1. Focused ****l- The most commonly used ammunition allowance of modern tanks comprises two types of armor-piercing ****ls: HVAP and HEAT fragmentation or HVAP and high-explosive squash head (HESH). Once a HEAT-F or HESH ****l has been fired, the fragmentation and blast effects are secondary and collateral. It may well augment the armor-piercing effect to the detriment of other tank missions.
Explanations are offered in different original concepts of the tank as a weapons system. According to one such concept, the main tank mission is to fight enemy tanks presenting a major threat (to realize the "fight the equal" principle), while the tank defense against ground and air antitank weapons is considered the responsibility of a covering party, e.i., accompanying infantry combat vehicles and self-propelled air defense mounts.
When confronted by hit-and-run maneuver tank battle, especially on rugged, smoked and dust-laden terrain, the dominant factor is played by the readiness to fire instantly as soon as an enemy tank appears. To this end, the tank gun must be kept loaded, and any ****l of the ammunition load must provide high armor-piercing effect. The idea of ammunition allowance comprising two types of armor-piercing ****ls is based on this principle.
However, military experience disproves this concept. For example, the tank losses during the fourth Arab-Israel war in 1973 broke down as follows: over 50 percent destroyed by antitank guided missiles, 28 percent by aircraft, light antitank grenade launchers, tank-killing mines, and only 22 percent by tank fire.
Under another concept the tank constitutes a self-contained weapons system capable of accomplishing independently all combat missions, including self-defense against tank destroyers. This problem cannot be solved by using available standard impact-fuzed ****ls, as the fragmentation effect on single targets during flat trajectory fire by these ****ls indicates very poor coordination between the impact point f (x, y) and kill probability curve G (x, y).
2. Focused fragmentation ****l of Diehl company
The dispersion pattern, with a ratio of longer axes of approximately 50:1 at a distance of 2 km, is extended along the line of fire, while the bursting effect area is perpendicular to this line. As a result, the fire pattern and the bursting effect area only coincide over a very small section.
To find a way out, a multipurpose tank-gun ****l of versatile application boasting a killing pattern extended along the ****l path has been developed and patented by the Bauman State University Special Engineering Research Institute (Russian Lcns No. 2018779, M. cl. F42 V 13/48, published on August 30, 1994).
The ****l produces simultaneously two fragmentation patterns: axial (focused) pattern of submunitions and radial (circular) pattern of split fragments. The ****l comprises an explosive charge and a nose unit containing submunitions made from steel or heavy tungsten-based alloys in a form allowing for their dense stowage in the nose unit, for instance hexahedral prisms. Dense stowage retains the shape of submunitions during blast propulsion and consequently reduces the losses of explosive charge energy for submunition deformation. Owing to the base detonation of the explosive charge, the submunition unit is propelled by incident blast wave, thereby increasing the propulsion velocity. The velocity of the submunition unit ejection from the ****l body depends on the weight and other design parameters and ranges from 300 to 500 m/s, with the initial resultant velocity of the subminitions ranging from 1,100 to 1,300 m/s at a ****l velocity of 800 m/s. A light head cap provided with a point contact-sensing device and filled with polyurethane foam does not impede the submunition unit ejection.
3. Focused fragmentation mortar ****l of Diehl companyExplosion of a 125mm focused fragmentation ****l at a distance of 30 m from a target produces a killing circle 5 m in diameter. With the submunition unit and the submunition weighing 2.5 kg and 5 g, respectively, and a submunition total number of 500, the average density in the killing zone will be 25 pcs/m2 which is quite sufficient to reliably defeat any targets with a steel *****alent of up to 6 mm. A 15-20 g rise in the submunition weight will increase the steel *****alent of penetrated target up to 10 mm. It will be sufficient to defeat light armor targets. The effect of a dense submunition beam on the tank front armor will destroy all external vision devices and cause full blinding of the tank.
Time setting (time of flight to a set-forward point of burst) is introduced in the base or nose command receiver through a contact or noncontact line. To rule out errors, the ****l velocity is measured by the noncontact method and the resultant value is introduced into the computation of time setting. The latter is subsequently fed to the time fuze via a laser beam (or by any other noncontact method). The tank fire control system must incorporate a laser rangefinder, ****l velocity meter, ballistic computer and automatic time fuze setting device. Such systems have been developed and adopted for service.
This engagement method is an obvious asset related to the fire control system accuracy. When a time-fuze HE fragmentation ****l is exploded in the effective killing zone, the total error (root-mean-square deviation) of fire control must not exceed 0.001 s (this accuracy level is highly improbable in near future). For a focused ****l blasted at the point of prediction, a total error of up to 0.01 s will be acceptable.
4. Axially acted projectile of FFV company The time fuze is fitted with a percussion mechanism of three settings enabling the ****l to produce fragmentation-compression, fragmentation-blast and piercing-blast effect. Instantaneous fragmentation is effected by the nose contact device connected electrically to the base fuze. The command, determining the type of action, is fed through the nose or base command receiver.
Numerous computations and simulation of the ****l action corroborated its high ability to protect the tank against all types of tank destroyers, including the crews of antitank grenade launchers provided with individual armor protection means and positioned in trenches and ****ters, fixed and self-propelled antitank missile systems, antitank guns, antitank helicopters and attack aircraft. The use of focused fragmentation ****ls by active close-in tank defense system is promising. Replacing the 30F19 HE fragmentation projectile in the tank ammunition load with a multipurpose focused fragmentation ****l will give the tank an opportunity to survive in modern combat.
According to license publications, the development of focused fragmentation projectiles is underway in foreign states (Lcns 4524696 USA, Lcns 0101795 Europe, Lcns 4882296 USA, Lcns 3703773A1 FRG, Lcns 367869 Sweden and others). Examples can be found in the development of the tank focused fragmentation projectile and focused mortar ****l of the Diehl company and P-type axially acted fragmentation projectile of the Swedish FFV company.