Over the course of a relatively short history of armored vehicles (BTTs) of the ground forces, which is about a hundred years old, the nature of the conduct of hostilities has repeatedly changed. These changes were of a cardinal nature - from "positional" to "mobile" war and, further, to local conflicts and counterterrorist operations. It is the nature of the proposed military operations that is decisive in the formation of requirements for military equipment. Accordingly, the ranking of the main properties of BTT changed. The classic combination "firepower - defense - mobility" has been repeatedly updated, supplemented with new components. At the present time, the point of view has been established, according to which the priority is given to security.
A significant expansion of the range and capabilities of anti-armored vehicles (BTT) made its survivability the most important condition for the fulfillment of a combat mission. Ensuring the survivability and (in a narrower sense) protection of the BTT is based on an integrated approach. There cannot be a universal means of protection against all possible modern threats, therefore, various protection systems are installed on BTT facilities, mutually complementing each other. To date, dozens of structures, systems and complexes for protective purposes have been created, ranging from traditional armor to active protection systems. In these conditions, the formation of the optimal composition of complex protection is one of the most important tasks, the solution of which largely determines the perfection of the developed machine.
The solution to the problem of integrating protection means is based on the analysis of potential threats in the expected conditions of use. And here it is necessary to return to the fact that the nature of hostilities and, consequently, the "representative outfit of anti-tank weapons"
compared, say, with World War II. Currently, the most dangerous for BTT are two opposite (both in terms of the technological level and methods of application) groups of means - precision weapons (WTO), on the one hand, and melee weapons and mines, on the other. If the use of the WTO is typical for highly developed countries and, as a rule, leads to fairly quick results in the destruction of enemy armored vehicles groups, then the widest use of mines, improvised explosive devices (SBU) and hand-held anti-tank grenade launchers by various armed formations is of a long-term nature. The experience of the US military operations in Iraq and Afghanistan is very indicative in this sense. Considering such local conflicts to be the most typical for modern conditions, it should be admitted that it is the mines and melee weapons that are most dangerous for the BTT.
The level of threat posed by mines and improvised explosive devices is well illustrated by the generalized data on the losses of equipment of the US Army in various armed conflicts (Table 1).
Analysis of the dynamics of losses allows us to state unequivocally that the mine action component of the complex protection of armored vehicles is especially relevant today. Providing mine protection has become one of the main problems facing the developers of modern military vehicles.
To determine the ways to ensure protection, first of all, it is necessary to assess the characteristics of the most probable threats - the type and power of the mines and explosive devices used. Currently, a large number of effective anti-tank mines have been created, differing, among other things, in the principle of action. They can be equipped with push-action fuses and multichannel sensors - magnetometric, seismic, acoustic, etc. The warhead can be either the simplest high-explosive, or with striking elements of the "shock core" type, which have a high armor-piercing ability.
The specifics of the military conflicts under consideration do not imply that the enemy has "high-tech" mines. Experience shows that in most cases mines, and more often the SBU, of high-explosive action with radio-controlled or contact fuses are used. An example of an improvised explosive device with a simple push-type fuse is shown in Fig. 1.
Table 1
Recently, in Iraq and Afghanistan, there have been cases of the use of improvised explosive devices with striking elements of the "shock core" type. The emergence of such devices is a response to the increase in the anti-mine protection of BTT. Although, for obvious reasons, it is impossible to make a high-quality and highly efficient cumulative assembly with “improvised means”, nevertheless, the armor-piercing ability of such SBUs is up to 40 mm of steel. This is quite enough to reliably defeat lightly armored vehicles.
The power of the mines and the SBU used depends to a large extent on the availability of certain explosives (explosives), as well as on the possibilities for their laying. As a rule, IEDs are made on the basis of industrial explosives, which, at the same power, have a much greater weight and volume than "combat" explosives. Difficulties in the hidden laying of such bulky IEDs limit their power. Data on the frequency of use of mines and IEDs with various TNT equivalents, obtained as a result of generalizing the experience of US military operations in recent years, are given in Table. 2.
table 2
Analysis of the data presented shows that more than half of the explosive devices used in our time have TNT equivalents of 6-8 kg. It is this range that should be recognized as the most probable and, therefore, the most dangerous.
From the point of view of the nature of the defeat, there are types of blasting under the bottom of the car and under the wheel (caterpillar). Typical examples of lesions in these cases are shown in Fig. 2. In case of explosions under the bottom, it is highly probable that the integrity (break) of the hull and the destruction of the crew both due to dynamic loads exceeding the maximum permissible ones and due to the impact of a shock wave and fragmentation flow are very likely. Under wheel explosions, as a rule, the vehicle's mobility is lost, but the main factor affecting the crew is only dynamic loads.
Fig 1. Improvised explosive device with push-type fuse
Approaches to providing mine protection of BTT are primarily determined by the requirements for the protection of the crew and only secondarily by the requirements for maintaining the vehicle's operability.
Maintaining the operability of the internal equipment and, as a consequence, technical combat capability, can be ensured by reducing the shock loads on this equipment and its attachment points. Most
critical in this regard are components and assemblies fixed to the bottom of the machine or within the maximum possible dynamic deflection of the bottom during blasting. The number of attachment points for equipment to the bottom should be minimized as much as possible, and these nodes themselves should have energy-absorbing elements that reduce dynamic loads. In each case, the design of the attachment points is original. At the same time, from the point of view of the bottom design, in order to ensure the operability of the equipment, it is necessary to reduce the dynamic deflection (increase the rigidity) and ensure the maximum possible reduction of the dynamic loads transmitted to the attachment points of the internal equipment.
Crew maintenance can be achieved if a number of conditions are met.
The first condition is to minimize the dynamic loads transmitted during detonation to the attachment points of the crew or landing party seats. If the seats are attached directly to the bottom of the car, almost all the energy imparted to this section of the bottom will be transferred to their attachment points, therefore
extremely efficient energy-absorbing seat assemblies are required. It is important that providing protection at high charging power becomes questionable.
When the seats are fastened to the sides or roof of the hull, where the zone of local "explosive" deformations does not extend, only that part of the dynamic loads that are distributed to the car body as a whole are transferred to the attachment points. Considering the significant mass of combat vehicles, as well as the presence of factors such as suspension elasticity and partial energy absorption due to local deformation of the structure, accelerations transmitted to the sides and roof of the hull will be relatively small.
The second condition for maintaining the crew's working capacity is (as in the case of internal equipment) the exclusion of contact with the bottom at the maximum dynamic deflection. This can be achieved purely constructively - by obtaining the necessary clearance between the bottom and the floor of the habitable compartment. Increasing the rigidity of the bottom leads to a decrease in this required clearance. Thus, the performance of the crew is ensured by special shock-absorbing seats fixed in places far from the zones of possible application of explosive loads, as well as by eliminating the contact of the crew with the bottom at maximum dynamic deflection.
An example of the integrated implementation of these approaches to mine protection is the relatively recently emerging class of MRAP armored vehicles (Mine Resistant Ambush Protected), which have increased resistance to explosive devices and small arms fire (Fig. 3) …
Figure 2. The nature of the defeat of armored vehicles when undermining under the bottom and under the wheel
We must pay tribute to the highest efficiency shown by the United States, with which the development and delivery of large quantities of such machines to Iraq and Afghanistan were organized. A fairly large number of companies were entrusted with this task - Force Protection, BAE Systems, Armor Holdings, Oshkosh Trucks / Ceradyne, Navistar International, etc. This predetermined a significant reduction in the MRAR fleet, but at the same time allowed them to be delivered in the required quantities in a short time.
The common features of the approach to ensuring mine protection on the cars of these companies are the rational V-shaped shape of the lower part of the hull, increased strength of the bottom due to the use of thick steel armor plates and the mandatory use of special energy-absorbing seats. Protection is provided only for the habitable module. Everything that is "outside", including the engine compartment, either has no protection at all, or is poorly protected. This feature allows it to withstand undermining
sufficiently powerful IEDs due to the easy destruction of the "external" compartments and assemblies with minimization of the transfer of impact to the habitable module (Fig. 4). Similar solutions are implemented both on heavy machines, for example, Ranger from Universal Engineering (Fig. 5), and on light, including IVECO 65E19WM. With obvious rationality in conditions of limited mass, this technical solution still does not provide high survivability and preservation of mobility with relatively weak explosive devices, as well as bullet fire.
Rice. 3. Armored vehicles of the MRAP (Mine Resistant Ambush Protected) class have increased resistance to explosive devices and small arms fire
Rice. 4. Detachment of wheels, power plant and external equipment from the manned compartment when a car is blown up by a mine
Rice. 5. Heavy armored vehicles of the Ranger family of Universal Engineering
Rice. 6 Vehicle of the Typhoon family with an increased level of mine resistance
Simple and reliable, but not the most rational from the point of view of weight, is the use of heavy plate steel to protect the bottom. Lighter bottom structures with energy-absorbing elements (for example, hexagonal or rectangular tubular parts) are still used very limitedly.
Cars of the Typhoon family (Fig. 6), developed in Russia, also belong to the MRAP class. In this family of vehicles, almost all currently known technical solutions for ensuring mine protection are implemented:
- V-shaped bottom, - multilayer bottom of the crew compartment, mine sump, - internal floor on elastic elements, - the location of the crew at the maximum possible distance from the most probable place of detonation, - units and systems protected from the direct impact of weapons, - energy absorbing seats with seat belts and head restraints.
The work on the Typhoon family is an example of cooperation and an integrated approach to solving the problem of ensuring security in general and mine resistance in particular. The lead developer of the protection of cars created by the Ural Automobile Plant is NII Stali OJSC. The development of the general configuration and layout of cabins, functional modules, as well as energy-absorbing seats was carried out by JSC Evrotechplast. To perform numerical simulation of the explosion impact on the vehicle structure, specialists from Sarov Engineering Center LLC were involved.
The current approach to the formation of mine protection includes several stages. At the first stage, numerical modeling of the impact of explosion products on a sketched design is carried out. Further, the external configuration and the general design of the bottom, anti-mine pallets are clarified and their structure is being worked out (the development of structures is also carried out first by numerical methods, and then tested on fragments by real detonation).
In fig. 7 shows examples of numerical modeling of the impact of an explosion on various structures of mine action structures, performed by JSC "Research Institute of Steel" in the framework of work on new products. After the completion of the detailed design of the machine, various options for its undermining are simulated.
In fig. 8 shows the results of numerical simulations of a Typhoon car detonation performed by Sarov Engineering Center LLC. Based on the results of the calculations, the necessary modifications are made, the results of which are already verified by real detonation tests. This multistage approach allows one to assess the correctness of technical solutions at various stages of design and, in general, reduce the risk of design errors, as well as choose the most rational solution.
Rice. 7 Pictures of the deformed state of various protective structures in the numerical simulation of the impact of an explosion
Rice. 8 The picture of pressure distribution in the numerical simulation of the explosion of the car "Typhoon"
A common feature of the modern armored vehicles being created is the modularity of most systems, including protective ones. This makes it possible to adapt new samples of BTT to the intended conditions of use and, conversely, in the absence of any threats, to avoid unjustified
costs. With regard to mine protection, such modularity makes it possible to respond promptly to possible changes in the types and powers of explosive devices used and effectively solve one of the main problems of protecting modern armored vehicles with minimal costs.
Thus, on the problem under consideration, the following conclusions can be drawn:
- one of the most serious threats to armored vehicles in the most typical local conflicts today are mines and IEDs, which account for more than half of the losses of equipment;
- to ensure high mine protection of BTT, an integrated approach is required, including both layout and design, "circuit" solutions, as well as the use of special equipment, in particular, energy-absorbing crew seats;
- BTT models with high mine protection have already been created and are actively used in modern conflicts, which makes it possible to analyze the experience of their combat use and determine ways to further improve their design.
