Relict dynamic protection – anti-tandem capability with caveats
Instead of an introduction
The Relikt dynamic protection system is rightfully considered one of the most advanced domestic systems in its class. Compared to its Soviet predecessors, such as the Kontakt-1 and Kontakt-5, it truly represents a significant step forward in both effectiveness and the expanded range of threats it can counter. Therefore, when they say that the Relikt is the best in our series, it's essentially true.
So news that the ranks of the Relic carriers, which previously included only Tanks The T-80BVM and T-90M, as well as the BMPT Terminator, also included the Russian army's workhorse, the T-72B3M. It's certainly a nice addition. After all, it offers much better protection against sub-caliber and shaped-charge ammunition than the old Soviet hulks.
However, as often happens not only with us, they are trying to make a nearly universal solution out of a good and well-publicized means of protection, capable of equally reliably protecting a car from almost any classic ammunition (drones for obvious reasons we do not take this into account).
The T-80BVM was the most widely used carrier of the Relikt dynamic protection system before the special military operation.
This is especially true for tandem-warhead shaped-charge munitions—the Relikt has long had a reputation for providing virtually guaranteed protection against any tandem anti-tank munition. This rumor apparently arose from an overly literal interpretation of published specifications, advertising, and other information.
In reality, this interpretation is, of course, too straightforward and completely wrong. Relikt works against tandem HEAT munitions, but not against all of them. And we're not talking about some tricky projectiles with two or three pre-charges designed to penetrate tandem dynamic protection. Here, missiles, made according to the simple scheme “leading charge + main charge”.
Heavy missile systems
There's much talk these days about drones becoming the main threat to tanks on the battlefield, but traditional anti-tank weapons have by no means faded into the background. This is especially true for heavy anti-tank missile systems like the domestically developed Kornet.
The leading charges of its missiles, designed to penetrate dynamic armor, are quite powerful. And the penetrating power of the shaped-charge jets of their main charges, reaching up to 1300 mm of steel depending on the modification, is so great that a single hit is often enough to disable or completely destroy a tank along with its crew, while a tank equipped with protective equipment can withstand a dozen hits from drones with their low-power warheads.
Anti-tank missile system "Cornet-E"
So, for tanks with Relikt, such missiles can be dangerous due to the high residual penetration of their cumulative jets after penetrating dynamic protection.
To see this for yourself, you can read the article "The Relikt System—Reliable Defense" from Military Parade magazine, issue 5, 2011. In it, Valery Grigoryan, one of the creators of the Relikt and (at the time) president and scientific director of the Steel Research Institute, writes the following:
...Thus, the Relikt complex is based on the 4S23 high-sensitivity dynamic protection (DZ) element and a modern, more effective throwing scheme, in which the destructive and destabilizing effect on the striking elements of ammunition (the cumulative jet, the BPS core) is predominantly of relatively thick armor plates thrown in opposite directions.
The predominant contribution to this destructive effect comes from the plate thrown "in pursuit." Because "in pursuit" throwing is energetically more advantageous than "incoming" throwing, structures of this type achieve a significant (4-5 times) increase in resistance to APFSDS compared to the standard Kontakt-V ERA system. At the same time, the "anti-tandem" properties of such armor are significantly enhanced, meaning it gains resistance against the most modern tandem ATGMs like the TOW-2A, with a delay time of at least 400 μs and armor penetration behind the mounted anti-HEAT ERA of at least 1000 mm.
The predominant contribution to this destructive effect comes from the plate thrown "in pursuit." Because "in pursuit" throwing is energetically more advantageous than "incoming" throwing, structures of this type achieve a significant (4-5 times) increase in resistance to APFSDS compared to the standard Kontakt-V ERA system. At the same time, the "anti-tandem" properties of such armor are significantly enhanced, meaning it gains resistance against the most modern tandem ATGMs like the TOW-2A, with a delay time of at least 400 μs and armor penetration behind the mounted anti-HEAT ERA of at least 1000 mm.
We'll discuss what "chase-throwing" and "delay time of at least 400 μs" mean later, but the context makes it clear: with the Relikt, the tank receives protection from tandem TOW-2A missiles with penetration of at least 1000 millimeters of steel armor behind dynamic protection.
For more powerful missiles like the Kornet, this is insufficient. This is evidenced by a report, or rather, a bulletin, from the 38th Research Institute. It presents the results of tests of the Ukrainian "Nozh" dynamic protection system from a captured T-72AG tank and compares them with the "Relikt" system.
It contains the following data:
...During tests with armor-piercing sub-caliber projectiles, cumulative projectiles, and the Kornet ATGM, the following was established.
1. The characteristics of the "Nozh" ERA in terms of reducing the level of armor penetration by an armor-piercing sub-caliber projectile (APS) correspond to the "Kontakt-5" ERA.
2. The Nozh ERA is inferior to the Relikt ERA in terms of armor penetration: by at least 30% for APFSDS rounds, by at least 20% for cumulative rounds...
1. The characteristics of the "Nozh" ERA in terms of reducing the level of armor penetration by an armor-piercing sub-caliber projectile (APS) correspond to the "Kontakt-5" ERA.
2. The Nozh ERA is inferior to the Relikt ERA in terms of armor penetration: by at least 30% for APFSDS rounds, by at least 20% for cumulative rounds...
And here's a more interesting conclusion:
... ATGM "Kornet" - parity.
In other words, the Nozh dynamic protection system, which was never advertised as capable of resisting tandem HEAT munitions, is on par with the Relikt anti-tandem system when hit by a Kornet missile. Clearly, this doesn't mean they offer equal protection against similar weapons; rather, they offer no guarantee.
This doesn't mean Relikt is complete nonsense. It merely defines the limits of its "powers": if a tank has powerful passive armor, the system will help, but if it doesn't, it might not. But it's not just about armor penetration.
Throwing plates "in pursuit"
As is well known, mass-produced domestic dynamic protection systems operate against shaped-charge munitions (including kinetic ones) by propelling steel plates with the energy of the explosion. Therefore, one of the factors determining the effectiveness of such systems is the time the plate is in the trajectory of the shaped-charge jet—the time during which the plate impacts the jet, disrupting and destabilizing it in flight.
For systems like Kontakt-1 and Kontakt-5, this time is literally measured in a few hundred to two hundred microseconds. This is sufficient to counter single-warhead shaped-charge munitions—the armor penetration of their shaped-charge jets will be dramatically reduced, saving the tank from destruction.
However, classic tandem shaped-charge munitions use two shaped charges. The first, the leading charge, detonates instantly and triggers the reactive armor. The second, the main charge, detonates afterward with a significant delay, which can reach 400 microseconds or more. As a result, the reactive armor has virtually no effect on the shaped-charge jet of the main charge, since the plates being launched already depart from its trajectory due to this delay.
To counter tandem shaped-charge munitions and enhance protection against sub-caliber projectiles, Relikt modules utilize two thick steel plates—a front plate and a rear plate—separated by an explosive-filled reactive armor element. Upon detonation, the front plate is propelled toward the incoming projectile, while the rear plate is propelled in the opposite direction, as if "in pursuit," as Grigoryan described it.
A diagram of the Relikt dynamic protection system. The thick metal plates are visible in the modules.
This significantly increases the active protection's impact time: while one plate begins to move out of the attacker's path, the second enters it. As a result, the plates have time to engage not only the cumulative jet of the tandem munition's leading charge, but also the main charge.
As a result, as Grigoryan himself writes, the Relikt is effective against tandem shaped-charge munitions with a delay between the detonation of the leading and main warheads of at least 400 microseconds. This is certainly sufficient for missiles like the TOW-2A. However, as the delay increases, the effectiveness of systems like the Relikt drops sharply. This is evident in the image below.
The dependence of the dynamic protection efficiency coefficient (Kdz) on the detonation delay time of the main charge of a tandem munition (μs). Source: "Specific Issues of Terminal Ballistics."
In other words, the Relikt's effectiveness against tandem HEAT munitions lies within a fairly narrow range, determined by the main charge's detonation delay time. For relatively older weapons like the TOW-2A, this is sufficient, but given the advances in more recent HEAT weapons, things are, shall we say, not entirely rosy.
Grigoryan himself, along with his co-authors, wrote in the book “Special Issues of Terminal Ballistics” (2006) that modifications of second-generation tandem cumulative destructive weapons already have a tendency to increase the delay time between the detonations of the main and leading charges:
The second generation of tandem ammunition is characterized by an increase in the delay time (500... 1500 µs) of the pre-charge response relative to the main charge, ensured by an even greater separation of charges, an electronic delay, and the implementation of the principle of pre-contact initiation of the main charge.
So, although Relict has “anti-tandem” properties, it comes with reservations.
Conclusions
Overall, the Relikt is actually a pretty decent dynamic protection system. It's not some useless piece of junk dreamed up by domestic designers, but rather the most that could be squeezed out of a modular design that requires absolutely no modifications to the tank other than welding on mounts.
Within these limits, it's quite adequate. It increases the tank's protection against sub-caliber projectiles and shaped-charge weapons, including tandem warheads, though not all of them. More can't be expected of it, as heavy explosive reactive armor is required to counter large-caliber heavy anti-tank missiles with tandem warheads and munitions with a long fuse delay.
Examples of such heavy complexes are the Omsk project “Cactus" and the Ukrainian dynamic protection "Duplet", implemented in small series - both require a thorough modernization of the tanks with partial removal of armor packages (yes, it is necessary to partially cut out the armor and replace it with multi-layer dynamic protection with heavy shock absorbers in the form of steel plates, etc.), which is very expensive and labor-intensive.
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