Application of Non-Explosive Reactive Armor in Tank Protection Systems under Conditions of Limited Availability or Insufficient Supply of Dynamic Armor Elements

 

Application of Non-Explosive Reactive Armor in Tank Protection Systems under Conditions of Limited Availability or Insufficient Supply of Dynamic Armor Elements
(Sychev V.V.) 

 

Due to the insufficient availability of dynamic armor elements (DAE), JSC "NII Stali" has proposed the use of non-explosive reactive armor (NERA). NERA is the most effective means of protection against shaped-charge munitions after explosive-based dynamic armor elements (DAE with explosives). Generally, the NERA design consists of an inert filler sandwiched between thin steel plates.

The operating principle of both NERA and DAE is based on the partial disruption of a penetrating shaped-charge jet through the movement of thin steel plates at the point of contact with the jet. In DAE, this movement is driven by the explosion of the embedded explosives. In NERA, the plates move due to the generation of a powerful shock wave within the inert layer between the steel sheets, causing localized displacement (bulging) of the plates near the penetration point. When the NERA package is angled, this movement shifts undamaged sections of the plates into the jet’s path, breaking it apart and significantly reducing its penetration capability into the protective structure (Figure 1). 

 

 

Figure 1 - Effect of NERA on a Shaped-Charge Jet 

 

Tests were conducted using mounted "Kontakt-1" dynamic armor containers (NKDZ), additional side armor blocks (BDZ), and turret armor blocks (BDZ) equipped with NERA elements instead of standard 4S20 and 4S22 DAE. The locations of the tested protective structures are illustrated using the example of the T-72B3M tank (Figure 2). 

 

 Figure 2 - Arrangement of Protective Elements on the T-72B3M Tank 

 

NERA consists of two 2-mm structural steel plates with a 6-mm organic glass (plexiglass) plate placed between them. The assembly is held together with tape, ensuring tight contact between the plates. The dimensions of the plates are 250x130 mm, matching those of the 4S20 and 4S22 DAE. The thickness of the assembled NERA element also corresponds to that of the DAE, allowing it to be installed in protective systems.

Tests of the "Kontakt-1" NKDZ protective structures were conducted under conditions of standard DAE equipping, full replacement of DAE with NERA, and partial replacement (50%) of DAE with NERA. Similarly, tests of the side and turret BDZ protective structures were conducted with standard DAE equipping and full replacement of DAE with NERA.

For comparative evaluation, warheads of PG-9 and PG-7 anti-tank grenades were used, with tests performed via static detonation to ensure maximum result reliability. In each test, the residual penetration depth of the shaped-charge jet into the armor barrier behind the respective protective structure was measured (Figures 3-5). Based on the residual penetration depth, the increase in resistance was calculated, and the relative effectiveness of the protective structure was assessed.

 

 

Figure 3 - Test Conditions for "Kontakt-1" NKDZ

 

 

 

 
Figure 4 - Test Conditions for Tank Turret BDZ

 

 
Figure 5 - Test Conditions for Tank Side BDZ

Evaluation of "Kontakt-1" NKDZ Protective Structure Test Results

The increase in resistance was determined using the average penetration capabilities of PG-9S and PG-7L shaped-charge grenades. Test results yielded an average increase in resistance.

Given the known resistance increase of the "Kontakt-1" NKDZ container equipped with 4S20 or 4S22 DAE, the resistance level when using only NERA elements was calculated to be 71% of the standard level. When NERA was used in combination with DAE, the resistance level reached 86% of the standard.

For comparison, the resistance increase was also evaluated for cases where the NKDZ container was filled with sand or concrete, or left empty. A comparison of resistance increase values is presented in Figure 6. 

 

 

Figure 6 - Comparison of Resistance Increase for "Kontakt-1" NKDZ Container 

 

Additionally, a calculated assessment of the NKDZ container’s mass was conducted for cases of equipping with DAE, NERA elements, sand filling, and an unequipped state. The results are shown in Figure 7. 

 

 

Figure 7 - Comparison of "Kontakt-1" NKDZ Container Mass

Evaluation of Tank Side BDZ Protective Structure Test Results

The increase in resistance was determined using the average penetration capability of the PG-7L. Test results provided an average resistance increase.

Given the known resistance increase of the tank side protective structure with BDZ equipped with 4S20 or 4S22 DAE, the resistance level when using only NERA elements was calculated to be 92% of the standard level.

For comparison, the resistance increase was evaluated for cases where the additional protection container was filled with sand or concrete, or left empty. A comparison of resistance increase values is presented in Figure 8. 

 

 

Figure 8 - Comparison of Resistance Increase for Side BDZ 

 

A calculated assessment of the side BDZ mass was also conducted for equipping with DAE, NERA elements, sand filling, and an unequipped state. The results are shown in Figure 9.

Figure 9 - Comparison of Side Armor Mass

Evaluation of Tank Turret BDZ Protective Structure Test Results

The increase in resistance was determined using the average penetration capability of the PG-9S. Test results provided an average resistance increase.

Given the known resistance increase of the tank turret protective structure with BDZ equipped with 4S20 or 4S22 DAE, the resistance level when using only NERA elements was calculated to be 69% of the standard level.

For comparison, the resistance increase was evaluated for cases where the container was filled with sand or concrete, or left empty. A comparison of resistance increase values is presented in Figure 10.

 

 

Figure 10 - Comparison of Resistance Increase for Turret BDZ 

 

A calculated assessment of the turret BDZ mass was also conducted for equipping with DAE, NERA elements, sand filling, and an unequipped state. The results are shown in Figure 11.

 

 

Figure 11 - Comparison of Turret BDZ Mass

Conclusions

The most effective method of equipping mounted dynamic armor kits and additional armor blocks is their standard equipping with DAE, while an acceptable alternative is combined equipping with DAE and NERA.

Recommendations

1. As a complete replacement for DAE in cases of insufficient supply, NERA is permissible only in the side BDZ protective structure of the tank.
2. In the "Kontakt-1" NKDZ and turret BDZ protective structures, NERA is permissible only when used in combination with DAE.
3. The closest alternative is filling dynamic armor containers with dense materials such as sand or concrete, though the effectiveness of this solution is 10-40% of the standard level, with a higher mass.
4. Installing NERA elements in built-in dynamic armor systems like "Kontakt-5" or "Relikt" is impractical—only DAE should be used.