements is 500 g. The opening of the case and the release of the GGE are carried out due to the charge of an explosive with a mass of only 0.9 g.
The PMD330 projectile has a similar design, but it uses a different set of GGE. Its central compartment contains 407 striking elements - 11 columns of 37 units each. The mass of the GGE has been reduced to 1.24 kg.
The course to reduce GGE continued in the PMD375 project. This projectile is equipped with 860 GGE with a mass of 0, 64 g and has the same detonation controls and a charge for ejection.
The normal muzzle velocity for AHEAD projectiles is 1050 m / s. The muzzle device and the LMS automatically measure the real value of this parameter and make corrections to the entered data. After the fuse is triggered, the GGE scatter in the front conical sector up to 15 ° wide. A projectile body with a sharp fairing can also cause some damage to the target.
The heaviest GGE of the PMD062 projectile can effectively engage lightly armored and unprotected equipment, aircraft and aircraft weapons. Lightweight GGE from PMD330 are designed to deal with manpower and unprotected equipment. The PMD375 projectile is designed to engage small air targets, incl. UAV.
Application features
AHEAD projectiles are proposed to be used in different situations and against different targets. In all cases, the defeat is provided by a cloud of high-velocity GGE with a high penetrating effect. The ability to select the point of detonation gives the operator of the artillery system special opportunities.
The easiest way to use AHEAD is to shoot with detonation at a certain distance in front of the target. In this case, the target falls into the GGE expansion cone and receives maximum damage. Detonation of several projectiles at one point allows you to increase the impact or the likelihood of damage. This method of application is suitable for the destruction of ground and air targets.
A shooting technique called "String of pearls" is proposed. In this case, several shots are fired with the installation of fuses at different ranges. The shells are detonated almost simultaneously and form a kind of "thread". This can be used when it is impossible to measure the exact range to the target, to defeat a column on the track or trenches when firing from the flank.
If necessary, AHEAD projectiles can be used not only as fragmentation, but also as kinetic. The design of the ammunition allows you to break through brick and concrete walls, as well as metal ones, incl. armor barriers. For such a use of the projectile, it is enough not to program the fuse.
Wide use
The AHEAD family of projectiles was designed for 35 mm Oerlikon cannons and their derivatives. Together with new opportunities, this fact had a positive impact on the commercial prospects of development. New types of shells entered service with several states. They are used with air defense artillery, as well as in the armament of armored combat vehicles and ships.
New ammunition was developed on the basis of 35 mm AHEAD projectiles. First of all, unified shells appeared in caliber 30 and 40 mm. Some of them have already found application in real armored vehicles projects. It is also proposed to integrate a programmable fuse into the design of a 40-mm round for an automatic grenade launcher.
The Oerlikon Contraves AHEAD product line was one of the first of its kind, which allowed them to gain a foothold in the market. Even in the presence of foreign competitors, such ammunition retains its position and is not yet ready to concede to anyone. Moreover, the development company is doing everything possible to expand the range of rounds produced according to the wishes of various customers. It is likely that in the near future the basic 35-mm AHEAD products will become the basis for new types of artillery rounds.
